Search Results: "Jonathan McDowell"

I mentioned in the post about upgrading my home internet that part of the work I did was creating a read-only Debian root with a squashfs image. This post covers the details of how I boot with that image; a later post will cover how I build the squashfs image. First, David Reader kindly pointed me at his rodebian setup, which was helpful in making me think about the whole problem but ultimately not the direction I went. Primarily because on the old router (an RB3011) I am space constrained, with only 120M of usable flash, and so ideally I wanted as much as possible of the system in a well compressed filesystem. squashfs seemed like the best option for that, and ultimately I ended up with a 39M image. I ve then used overlayfs to mount a tmpfs, so I get what looks like a writeable system without having to do too many tweaks to the actual install. On the plus side I can then see exactly what is getting written where and decide whether I need to update something in the squashfs. I don t boot with an initrd - for initial testing I booted directly off a USB stick. I ve actually ended up continuing to do this in production, because I ve had no pressing reason to move it all to booting off internal flash (I ve ended up with a Sandisk SDCZ430-032G-G46 which is tiny). However nothing I m going to describe is dependent on that - this would work perfectly well for a initial UBIFS rootfs on internal NAND. So the basic overview is I boot off a minimal rootfs, mount a squashfs, create an appropriate tmpfs, mount an overlayfs that combines the two, then pivotroot into the overlayfs and exec its init so it becomes the rootfs. For the minimal rootfs I started with busybox, in particular I used the armhf busybox-static package from Debian. My RB5009 is an ARM64, but I wanted to be able to test on the RB3011 as well, which is ARMv7. Picking an armhf binary for the minimal rootfs lets me use the same image for both. Using the static build helps reduce the number of pieces involved in putting it all together. The busybox binary goes in /bin. I was able to cheat and chroot into the empty rootfs and call busybox --install -s to create symlinks for all the tools it provides, but I could have done this manually. There s only a handful that are actually needed, but it s amazing how much is crammed into a 1.2M binary. /sbin/init is a shell script:

Contents

#!/bin/ash
# Make sure we have a sane date
if [ -e /data/saved-date ]; then
        CURRENT_DATE=$(date -Iseconds)
        if [ "$ CURRENT_DATE:0:4 " -lt "2022" -o \
                        "$ CURRENT_DATE:0:4 " -gt "2030" ]; then
                echo Setting initial date
                date -s "$(cat /data/saved-date)"
        fi
fi
# Work out what platform we're on
ARCH=$(uname -m)
if [ "$ ARCH " == "aarch64" ]; then
        ARCH=arm64
else
        ARCH=armhf
fi
# Mount a tmpfs to store the changes
mount -t tmpfs root-rw /mnt/overlay/rw
# Make the directories we need in the tmpfs
mkdir /mnt/overlay/rw/upper
mkdir /mnt/overlay/rw/work
# Mount the squashfs and build an overlay root filesystem of it + the tmpfs
mount -t squashfs -o loop /data/router.$ ARCH .squashfs /mnt/overlay/lower
mount -t overlay \
        -o lowerdir=/mnt/overlay/lower,upperdir=/mnt/overlay/rw/upper,workdir=/mnt/overlay/rw/work \
        overlayfs-root /mnt/root
# Build the directories we need within the new root
mkdir /mnt/root/mnt/flash
mkdir /mnt/root/mnt/overlay
mkdir /mnt/root/mnt/overlay/lower
mkdir /mnt/root/mnt/overlay/rw
# Copy any stored state
if [ -e /data/state.$ ARCH .tar ]; then
        echo Restoring stored state
        cd /mnt/root
        tar xf /data/state.$ ARCH .tar
fi
cd /mnt/root
pivot_root . mnt/flash
echo Switching into root filesystem
exec chroot . sh -c "$(cat <<END
mount --move /mnt/flash/mnt/overlay/lower /mnt/overlay/lower
mount --move /mnt/flash/mnt/overlay/rw /mnt/overlay/rw
exec /sbin/init
END
)"

Most of what the script is doing is sorting out the squashfs + tmpfs backed overlayfs that becomes the full root filesystems, but there are a few other bits to note. First, we pick up a saved date from /data/saved-date - the router has no RTC and while it ll sort itself out with NTP once it gets networking up it s useful to make sure we don t end up comically far in the past or future. Second, the script looks at what architecture we re running and picks up an appropriate squashfs image from /data based on that. This let me use the same USB stick for testing on both the RB3011 and the RB5011. Finally we allow for a /data/state.$ ARCH .tar file to let us pick up changes to the rootfs at boot time - this prevents having to rebuild the squashfs image every time there s a persistent change. The other piece that doesn t show up in the script is that the kernel and its modules are all installed into this initial rootfs (and then symlinked from the squashfs). This lets me build a mostly modular kernel, as long as all the necessary drivers to mount the USB stick are built in. Once the system is fully booted the initial rootfs is available at /mnt/flash, by default mounted read-only (to avoid inadvertent writes), but able to be remounted to update the squashfs image, install a new kernel, or update the state tarball. /mnt/overlay/rw/upper/ is where updates to the overlayfs are written, which provides an easy way to see what files are changing, initially to determine what might need tweaked in the squashfs creation process and subsequently to be able to see what needs updated in the state tarball.

I am old enough to remember when BPF meant the traditional Berkeley Packet Filter, and was confined to filtering network packets. It s grown into much, much, more as eBPF and getting familiar with it so that I can add it to the suite of tips and tricks I can call upon has been on my to-do list for a while. To this end I was lucky enough to attend a live walk through of bpftrace last year. bpftrace is a high level tool that allows the easy creation and execution of eBPF tracers under Linux. Recently I ve been working on updating the RetroArch packages in Debian and as I was doing so I realised there was a need to update the quite outdated retroarch-assets package, which contains various icons and images used for the user interface. I wanted to try and re-generate as many of the artefacts as I could, to ensure the proper source was available. However it wasn t always clear which files were actually needed and which were either source or legacy. So I wanted to trace file opens by retroarch and see when it was failing to find files. Traditionally this is something I d have used strace for, but it seemed like a great opportunity to try out bpftrace. It turns out bpftrace ships with an example, opensnoop.bt which provided details of hooking the open syscall entry + exit and providing details of all files opened on the system. I only wanted to track opens by the retroarch binary that failed, so I made a couple of modifications:

retro-failed-open-snoop.bt

#!/usr/bin/env bpftrace
/*
 * retro-failed-open-snoop - snoop failed opens by RetroArch
 *
 * Based on:
 * opensnoop	Trace open() syscalls.
 *		For Linux, uses bpftrace and eBPF.
 *
 * Copyright 2018 Netflix, Inc.
 * Licensed under the Apache License, Version 2.0 (the "License")
 *
 * 08-Sep-2018	Brendan Gregg	Created this.
 */
BEGIN
 
	printf("Tracing open syscalls... Hit Ctrl-C to end.\n");
	printf("%-6s %-16s %3s %s\n", "PID", "COMM", "ERR", "PATH");
 
tracepoint:syscalls:sys_enter_open,
tracepoint:syscalls:sys_enter_openat
 
	@filename[tid] = args->filename;
 
tracepoint:syscalls:sys_exit_open,
tracepoint:syscalls:sys_exit_openat
/@filename[tid]/
 
	$ret = args->ret;
	$errno = $ret > 0 ? 0 : - $ret;
	if (($ret <= 0) && (strncmp("retroarch", comm, 9) == 0) )  
		printf("%-6d %-16s %3d %s\n", pid, comm, $errno,
		    str(@filename[tid]));
	 
	delete(@filename[tid]);
 
END
 
	clear(@filename);
 

I had to install bpftrace (apt install bpftrace) and then I ran bpftrace -o retro.log retro-failed-open-snoop.bt as root and fired up retroarch as a normal user.

bpftrace failed open log for retroarch

Attaching 6 probes...
Tracing open syscalls... Hit Ctrl-C to end.
PID    COMM             ERR PATH
 retroarch          2 /usr/lib/x86_64-linux-gnu/pulseaudio/glibc-hwcaps/x86-64-v2/lib
 retroarch          2 /usr/lib/x86_64-linux-gnu/pulseaudio/tls/x86_64/x86_64/libpulse
 retroarch          2 /usr/lib/x86_64-linux-gnu/pulseaudio/tls/x86_64/libpulsecommon-
 retroarch          2 /usr/lib/x86_64-linux-gnu/pulseaudio/tls/x86_64/libpulsecommon-
 retroarch          2 /usr/lib/x86_64-linux-gnu/pulseaudio/tls/libpulsecommon-16.1.so
 retroarch          2 /usr/lib/x86_64-linux-gnu/pulseaudio/x86_64/x86_64/libpulsecomm
 retroarch          2 /usr/lib/x86_64-linux-gnu/pulseaudio/x86_64/libpulsecommon-16.1
 retroarch          2 /usr/lib/x86_64-linux-gnu/pulseaudio/x86_64/libpulsecommon-16.1
 retroarch          2 /etc/gcrypt/hwf.deny
 retroarch          2 /lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2/libgamemode.so.0
 retroarch          2 /lib/x86_64-linux-gnu/tls/x86_64/x86_64/libgamemode.so.0
 retroarch          2 /lib/x86_64-linux-gnu/tls/x86_64/libgamemode.so.0
 retroarch          2 /lib/x86_64-linux-gnu/tls/x86_64/libgamemode.so.0
 retroarch          2 /lib/x86_64-linux-gnu/tls/libgamemode.so.0
 retroarch          2 /lib/x86_64-linux-gnu/x86_64/x86_64/libgamemode.so.0
 retroarch          2 /lib/x86_64-linux-gnu/x86_64/libgamemode.so.0
 retroarch          2 /lib/x86_64-linux-gnu/x86_64/libgamemode.so.0
 retroarch          2 /lib/x86_64-linux-gnu/libgamemode.so.0
 retroarch          2 /usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2/libgamemode.so
 retroarch          2 /usr/lib/x86_64-linux-gnu/tls/x86_64/x86_64/libgamemode.so.0
 retroarch          2 /usr/lib/x86_64-linux-gnu/tls/x86_64/libgamemode.so.0
 retroarch          2 /usr/lib/x86_64-linux-gnu/tls/x86_64/libgamemode.so.0
 retroarch          2 /usr/lib/x86_64-linux-gnu/tls/libgamemode.so.0
 retroarch          2 /usr/lib/x86_64-linux-gnu/x86_64/x86_64/libgamemode.so.0
 retroarch          2 /usr/lib/x86_64-linux-gnu/x86_64/libgamemode.so.0
 retroarch          2 /usr/lib/x86_64-linux-gnu/x86_64/libgamemode.so.0
 retroarch          2 /usr/lib/x86_64-linux-gnu/libgamemode.so.0
 retroarch          2 /lib/glibc-hwcaps/x86-64-v2/libgamemode.so.0
 retroarch          2 /lib/tls/x86_64/x86_64/libgamemode.so.0
 retroarch          2 /lib/tls/x86_64/libgamemode.so.0
 retroarch          2 /lib/tls/x86_64/libgamemode.so.0
 retroarch          2 /lib/tls/libgamemode.so.0
 retroarch          2 /lib/x86_64/x86_64/libgamemode.so.0
 retroarch          2 /lib/x86_64/libgamemode.so.0
 retroarch          2 /lib/x86_64/libgamemode.so.0
 retroarch          2 /lib/libgamemode.so.0
 retroarch          2 /usr/lib/glibc-hwcaps/x86-64-v2/libgamemode.so.0
 retroarch          2 /usr/lib/tls/x86_64/x86_64/libgamemode.so.0
 retroarch          2 /usr/lib/tls/x86_64/libgamemode.so.0
 retroarch          2 /usr/lib/tls/x86_64/libgamemode.so.0
 retroarch          2 /usr/lib/tls/libgamemode.so.0
 retroarch          2 /usr/lib/x86_64/x86_64/libgamemode.so.0
 retroarch          2 /usr/lib/x86_64/libgamemode.so.0
 retroarch          2 /usr/lib/x86_64/libgamemode.so.0
 retroarch          2 /usr/lib/libgamemode.so.0
 retroarch          2 /lib/x86_64-linux-gnu/libgamemode.so
 retroarch          2 /usr/lib/x86_64-linux-gnu/libgamemode.so
 retroarch          2 /lib/libgamemode.so
 retroarch          2 /usr/lib/libgamemode.so
 retroarch          2 /lib/x86_64-linux-gnu/libdecor-0.so
 retroarch          2 /usr/lib/x86_64-linux-gnu/libdecor-0.so
 retroarch          2 /lib/libdecor-0.so
 retroarch          2 /usr/lib/libdecor-0.so
 retroarch          2 /etc/drirc
 retroarch          2 /home/noodles/.drirc
 retroarch          2 /etc/drirc
 retroarch          2 /home/noodles/.drirc
 retroarch          2 /usr/lib/x86_64-linux-gnu/dri/tls/iris_dri.so
 retroarch          2 /lib/x86_64-linux-gnu/../lib/glibc-hwcaps/x86-64-v2/libedit.so.
 retroarch          2 /lib/x86_64-linux-gnu/../lib/tls/x86_64/x86_64/libedit.so.2
 retroarch          2 /lib/x86_64-linux-gnu/../lib/tls/x86_64/libedit.so.2
 retroarch          2 /lib/x86_64-linux-gnu/../lib/tls/x86_64/libedit.so.2
 retroarch          2 /lib/x86_64-linux-gnu/../lib/tls/libedit.so.2
 retroarch          2 /lib/x86_64-linux-gnu/../lib/x86_64/x86_64/libedit.so.2
 retroarch          2 /lib/x86_64-linux-gnu/../lib/x86_64/libedit.so.2
 retroarch          2 /lib/x86_64-linux-gnu/../lib/x86_64/libedit.so.2
 retroarch          2 /lib/x86_64-linux-gnu/../lib/libedit.so.2
 retroarch          2 /etc/drirc
 retroarch          2 /home/noodles/.drirc
 retroarch          2 /etc/drirc
 retroarch          2 /home/noodles/.drirc
 retroarch          2 /etc/drirc
 retroarch          2 /home/noodles/.drirc
 retroarch          2 /home/noodles/.Xdefaults-udon
 retroarch          2 /home/noodles/.icons/default/cursors/00000000000000000000000000
 retroarch          2 /home/noodles/.icons/default/index.theme
 retroarch          2 /usr/share/icons/default/cursors/000000000000000000000000000000
 retroarch          2 /usr/share/pixmaps/default/cursors/0000000000000000000000000000
 retroarch          2 /home/noodles/.icons/Adwaita/cursors/00000000000000000000000000
 retroarch          2 /home/noodles/.icons/Adwaita/index.theme
 retroarch          2 /usr/share/icons/Adwaita/cursors/000000000000000000000000000000
 retroarch          2 /usr/share/pixmaps/Adwaita/cursors/0000000000000000000000000000
 retroarch          2 /home/noodles/.icons/hicolor/cursors/00000000000000000000000000
 retroarch          2 /home/noodles/.icons/hicolor/index.theme
 retroarch          2 /usr/share/icons/hicolor/cursors/000000000000000000000000000000
 retroarch          2 /usr/share/pixmaps/hicolor/cursors/0000000000000000000000000000
 retroarch          2 /usr/share/pixmaps/hicolor/index.theme
 retroarch          2 /home/noodles/.XCompose
 retroarch          2 /home/noodles/.icons/default/cursors/00000000000000000000000000
 retroarch          2 /home/noodles/.icons/default/index.theme
 retroarch          2 /usr/share/icons/default/cursors/000000000000000000000000000000
 retroarch          2 /usr/share/pixmaps/default/cursors/0000000000000000000000000000
 retroarch          2 /home/noodles/.icons/Adwaita/cursors/00000000000000000000000000
 retroarch          2 /home/noodles/.icons/Adwaita/index.theme
 retroarch          2 /usr/share/icons/Adwaita/cursors/000000000000000000000000000000
 retroarch          2 /usr/share/pixmaps/Adwaita/cursors/0000000000000000000000000000
 retroarch          2 /home/noodles/.icons/hicolor/cursors/00000000000000000000000000
 retroarch          2 /home/noodles/.icons/hicolor/index.theme
 retroarch          2 /usr/share/icons/hicolor/cursors/000000000000000000000000000000
 retroarch          2 /usr/share/pixmaps/hicolor/cursors/0000000000000000000000000000
 retroarch          2 /usr/share/pixmaps/hicolor/index.theme
 retroarch          2 /usr/share/libretro/assets/xmb/monochrome/png/disc.png
 retroarch          2 /usr/share/libretro/assets/xmb/monochrome/sounds
 retroarch          2 /usr/share/libretro/assets/sounds
 retroarch          2 /sys/class/power_supply/ACAD
 retroarch          2 /sys/class/power_supply/ACAD
 retroarch          2 /usr/share/libretro/assets/xmb/monochrome/png/disc.png
 retroarch          2 /usr/share/libretro/assets/ozone/sounds
 retroarch          2 /usr/share/libretro/assets/sounds

This was incredibly useful - the only theme image I was missing is disc.png from XMB Monochrome (which fails to have SVG source). I also discovered the runtime optional loading of GameMode. This is available in Debian so it was a simple matter to add libgamemode0 to the binary package Recommends. So, a very basic example of using bpftrace, but a remarkably useful intro to it from my point of view!

There is a move to Bring Back Blogging and having recently sorted out my own FreshRSS install I am completely in favour of such a thing. RSS feeds with complete posts, for preference, not just a teaser intro sentence/paragraph. It s also a reminder to me that I should blog more, and what better way to start 2023 than with my traditional recap of my Free Software activities in 2022. For previous years see 2019, 2020 + 2021

Conferences I attended DebConf22 in Prizen, Kosova this year, and finally hit the end of my luck in avoiding COVID. 0/10, would not recommend. Thankfully I didn t come down with symptoms until I got home (I felt fine and tested negative on arrival home, then started to feel terrible the next day and tested again), so I was able to enjoy the conference itself. I also made it to Linux Security Summit Europe 2022, which aligned with work related bits and was interesting. I suspect I would have been better going to LPC 2022 for the hallway track, though I did manage to get some overlap with folk being in town given that both were the same week.

Debian Most of my contributions to Free software continue to happen within Debian. We continue to operate a roughly 3 month rotation for Debian Keyring in terms of handling the regular updates, and I dealt with 2022.03.24, 2022.06.26, 2022.08.11, 2022.09.24, 2022.09.25 + 2022.12.24. There were a few out of cycle updates this year and I handled a couple of them. My other contributions are largely within the Debian Electronics Packaging Team. gcc-xtensa-lx106 saw a few updates, to GCC 11 + enabling D (10 + 11), then to GCC 12 (12). binutils-xtensa-lx106 got some minor packaging cleanups, which also served to force a rebuild with the current binutils source (5). libsigrokdecode got an upload to enable building with Python 3.10 (0.5.3-3). Related, I updated sdcc to a new upstream version (4.2.0+dfsg-1) - it s used for the sigrok-firmware-fx2lafw package and I do have a tendency to play with microcontrollers, so it s good to have a recent version available in the archive. I continue to pay attention to OpenOCD, with a minor set of updates to pull in some fixes from master (0.11.0-2). I was pleased to see the release process for 0.12.0 kick off and have been uploading RCs as they come out (0.12.0~rc1-1, 0.12.0~rc2-1 + 0.12.0~rc3-1). Upstream have been interested in the upcoming bookworm release cycle and I m hopeful we ll get 0.12.0 proper in before freeze. libjaylink also saw an upstream release (0.3.1-1). Package upload sponsorship isn t normally something I get involved with, because I find I have to spend a lot of time checking over things before I m comfortable doing the upload. However I did sponsor an initial upload for sugarjar and an update for mgba (0.10.0+dsfg-1, currently stuck in NEW). Credit to Michel for dealing swiftly with my review comments, and Ryan for producing a nicely reviewable set of changes. As part of the Data Protection Team I responded to various inbound queries to that team. There was also some discussion on debian-vote as part of the DPL election that I engaged with, as well as discussions at DebConf about how we can do things better. For Debian New Members I m mostly inactive as an application manager - we generally seem to have enough available recently. If that changes I ll look at stepping in to help, but I don t see that happening (it got close this year but several people had stood up before I got around to offering). I continue to be involved in Front Desk, having various conversations throughout the year with the rest of the team and occasionally approving some of the checks for new applicants. Towards the end of the year I got involved with the Debian Games Team, largely because I m keen to try and get my Kodi working with libretro based emulators - I d really like to be able to play old style games from the same interface as I can engage with locally stored movies, music and TV. It turns out there are a lot of moving pieces to make that happen, some missing from Debian and others in need of some TLC. I updated retroarch to current upstream (1.13.0+dfsg-1 + 1.13.0+dfsg-2) but while I was doing so upstream did another release. I plan on uploading 1.14.0 once 1.13.0 has migrated to testing. It turned out I also needed to update libretro-core-info (1.13.0-1) and retroarch-assets (1.7.6+git20221024+dfsg-1). In terms of actual emulators I pulled in new versions for genesisplusgx (1.7.4+git20221128-1) and libretro-bsnes-mercury (094+git20220807-1). On the Kodi side I haven t uploaded anything yet. I ve filed an ITP for rcheevos, which is a dependency for game.libretro and I have a fledgling package for game.libretro that I finally got working today. I m not sure if I can get it cleaned up enough in time to make the bookworm release, but I m hoping that at least the libretro piece is in a bit better shape now (though I m aware there are more emulator cores that could do with being updated).

Linux This year was a quiet year for personal Linux contributions. I submitted a minor fix for the qca8081 PHY with speeds lower than 2.5Gb/s that caused me issues on my RB5009.

Personal projects 2022 finally saw a minor releases of onak, 0.6.2, which resulted in a corresponding Debian upload (0.6.2-1). It has a couple of bug fixes but nothing major.. As I said last year it s not dead, just resting, but Sequoia PGP is probably where you should be looking for a modern OpenPGP implementation. I added some basic Debian packaging to mqtt-arp - I didn t bother uploading it as it s a fairly niche package, but I m using it locally.

Ever since the demise of Google Reader I have been looking for a suitable replacement RSS reader. In the past I used to use Liferea but that was when I used a single desktop machine; these days I want to be able to read on my phone and multiple machines. I moved to Feedly and it s been mostly ok, but I m hitting the limit of feeds available in the free tier, and $72/year is a bit more than I can justify to myself. Especially when I have machines already available to me where I could self host something. The problem, of course, is what to host. It seems the best options are all written in PHP, so I had to get over my adverse knee-jerk reaction to that. I ended up on FreshRSS but if it hadn t worked out I d have tried TinyTinyRSS. Of course I m hosting on Debian, and the machine I chose to use was already running nginx and PostgreSQL. So I needed to install PHP:

$ sudo apt install php7.4-fpm php-curl php-gmp php-intl php-mbstring \
	php-pgsql php-xml php-zip

I put my FreshRSS install in /srv/freshrss so I grabbed the 1.20.2 release from GitHub (actually 1.20.1 at the time, but I ve upgraded to the latest since) and untared it in there. I gave www-data access to the data directory (sudo chown -R www-data /srv/freshrss/data) (yes, yes, I could have created a new user specifically for FreshRSS, but I ve chosen not to for now). There s no actual need to configure things up on the filesystem, you can do the initial setup from the web interface. Which is where the trouble came. I ve been an Apache user since 1998 and as a result it s what I know and what I go to. nginx is new to me. And I wanted my FreshRSS instance to live in a subdirectory of an existing TLS-enabled host, rather than have it s own hostname. Now, at least FreshRSS copes with this (unlike far too many other projects), you just have to configure your webserver correctly. Which took me more experimentation than I d like, but I ve ended up with the following snippet:

    # PHP files handling
    location ~ ^/freshrss/.+?\.php(/.*)?$  
        root /srv/freshrss/p;
        fastcgi_pass unix:/run/php/php-fpm.sock;
        fastcgi_split_path_info ^/freshrss(/.+\.php)(/.*)?$;
        set $path_info $fastcgi_path_info;
        fastcgi_param PATH_INFO $path_info;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
     
    location ~ ^/freshrss(/.*)?$  
        root /srv/freshrss/p;
        try_files $1 /freshrss$1/index.php$is_args$args;
     

Other than the addition of the freshrss prefix this ends up differing slightly from the FreshRSS webserver configuration example. I ended up having to make the path info on the fastcgi_split_path_info optional, and my try_files in the bare directory location directive needed $is_args$args added or I just ended up in a redirect loop because the session parameters didn t get passed through. I m sure there s a better way to do it, but I did a bunch of searching and this is how I ended up making it work. Before firing up the web configuration I created a suitable database:

$ sudo -Hu postgres psql
psql (13.8 (Debian 13.8-0+deb11u1))
Type "help" for help.
postgres=# create database freshrss;
CREATE DATABASE
postgres=# create user freshrss with encrypted password 'hunter2';
CREATE ROLE
postgres=# grant all privileges on database freshrss to freshrss;
GRANT
postgres=# \q

I ran through the local configuration, creating myself a user and adding some feeds, then created a cronjob to fetch updates hourly and keep a log:

# mkdir /var/log/freshrss
# chown :www-data /var/log/freshrss
# chmod 775 /var/log/freshrss
# cat > /etc/cron.d/freshrss-refresh <EOF
33 * * * * www-data /srv/freshrss/app/actualize_script.php > /var/log/freshrss/update-$(date --iso-8601=minutes).log 2>&1
EOF

Experiences so far? Reasonably happy. The interface seems snappy enough, and works well both on mobile and desktop. I m only running a single user instance at present, but am considering opening it up to some other folk and will see how that scales. And it clearly indicated a number of my feeds that were broken, so I ve cleaned some up that are still around and deleted the missing ones. Now I just need to figure out what else I should be subscribed to that I ve been putting off due to the Feedly limit!

Over the weekend I released a new version of onak, my OpenPGP compatible keyserver. At 2 years since the last release that means I ve at least managed to speed up a bit, but it s fair to say its development isn t a high priority for me at present. This release is largely driven by a collection of minor fixes that have built up, and the knowledge that a Debian freeze is coming in the new year. The fixes largely revolve around the signature verification that was introduced in 0.6.0, which makes it a bit safer to run a keyserver by only accepting key material that can be validated. All of the major items I wanted to work on post 0.6.0 remain outstanding. For the next release I d like to get some basic Stateless OpenPGP Command Line Interface support integrated. That would then allow onak to be tested with the OpenPGP interoperability test suite, which has recently added support for verification only OpenPGP implementations. I realise most people like to dismiss OpenPGP, and the tooling has been fairly dreadful for as long as I ve been using it, but I do think it fills a space that no competing system has bothered to try and replicate. And that s the web of trust, which helps provide some ability to verify keys without relying on (but also without preventing) a central authority to do so. Anyway. Available locally or via GitHub.

0.6.2 - 27th November 2022

Don t take creation time from unhashed subpackets

Fix ECDSA/SHA1 signature check

Fix handling of other signature requirement

Fix deletion of keys with PostgreSQL backend

Add support for verifying v3 signature packets

I have 2 very useful shell scripts related to resizing consoles. The first is imaginatively called resize and just configures the terminal to be the requested size, neatly resizing an xterm or gnome-terminal:

#!/bin/sh
# resize <rows> <columns>
/bin/echo -e '\033[8;'$1';'$2't'

The other is a bit more complicated and useful when connecting to a host via a serial console, or when driving a qemu VM with -display none -nographic and all output coming over a serial console on stdio. It figures out the size of the terminal it s running in and correctly sets the local settings to match so you can take full advantage of a larger terminal than the default 80x24:

#!/bin/bash
echo -ne '\e[s\e[5000;5000H'
IFS='[;' read -p $'\e[6n' -d R -a pos -rs
echo -ne '\e[u'
# cols / rows
echo "Size: $ pos[2]  x $ pos[1] "
stty cols "$ pos[2] " rows "$ pos[1] "
export TERM=xterm-256color

Generally I source this with . fix-term or the TERM export doesn t get applied. Both of these exist in various places around the net (and there s a resize binary shipped along with xterm) but I always forget the exact terms to find it again when I need it. So this post is mostly intended to serve as future reference next time I don t have them handy.

I bought myself a new keyboard last November, a Logitech G213. True keyboard fans will tell me it s not a real mechanical keyboard, but it was a lot cheaper and met my requirements of having some backlighting and a few media keys (really all I use are the volume control keys). Oh, and being a proper UK layout. While the G213 isn t fully independent RGB per key it does have a set of zones that can be controlled. Also this has been reverse engineered, so there are tools to do this under Linux. All I really wanted was some basic backlighting to make things a bit nicer in the evenings, but with the ability to control colour I felt I should put it to good use. As previously mentioned I have a personal desktop / work laptop setup combined with a UGREEN USB 3.0 Sharing Switch Box, so the keyboard is shared between both machines. So I configured up both machines to set the keyboard colour when the USB device is plugged in, and told them to use different colours. Instant visual indication of which machine I m currently typing on! Running the script on USB detection is easy, a file in /etc/udev/rules.d/. I called it 99-keyboard-colour.rules:

# Change the keyboard colour when we see it
ACTION=="add", SUBSYSTEM=="usb", ATTR idVendor =="046d", ATTR idProduct =="c336", \
        RUN+="/usr/local/sbin/g213-set"

g213-set is a simple bit of Python:

#!/usr/bin/python3
import sys
found = False
devnum = 0
while not found:
    try:
        with open("/sys/class/hidraw/hidraw" + str(devnum) + "/device/uevent") as f:
            for line in f:
                line = line.rstrip()
                if line == 'HID_NAME=Logitech Gaming Keyboard G213':
                    found = True
    except:
        break
    if not found:
        devnum += 1
if not found:
    print("Could not find keyboard device")
    sys.exit(1)
eventfile = "/dev/hidraw" + str(devnum)
#                                   z       r     g     b
command = [ 0x11, 0xff, 0x0c, 0x3a, 0, 1, 0xff, 0xff, 0x00, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ]
with open(eventfile, "wb") as f:
    f.write(bytes(command))

I did wonder about trying to make it turn red when I m in a root terminal, but that gets a bit more complicated (I m guessing I need to hook into GNOME Terminal some how?) and this simple hack gives me a significant win anyway.

This has ended up longer than I expected. I ll write up posts about some of the individual steps with some more details at some point, but this is an overview of the yak shaving I engaged in. The TL;DR is:

I wanted to upgrade my internet connection, but:
My router wasn t fast enough, so:
I bought a new one and:
Proceeded to help work on mainline Linux support, and:
Did some tweaking of my Debian setup to allow for a squashfs root, and:
Upgraded it to Debian 11 (bullseye) in the process, except:
It turned out my home automation devices weren t happy, so:
I dug into some memory issues on my ESP8266 firmware, which:
Led to diagnosing some TLS interaction issues with the firmware, and:
I had an interlude into some interrupt affinity issues, but:
I finally got there.

The desire for a faster connection When I migrated my home connection to FTTP I kept the same 80M/20M profile I d had on FTTC. I didn t have a pressing need for faster, and I saved money because I was no longer paying for the phone line portion. I wanted more, but at the time I think the only option was for a 160M/30M profile instead and I didn t need it and it wasn t enough better to convince me. Time passed and BT rolled out their GigE (really 900M) download option. And again, I didn t need it, but I wanted it. My provider, Aquiss, initially didn t offer this (I think they had up to 330M download options available by this point). So I stayed on 80M/20M. And the only time I really wanted it to be faster was when pushing off-site backups to rsync.net. Of course, we ve had the pandemic, and that s involved 2 adults working from home with plenty of video calls throughout the day. The 80M/20M connection has proved rock solid for this, so again, I didn t feel an upgrade was justified. We got a 4K capable TV last year and while the bandwidth usage for 4K streaming is noticeably higher, again the connection can handle it no problem. At some point last year I noticed Aquiss had added speed options all the way to 900M down. At the end of the year I accepted a new role, which is fully remote, so I had a bit of an acceptance about the fact that I wasn t going back into an office any time soon. The combination (and the desire for the increased upload speed) finally allowed me to justify the upgrade to myself.

Testing the current setup for bottlenecks The first thing to do was see whether my internal network could cope with an upgrade. I m mostly running Cat6 GigE so I wasn t worried about that side of things. However I m using an RB3011 as my core router, and while it has some coprocessors for routing acceleration they re not supported under mainline Linux (and unlikely to be any time soon). So I had to benchmark what it was capable of routing. I run a handful of VLANs within my home network, with stateful firewalling between them, so I felt that would be a good approximation of the maximum speed to the outside world I might be able to get if I had the external connection upgraded. I went for the easy approach and fired up iPerf3 on 2 hosts, both connected via ethernet but on separate networks, so routed through the RB3011. That resulted in slightly more than a 300Mb/s throughput. Ok. I confirmed that I could get 900Mb/s+ on 2 hosts both on the same network, just to be sure there wasn t some other issue I was missing. Nope, so unsurprisingly the router was the bottleneck. So. To upgrade my internet speed I need to upgrade my router. I could just buy something off the shelf, but I like being able to run Debian (or OpenWRT) on the router rather than some horrible vendor firmware. Lucky MikroTik launched the RB5009 towards the end of last year. RouterOS is probably more than capable, but what really interested me was the fact it s an ARM64 platform based on an Armada 7040, which is pretty well supported in mainline kernels already. There s a 10G connection from the internal switch to the CPU, as well as a 2.5Gb/s ethernet port and a 10G SFP+ cage. All good stuff. I ordered one just before the New Year. Thankfully the OpenWRT folk had done all of the hard work on getting a mainline kernel booting on the device; Sergey Sergeev and Robert Marko in particular fighting RouterBoot and producing a suitable device tree file to get everything up and running. I ended up soldering a serial console connection up to aid debugging, and lightly patching Rob s u-boot to fix the incorrect RAM size reported by RouterBoot. A few kernel tweaks were necessary to make the networking entirely happy and at that point it was time to think about actually doing a replacement.

Upgrading to Debian 11 (bullseye) My RB3011 is currently running Debian 10 (buster); an upgrade has been on my todo list, but with the impending replacement I decided I d hold off and create a new Debian 11 (bullseye) image for the RB5009. Additionally, I don t actually run off the internal NAND in the RB3011; I have a USB flash drive for the rootfs and just the kernel booting off internal NAND. Originally this was for ease of testing, then a combination of needing to figure out a good read-only root solution and a small enough image to fit in the 120M available. For the upgrade I decided to finally look at these pieces. I ve ended up with a script that will build me a squashfs image, and the initial rootfs takes care of mounting this and then a tmpfs as an overlay fs. That means I can easily see what pieces are being written to. The RB5009 has a total of 1G NAND so I m not as space constrained, but the squashfs ends up under 50M. I ve added some additional pieces to allow me to pre-populate the overlay fs with updates rather than always needing to rebuild the squashfs image. With that done I decided to try it out on the RB3011; I tweaked the build script to be able to build for armhf (the RB3011) or arm64 (the RB5009) and to deal with some slight differences in configuration between the two (e.g. interface naming). The idea here was to ensure I d got all the appropriate configuration sorted for the RB5009, in the known-good existing environment. Everything is still on a USB stick at this stage and the new device has an armhf busybox root meaning it can be used on either device, and the init script detects the architecture to select the appropriate squashfs to mount.

A problem with ESP8266 home automation devices Everything seemed to work fine - a few niggles with the watchdog, which is overly sensitive on the RB3011, but I got those sorted (and the build script updated) and the device came up and successfully did the PPPoE dance to bring up external connectivity. And then I noticed that my home automation devices were having problems connecting to the mosquitto MQTT server. It turned out it was only the ESP8266 based devices that were failing, and examining the serial debug output on one of my test devices revealed it was hitting an out of memory issue (displaying `E:M 280`) when establishing the TLS MQTT connection. I rolled back to the Debian 10 image and set about creating a test environment to look at the ESP8266 issues. My first action was to try and reduce my RAM footprint to try and ensure there was enough spare to establish the connection. I moved a few functions that were still sitting in IRAM into flash. I cleaned up a couple of buffers that are on the stack to be more correctly sized. I tried my new image, and I didn t get the memory issue. Instead I progressed a bit further and got a watchdog reset. Doh! It was obviously something related to the TLS connection, but I couldn t easily see what the difference was; the same x509 cert was in use, it looked like the initial handshake was the same (and trying with `openssl s_client` looked pretty similar too). I set about instrumenting the ancient Mbed TLS used in the Espressif SDK and discovered that whatever had changed between buster + bullseye meant the EPS8266 was now trying a TLS-DHE-RSA-WITH-AES-256-CBC-SHA256 handshake instead of a TLS-RSA-WITH-AES-256-CBC-SHA256 handshake and that was causing enough extra CPU usage that it couldn t complete in time and the watchdog kicked in. So I commented out `MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED` in the `config_esp.h` for mbedtls and rebuilt things. Hacky, but I ll go back to trying to improve this generally at some point.

A detour into interrupt load Now, my testing of the RB3011 image is generally done at weekends, when I have enough time to tear down and rebuild the connection rather than doing it in the evening and having limited time to get things working again in time for work in the morning. So at the point I had an image ready to go I pulled the trigger on the line upgrade. I went with the 500M/75M option rather than the full 900M - I suspect I d have difficulty actually getting that most of the time and 75M of upload bandwidth seems fairly substantial for now. It only took a couple of days from the order to the point the line was regraded (which involved no real downtime - just a reconnection in the night). Of course this happened just after the weekend I d discovered the ESP8266 issue. This provided an opportunity to see just what the RB3011 could actually manage. In the configuration I had it turned out to be not much more than the 80Mb/s speeds I had previously seen. The upload jumped from a solid 20Mb/s to 75Mb/s, so I knew the regrade had actually happened. Looking at CPU utilisation clearly showed the problem; softirqs were using almost 100% of a CPU core. Now, the way the hardware is setup on the RB3011 is that there are two separate 5 port switches, each connected back to the CPU via a separate GigE interface. For various reasons I had everything on a single switch, which meant that all traffic was boomeranging in and out of the same CPU interface. The IPQ8064 has dual cores, so I thought I d try moving the external connection to the other switch. That puts it on its own GigE CPU interface, which then allows binding the interrupts to a different CPU core. That helps; throughput to the outside world hits 140Mb/s+. Still a long way from the expected max, but proof we just need more grunt.

Success Which brings us to this past weekend, when, having worked out all the other bits, I tried the squashfs root image again on the RB3011. Success! The home automation bits connected to it, the link to the outside world came up, everything seemed happy. So I double checked my bootloader bits on the RB5009, brought it down to the comms room and plugged it in instead. And, modulo my failing to update the nftables config to allow it to do forwarding, it all came up ok. Some testing with iperf3 internally got a nice 912Mb/s sustained between subnets, and some less scientific testing with wget + speedtest-cli saw speeds of over 460Mb/s to the outside world. Time from ordering the router until it was in service? Just under 8 weeks

About a month later than I probably should have posted it, here s a recap of my Free Software activities in 2021. For previous years see 2019 + 2020. Again, this year had fewer contributions than I d like thanks to continuing fatigue about the state of the world, and trying to work on separation between work and leisure while working from home. I ve made some effort to improve that balance but it s still a work in progress.

Conferences No surprise, I didn t attend any in-person conferences in 2021. I find virtual conferences don t do a lot for me (a combination of my not carving time out for them in the same way, because not being at the conference means other things will inevitably intrude, and the lack of the social side) but I did get to attend a few of the DebConf21 talks, which was nice. I m hoping to make it to DebConf22 this year in person.

Debian Most of my contributions to Free software continue to happen within Debian. As part of the Data Protection Team I responded to various inbound queries to that team. Some of this involved chasing up other project teams who had been slow to respond - folks, if you re running a service that stores personal data about people then you need to be responsive to requests about it. Some of this was dealing with what look like automated scraping tools which send no information about the person making the request, and in all the cases we ve seen so far there s been no indication of any data about that person on any systems we have access to. Further team time was wasted dealing with the Princeton-Radboud Study on Privacy Law Implementation (though Matthew did the majority of the work on this). The Debian Keyring was possibly my largest single point of contribution. We re in a roughly 3 month rotation of who handles the keyring updates, and I handled 2021.03.24, 2021.04.09, 2021.06.25, 2021.09.25 + 2021.12.24 For Debian New Members I m mostly inactive as an application manager - we generally seem to have enough available recently. If that changes I ll look at stepping in to help, but I don t see that happening. I continue to be involved in Front Desk, having various conversations throughout the year with the rest of the team, but there s no doubt Mattia and Pierre-Elliott are the real doers at present. I did take part in an NM Committee appeals process. In terms of package uploads I continued to work on gcc-xtensa-lx106, largely doing uploads to deal with updates to the GCC version or packaging (8 + 9). sigrok had a few minor updates, libsigkrok 0.5.2-3, pulseview 0.4.2-3 as well as a new upstream release of sigrok CLI 0.7.2-1. There was a last minute pre-release upload of libserialport 0.1.1-4 thanks to a kernel change in v5.10.37 which removed termiox support. Despite still not writing any VHDL these days I continue to keep an eye on ghdl, because I found it a useful tool in the past. Last year that was just a build fix for LLVM 11.1.0 - 1.0.0+dfsg+5. Andreas Bombe has largely taken over more proactive maintenance, which is nice to see. I uploaded OpenOCD 0.11.0~rc1-2, cleaning up some packaging / dependency issues. This was followed by 0.11.0~rc2-1 as a newer release candidate. Sadly 0.11.0 did not make it in time for bullseye, but rc2 was fairly close and I uploaded 0.11.0-1 once bullseye was released. Finally I did a drive-by upload for garmin-forerunner-tools 0.10repacked-12, cleaning up some packaging issues and uploading it to salsa. My Forerunner 305 has died (after 11 years of sterling service) and the Forerunner 45 I ve replaced it with uses a different set of tools, so I decided it didn t make sense to pick up longer term ownership of the package.

Linux My Linux contributions continued to revolve around pushing MikroTik RB3011 support upstream. There was a minor code change to Set FIFO sizes for ipq806x (which fixed up the allowed MTU for the internal switch + VLANs). The rest was DTS related - adding ADM DMA + NAND definitions now that the ADM driver was merged, adding tsens details, adding USB port info and adding the L2CC and RPM details for IPQ8064. Finally I was able to update the RB3011 DTS to enable NAND + USB. With all those in I m down to 4 local patches against a mainline kernel, all of which are hacks that aren t suitable for submission upstream. 2 are for patching in details of the root device and ethernet MAC addresses, one is dealing with the fact the IPQ8064 has some reserved memory that doesn t play well with `AUTO_ZRELADDR` (there keeps being efforts to add some support for this via devicetree, but unfortunately it gets shot down every time), and the final one is a hack to turn off the LCD backlight by treating it as an LED (actually supporting the LCD properly is on my TODO list).

Personal projects 2021 didn t see any releases of onak. It s not dead, just resting, but Sequoia PGP is probably where you should be looking for a modern OpenPGP implementation. I continued work on my Desk Viking project, which is an STM32F103 based debug tool inspired by the Bus Pirate. The main addtion was some CCLib support (forking it in the process to move to Python 3 and add some speed ups) to allow me to program my Zigbee dongles, but I also added some 1-Wire search logic and some support for Linux emulation mode with VCD output to allow for a faster development cycle. I really want to try and get OpenOCD JTAG mode supported at some point, and have vague plans for an STM32F4 based version that have suffered from a combination of a silicon shortage and a lack of time. That wraps up 2021. I d like to say I m hoping to make more Free Software contributions this year, but I don t have a concrete plan yet for how that might happen, so I ll have to wait and see.

Previously I setup a CC2531 as a Zigbee coordinator for my home automation. This has turned out to be a good move, with the 4 gang wireless switch being particularly useful. However the range of the CC2531 is fairly poor; it has a simple PCB antenna. It s also a very basic device. I set about trying to improve the range and scalability and settled upon a CC2538 + CC2592 device, which feature an MMCX antenna connector. This device also has the advantage that it s ARM based, which I m hopeful means I might be able to build some firmware myself using a standard GCC toolchain. For now I fetched the JetHome firmware from https://github.com/jethome-ru/zigbee-firmware/tree/master/ti/coordinator/cc2538_cc2592 (JH_2538_2592_ZNP_UART_20211222.hex) - while it s possible to do USB directly with the CC2538 my board doesn t have those bits so going the external USB UART route is easier. The device had some existing firmware on it, so I needed to erase this to force a drop into the boot loader. That means soldering up the JTAG pins and hooking it up to my Bus Pirate for OpenOCD goodness.

OpenOCD config

source [find interface/buspirate.cfg]
buspirate_port /dev/ttyUSB1
buspirate_mode normal
buspirate_vreg 1
buspirate_pullup 0
transport select jtag
source [find target/cc2538.cfg]

Steps to erase

$ telnet localhost 4444
Trying ::1...
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Open On-Chip Debugger
> mww 0x400D300C 0x7F800
> mww 0x400D3008 0x0205
> shutdown
shutdown command invoked
Connection closed by foreign host.

At that point I can switch to the UART connection (on PA0 + PA1) and flash using cc2538-bsl:

$ git clone https://github.com/JelmerT/cc2538-bsl.git
$ cc2538-bsl/cc2538-bsl.py -p /dev/ttyUSB1 -e -w -v ~/JH_2538_2592_ZNP_UART_20211222.hex
Opening port /dev/ttyUSB1, baud 500000
Reading data from /home/noodles/JH_2538_2592_ZNP_UART_20211222.hex
Firmware file: Intel Hex
Connecting to target...
CC2538 PG2.0: 512KB Flash, 32KB SRAM, CCFG at 0x0027FFD4
Primary IEEE Address: 00:12:4B:00:22:22:22:22
    Performing mass erase
Erasing 524288 bytes starting at address 0x00200000
    Erase done
Writing 524256 bytes starting at address 0x00200000
Write 232 bytes at 0x0027FEF88
    Write done
Verifying by comparing CRC32 calculations.
    Verified (match: 0x74f2b0a1)

I then wanted to migrate from the old device to the new without having to repair everything. So I shut down Home Assistant and backed up the CC2531 network information using zigpy-znp (which is already installed for Home Assistant):

python3 -m zigpy_znp.tools.network_backup /dev/zigbee > cc2531-network.json

I copied the backup to cc2538-network.json and modified the coordinator_ieee to be the new device s MAC address (rather than end up with 2 devices claiming the same MAC if/when I reuse the CC2531) and did:

python3 -m zigpy_znp.tools.network_restore --input cc2538-network.json /dev/ttyUSB1

The old CC2531 needed unplugged first, otherwise I got an

RuntimeError: Network formation refused, RF environment is likely too noisy. Temporarily unscrew the antenna or shield the coordinator with metal until a network is formed.

error. After that I updated my udev rules to map the CC2538 to /dev/zigbee and restarted Home Assistant. To my surprise it came up and detected the existing devices without any extra effort on my part. However that resulted in 2 coordinators being shown in the visualisation, with the old one turning up as unk_manufacturer. Fixing that involved editing /etc/homeassistant/.storage/core.device_registry and removing the entry which had the old MAC address, removing the device entry in /etc/homeassistant/.storage/zha.storage for the old MAC and then finally firing up sqlite to modify the Zigbee database:

$ sqlite3 /etc/homeassistant/zigbee.db
SQLite version 3.34.1 2021-01-20 14:10:07
Enter ".help" for usage hints.
sqlite> DELETE FROM devices_v6 WHERE ieee = '00:12:4b:00:11:11:11:11';
sqlite> DELETE FROM endpoints_v6 WHERE ieee = '00:12:4b:00:11:11:11:11';
sqlite> DELETE FROM in_clusters_v6 WHERE ieee = '00:12:4b:00:11:11:11:11';
sqlite> DELETE FROM neighbors_v6 WHERE ieee = '00:12:4b:00:11:11:11:11' OR device_ieee = '00:12:4b:00:11:11:11:11';
sqlite> DELETE FROM node_descriptors_v6 WHERE ieee = '00:12:4b:00:11:11:11:11';
sqlite> DELETE FROM out_clusters_v6 WHERE ieee = '00:12:4b:00:11:11:11:11';
sqlite> .quit

So far it all seems a bit happier than with the CC2531; I ve been able to pair a light bulb that was previously detected but would not integrate, which suggests the range is improved. (This post another in the set of things I should write down so I can just grep my own website when I forget what I did to do foo .)

It s been over 20 months since the first COVID lockdown kicked in here in Northern Ireland and I started working from home. Even when the strict lockdown was lifted the advice here has continued to be If you can work from home you should work from home . I ve been into the office here and there (for new starts given you need to hand over a laptop and sort out some login details it s generally easier to do so in person, and I ve had a couple of whiteboard sessions that needed the high bandwidth face to face communication), but day to day is all from home. Early on I commented that work had taken over my study. This has largely continued to be true. I set my work laptop on the stand on a Monday morning and it sits there until Friday evening, when it gets switched for the personal laptop. I have a lovely LG 34UM88 21:9 Ultrawide monitor, and my laptops are small and light so I much prefer to use them docked. Also my general working pattern is to have a lot of external connections up and running (build machine, test devices, log host) which means a suspend/resume cycle disrupts things. So I like to minimise moving things about. I spent a little bit of time trying to find a dual laptop stand so I could have both machines setup and switch between them easily, but I didn t find anything that didn t seem to be geared up for DJs with a mixer + laptop combo taking up quite a bit of desk space rather than stacking laptops vertically. Eventually I realised that the right move was probably a desktop machine. Now, I haven t had a desktop machine since before I moved to the US, realising at the time that having everything on my laptop was much more convenient. I decided I didn t want something too big and noisy. Cheap GPUs seem hard to get hold of these days - I m not a gamer so all I need is something that can drive a ~ 4K monitor reliably enough. Looking around the AMD Ryzen 7 5700G seemed to be a decent CPU with one of the better integrated GPUs. I spent some time looking for a reasonable Mini-ITX case + motherboard and then I happened upon the ASRock DeskMini X300. This turns out to be perfect; I ve no need for a PCIe slot or anything more than an m.2 SSD. I paired it with a Noctua NH-L9a-AM4 heatsink + fan (same as I use in the house server), 32GB DDR4 and a 1TB WD SN550 NVMe SSD. Total cost just under 650 inc VAT + delivery (and that s a story for another post). A desktop solves the problem of fitting both machines on the desk at once, but there s still the question of smoothly switching between them. I read Evgeni Golov s article on a simple KVM switch for 30. My monitor has multiple inputs, so that s sorted. I did have a cheap USB2 switch (all I need for the keyboard/trackball) but it turned out to be pretty unreliable at the host detecting the USB change. I bought a UGREEN USB 3.0 Sharing Switch Box instead and it s turned out to be pretty reliable. The problem is that the LG 32UM88 turns out to have a poor DDC implementation, so while I can flip the keyboard easily with the UGREEN box I also have to manually select the monitor input. Which is a bit annoying, but not terrible. The important question is whether this has helped. I built all this at the end of October, so I ve had a month to play with it. Turns out I should have done it at some point last year. At the end of the day instead of either sitting at work for a bit longer, or completely avoiding the study, I m able to lock the work machine and flick to my personal setup. Even sitting in the same seat that disconnect , and the knowledge I won t see work Slack messages or emails come in and feeling I should respond, really helps. It also means I have access to my personal setup during the week without incurring a hit at the start of the working day when I have to set things up again. So it s much easier to just dip in to some personal tech stuff in the evening than it was previously. Also from the point of view I don t need to setup the personal config, I can pick up where I left off. All of which is really nice. It s also got me thinking about other minor improvements I should make to my home working environment to try and improve things. One obvious thing now the winter is here again is to improve my lighting; I have a good overhead LED panel but it s terribly positioned for video calls, being just behind me. So I think I m looking some sort of strip light I can have behind the large monitor to give a decent degree of backlight (possibly bouncing off the white wall). Lots of cheap options I m not convinced about, and I ve had a few ridiculously priced options from photographer friends; suggestions welcome.

My home automation setup has been fairly static recently; it does what we need and generally works fine. One area I think could be better is controlling it; we have access Home Assistant on our phones, and the Alexa downstairs can control things, but there are no smart assistants upstairs and sometimes it would be nice to just push a button to turn on the light rather than having to get my phone out. Thanks to the fact the UK generally doesn t have neutral wire in wall switches that means looking at something battery powered. Which means wifi based devices are a poor choice, and it s necessary to look at something lower power like Zigbee or Z-Wave. Zigbee seems like the better choice; it s a more open standard and there are generally more devices easily available from what I ve seen (e.g. Philips Hue and IKEA TR DFRI). So I bought a couple of Xiaomi Mi Smart Home Wireless Switches, and a CC2530 module and then ignored it for the best part of a year. Finally I got around to flashing the Z-Stack firmware that Koen Kanters kindly provides. (Insert rant about hardware manufacturers that require pay-for tool chains. The CC2530 is even worse because it s 8051 based, so SDCC should be able to compile for it, but the TI Zigbee libraries are only available in a format suitable for IAR s embedded workbench.) Flashing the CC2530 is a bit of faff. I ended up using the CCLib fork by Stephan Hadinger which supports the ESP8266. The nice thing about the CC2530 module is it has 2.54mm pitch pins so nice and easy to jumper up. It then needs a USB/serial dongle to connect it up to a suitable machine, where I ran Zigbee2MQTT. This scares me a bit, because it s a bunch of node.js pulling in a chunk of stuff off npm. On the flip side, it Just Works and I was able to pair the Xiaomi button with the device and see MQTT messages that I could then use with Home Assistant. So of course I tore down that setup and went and ordered a CC2531 (the variant with USB as part of the chip). The idea here was my test setup was upstairs with my laptop, and I wanted something hooked up in a more permanent fashion. Once the CC2531 arrived I got distracted writing support for the Desk Viking to support CCLib (and modified it a bit for Python3 and some speed ups). I flashed the dongle up with the Z-Stack Home 1.2 (default) firmware, and plugged it into the house server. At this point I more closely investigated what Home Assistant had to offer in terms of Zigbee integration. It turns out the ZHA integration has support for the ZNP protocol that the TI devices speak (I m reasonably sure it didn t when I first looked some time ago), so that seemed like a better option than adding the MQTT layer in the middle. I hit some complexity passing the dongle (which turns up as /dev/ttyACM0) through to the Home Assistant container. First I needed an override file in /etc/systemd/nspawn/hass.nspawn:

[Files]
Bind=/dev/ttyACM0:/dev/zigbee
[Network]
VirtualEthernet=true

(I m not clear why the VirtualEthernet needed to exist; without it networking broke entirely but I couldn t see why it worked with no override file.) A udev rule on the host to change the ownership of the device file so the root user and dialout group in the container could see it was also necessary, so into /etc/udev/rules.d/70-persistent-serial.rules went:

# Zigbee for HASS
SUBSYSTEM=="tty", ATTRS idVendor =="0451", ATTRS idProduct =="16a8", SYMLINK+="zigbee", \
	MODE="660", OWNER="1321926676", GROUP="1321926676"

In the container itself I had to switch PrivateDevices=true to PrivateDevices=false in the home-assistant.service file (which took me a while to figure out; yay for locking things down and then needing to use those locked down things). Finally I added the hass user to the dialout group. At that point I was able to go and add the integration with Home Assistant, and add the button as a new device. Excellent. I did find I needed a newer version of Home Assistant to get support for the button, however. I was still on 2021.1.5 due to upstream dropping support for Python 3.7 and not being prepared to upgrade to Debian 11 until it was actually released, so the version of zha-quirks didn t have the correct info. Upgrading to Home Assistant 2021.8.7 sorted that out. There was another slight problem. Range. Really I want to use the button upstairs. The server is downstairs, and most of my internal walls are brick. The solution turned out to be a TR DFRI socket, which replaced the existing ESP8266 wifi socket controlling the stair lights. That was close enough to the server to have a decent signal, and it acts as a Zigbee router so provides a strong enough signal for devices upstairs. The normal approach seems to be to have a lot of Zigbee light bulbs, but I have mostly kept overhead lights as uncontrolled - we don t use them day to day and it provides a nice fallback if the home automation has issues. Of course installing Zigbee for a single button would seem to be a bit pointless. So I ordered up a Sonoff door sensor to put on the front door (much smaller than expected - those white boxes on the door are it in the picture above). And I have a 4 gang wireless switch ordered to go on the landing wall upstairs. Now I ve got a Zigbee setup there are a few more things I m thinking of adding, where wifi isn t an option due to the need for battery operation (monitoring the external gas meter springs to mind). The CC2530 probably isn t suitable for my needs, as I ll need to write some custom code to handle the bits I want, but there do seem to be some ARM based devices which might well prove suitable

Having build a single node Kubernetes cluster and had a poke at what it s doing in terms of networking the next thing I want to do is figure out what it s doing in terms of containers. You might argue this should have come before networking, but to me the networking piece is more non-standard than the container piece, so I wanted to understand that first. Let s start with a process listing on the host. ps faxno user,stat,cmd There are a number of processes from the host kernel we don t care about:

kernel processes

    USER STAT CMD
       0 S    [kthreadd]
       0 I<    \_ [rcu_gp]
       0 I<    \_ [rcu_par_gp]
       0 I<    \_ [kworker/0:0H-events_highpri]
       0 I<    \_ [mm_percpu_wq]
       0 S     \_ [rcu_tasks_rude_]
       0 S     \_ [rcu_tasks_trace]
       0 S     \_ [ksoftirqd/0]
       0 I     \_ [rcu_sched]
       0 S     \_ [migration/0]
       0 S     \_ [cpuhp/0]
       0 S     \_ [cpuhp/1]
       0 S     \_ [migration/1]
       0 S     \_ [ksoftirqd/1]
       0 I<    \_ [kworker/1:0H-kblockd]
       0 S     \_ [cpuhp/2]
       0 S     \_ [migration/2]
       0 S     \_ [ksoftirqd/2]
       0 I<    \_ [kworker/2:0H-events_highpri]
       0 S     \_ [cpuhp/3]
       0 S     \_ [migration/3]
       0 S     \_ [ksoftirqd/3]
       0 I<    \_ [kworker/3:0H-kblockd]
       0 S     \_ [kdevtmpfs]
       0 I<    \_ [netns]
       0 S     \_ [kauditd]
       0 S     \_ [khungtaskd]
       0 S     \_ [oom_reaper]
       0 I<    \_ [writeback]
       0 S     \_ [kcompactd0]
       0 SN    \_ [ksmd]
       0 SN    \_ [khugepaged]
       0 I<    \_ [kintegrityd]
       0 I<    \_ [kblockd]
       0 I<    \_ [blkcg_punt_bio]
       0 I<    \_ [edac-poller]
       0 I<    \_ [devfreq_wq]
       0 I<    \_ [kworker/0:1H-kblockd]
       0 S     \_ [kswapd0]
       0 I<    \_ [kthrotld]
       0 I<    \_ [acpi_thermal_pm]
       0 I<    \_ [ipv6_addrconf]
       0 I<    \_ [kstrp]
       0 I<    \_ [zswap-shrink]
       0 I<    \_ [kworker/u9:0-hci0]
       0 I<    \_ [kworker/2:1H-kblockd]
       0 I<    \_ [ata_sff]
       0 I<    \_ [sdhci]
       0 S     \_ [irq/39-mmc0]
       0 I<    \_ [sdhci]
       0 S     \_ [irq/42-mmc1]
       0 S     \_ [scsi_eh_0]
       0 I<    \_ [scsi_tmf_0]
       0 S     \_ [scsi_eh_1]
       0 I<    \_ [scsi_tmf_1]
       0 I<    \_ [kworker/1:1H-kblockd]
       0 I<    \_ [kworker/3:1H-kblockd]
       0 S     \_ [jbd2/sda5-8]
       0 I<    \_ [ext4-rsv-conver]
       0 S     \_ [watchdogd]
       0 S     \_ [scsi_eh_2]
       0 I<    \_ [scsi_tmf_2]
       0 S     \_ [usb-storage]
       0 I<    \_ [cfg80211]
       0 S     \_ [irq/130-mei_me]
       0 I<    \_ [cryptd]
       0 I<    \_ [uas]
       0 S     \_ [irq/131-iwlwifi]
       0 S     \_ [card0-crtc0]
       0 S     \_ [card0-crtc1]
       0 S     \_ [card0-crtc2]
       0 I<    \_ [kworker/u9:2-hci0]
       0 I     \_ [kworker/3:0-events]
       0 I     \_ [kworker/2:0-events]
       0 I     \_ [kworker/1:0-events_power_efficient]
       0 I     \_ [kworker/3:2-events]
       0 I     \_ [kworker/1:1]
       0 I     \_ [kworker/u8:1-events_unbound]
       0 I     \_ [kworker/0:2-events]
       0 I     \_ [kworker/2:2]
       0 I     \_ [kworker/u8:0-events_unbound]
       0 I     \_ [kworker/0:1-events]
       0 I     \_ [kworker/0:0-events]

There are various basic host processes, including my SSH connections, and Docker. I note it s using containerd. We also see kubelet, the Kubernetes node agent.

host processes

    USER STAT CMD
       0 Ss   /sbin/init
       0 Ss   /lib/systemd/systemd-journald
       0 Ss   /lib/systemd/systemd-udevd
     101 Ssl  /lib/systemd/systemd-timesyncd
       0 Ssl  /sbin/dhclient -4 -v -i -pf /run/dhclient.enx00e04c6851de.pid -lf /var/lib/dhcp/dhclient.enx00e04c6851de.leases -I -df /var/lib/dhcp/dhclient6.enx00e04c6851de.leases enx00e04c6851de
       0 Ss   /usr/sbin/cron -f
     104 Ss   /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
       0 Ssl  /usr/sbin/dockerd -H fd://
       0 Ssl  /usr/sbin/rsyslogd -n -iNONE
       0 Ss   /usr/sbin/smartd -n
       0 Ss   /lib/systemd/systemd-logind
       0 Ssl  /usr/bin/containerd
       0 Ss+  /sbin/agetty -o -p -- \u --noclear tty1 linux
       0 Ss   sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startups
       0 Ss    \_ sshd: root@pts/1
       0 Ss        \_ -bash
       0 R+            \_ ps faxno user,stat,cmd
       0 Ss    \_ sshd: noodles [priv]
    1000 S         \_ sshd: noodles@pts/0
    1000 Ss+           \_ -bash
       0 Ss   /lib/systemd/systemd --user
       0 S     \_ (sd-pam)
    1000 Ss   /lib/systemd/systemd --user
    1000 S     \_ (sd-pam)
       0 Ssl  /usr/bin/kubelet --bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf --config=/var/lib/kubelet/config.yaml --network-plugin=cni --pod-infra-container-image=k8s.gcr.io/pause:3.4.1

And that just leaves a bunch of container related processes:

container processes

       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id fd95c597ff3171ff110b7bf440229e76c5108d5d93be75ffeab54869df734413 -address /run/containerd/containerd.sock
       0 Ss    \_ /pause
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id c2ff2c50f0bc052feda2281741c4f37df7905e3b819294ec645148ae13c3fe1b -address /run/containerd/containerd.sock
       0 Ss    \_ /pause
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 589c1545d9e0cdf8ea391745c54c8f4db49f5f437b1a2e448e7744b2c12f8856 -address /run/containerd/containerd.sock
       0 Ss    \_ /pause
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 6f417fd8a8c573a2b8f792af08cdcd7ce663457f0f7218c8d55afa3732e6ee94 -address /run/containerd/containerd.sock
       0 Ss    \_ /pause
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id afa9798c9f663b21df8f38d9634469e6b4db0984124547cd472a7789c61ef752 -address /run/containerd/containerd.sock
       0 Ssl   \_ kube-scheduler --authentication-kubeconfig=/etc/kubernetes/scheduler.conf --authorization-kubeconfig=/etc/kubernetes/scheduler.conf --bind-address=127.0.0.1 --kubeconfig=/etc/kubernetes/scheduler.conf --leader-elect=true --port=0
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 4b3708b62f4d427690f5979848c59fce522dab6c62a9c53b806ffbaef3f88e62 -address /run/containerd/containerd.sock
       0 Ssl   \_ kube-controller-manager --authentication-kubeconfig=/etc/kubernetes/controller-manager.conf --authorization-kubeconfig=/etc/kubernetes/controller-manager.conf --bind-address=127.0.0.1 --client-ca-file=/etc/kubernetes/pki/ca.crt --cluster-name=kubernetes --cluster-signing-cert-file=/etc/kubernetes/pki/ca.crt --cluster-signing-key-file=/etc/kubernetes/pki/ca.key --controllers=*,bootstrapsigner,tokencleaner --kubeconfig=/etc/kubernetes/controller-manager.conf --leader-elect=true --port=0 --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt --root-ca-file=/etc/kubernetes/pki/ca.crt --service-account-private-key-file=/etc/kubernetes/pki/sa.key --use-service-account-credentials=true
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 89f35bf7a825eb97db7035d29aa475a3a1c8aaccda0860a46388a3a923cd10bc -address /run/containerd/containerd.sock
       0 Ssl   \_ kube-apiserver --advertise-address=192.168.53.147 --allow-privileged=true --authorization-mode=Node,RBAC --client-ca-file=/etc/kubernetes/pki/ca.crt --enable-admission-plugins=NodeRestriction --enable-bootstrap-token-auth=true --etcd-cafile=/etc/kubernetes/pki/etcd/ca.crt --etcd-certfile=/etc/kubernetes/pki/apiserver-etcd-client.crt --etcd-keyfile=/etc/kubernetes/pki/apiserver-etcd-client.key --etcd-servers=https://127.0.0.1:2379 --insecure-port=0 --kubelet-client-certificate=/etc/kubernetes/pki/apiserver-kubelet-client.crt --kubelet-client-key=/etc/kubernetes/pki/apiserver-kubelet-client.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --proxy-client-cert-file=/etc/kubernetes/pki/front-proxy-client.crt --proxy-client-key-file=/etc/kubernetes/pki/front-proxy-client.key --requestheader-allowed-names=front-proxy-client --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/etc/kubernetes/pki/sa.pub --service-account-signing-key-file=/etc/kubernetes/pki/sa.key --service-cluster-ip-range=10.96.0.0/12 --tls-cert-file=/etc/kubernetes/pki/apiserver.crt --tls-private-key-file=/etc/kubernetes/pki/apiserver.key
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 2dabff6e4f59c96d931d95781d28314065b46d0e6f07f8c65dc52aa465f69456 -address /run/containerd/containerd.sock
       0 Ssl   \_ etcd --advertise-client-urls=https://192.168.53.147:2379 --cert-file=/etc/kubernetes/pki/etcd/server.crt --client-cert-auth=true --data-dir=/var/lib/etcd --initial-advertise-peer-urls=https://192.168.53.147:2380 --initial-cluster=udon=https://192.168.53.147:2380 --key-file=/etc/kubernetes/pki/etcd/server.key --listen-client-urls=https://127.0.0.1:2379,https://192.168.53.147:2379 --listen-metrics-urls=http://127.0.0.1:2381 --listen-peer-urls=https://192.168.53.147:2380 --name=udon --peer-cert-file=/etc/kubernetes/pki/etcd/peer.crt --peer-client-cert-auth=true --peer-key-file=/etc/kubernetes/pki/etcd/peer.key --peer-trusted-ca-file=/etc/kubernetes/pki/etcd/ca.crt --snapshot-count=10000 --trusted-ca-file=/etc/kubernetes/pki/etcd/ca.crt
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 73fae81715b670255b66419a7959798b287be7bbb41e96f8b711fa529aa02f0d -address /run/containerd/containerd.sock
       0 Ss    \_ /pause
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 26d92a720c560caaa5f8a0217bc98e486b1c032af6c7c5d75df508021d462878 -address /run/containerd/containerd.sock
       0 Ssl   \_ /usr/local/bin/kube-proxy --config=/var/lib/kube-proxy/config.conf --hostname-override=udon
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 7104f65b5d92a56a2df93514ed0a78cfd1090ca47b6ce4e0badc43be6c6c538e -address /run/containerd/containerd.sock
       0 Ss    \_ /pause
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 48d735f7f44e3944851563f03f32c60811f81409e7378641404035dffd8c1eb4 -address /run/containerd/containerd.sock
       0 Ssl   \_ /usr/bin/weave-npc
       0 S<        \_ /usr/sbin/ulogd -v
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 36b418e69ae7076fe5a44d16cef223d8908016474cb65910f2fd54cca470566b -address /run/containerd/containerd.sock
       0 Ss    \_ /bin/sh /home/weave/launch.sh
       0 Sl        \_ /home/weave/weaver --port=6783 --datapath=datapath --name=12:82:8f:ed:c7:bf --http-addr=127.0.0.1:6784 --metrics-addr=0.0.0.0:6782 --docker-api= --no-dns --db-prefix=/weavedb/weave-net --ipalloc-range=192.168.0.0/24 --nickname=udon --ipalloc-init consensus=0 --conn-limit=200 --expect-npc --no-masq-local
       0 Sl        \_ /home/weave/kube-utils -run-reclaim-daemon -node-name=udon -peer-name=12:82:8f:ed:c7:bf -log-level=debug
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 534c0a698478599277482d97a137fab8ef4d62db8a8a5cf011b4bead28246f70 -address /run/containerd/containerd.sock
       0 Ss    \_ /pause
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 9ffd6b668ddfbf3c64c6783bc6f4f6cc9e92bfb16c83fb214c2cbb4044993bf0 -address /run/containerd/containerd.sock
       0 Ss    \_ /pause
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 4a30785f91873a7e6a191e86928a789760a054e4fa6dcd7048a059b42cf19edf -address /run/containerd/containerd.sock
       0 Ssl   \_ /coredns -conf /etc/coredns/Corefile
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 649a507d45831aca1de5231b49afc8ff37d90add813e7ecd451d12eedd785b0c -address /run/containerd/containerd.sock
       0 Ssl   \_ /coredns -conf /etc/coredns/Corefile
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 62b369de8d8cece4d33ec9fda4d23a9718379a8df8b30173d68f20bff830fed2 -address /run/containerd/containerd.sock
       0 Ss    \_ /pause
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 7cbb177bee18dbdeed21fb90e74378e2081436ad5bf116b36ad5077fe382df30 -address /run/containerd/containerd.sock
       0 Ss    \_ /bin/bash /usr/local/bin/run.sh
       0 S         \_ nginx: master process nginx -g daemon off;
   65534 S             \_ nginx: worker process
       0 Ss   /lib/systemd/systemd --user
       0 S     \_ (sd-pam)
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id 6669168db70db4e6c741e8a047942af06dd745fae4d594291d1d6e1077b05082 -address /run/containerd/containerd.sock
       0 Ss    \_ /pause
       0 Sl   /usr/bin/containerd-shim-runc-v2 -namespace moby -id d5fa78fa31f11a4c5fb9fd2e853a00f0e60e414a7bce2e0d8fcd1f6ab2b30074 -address /run/containerd/containerd.sock
     101 Ss    \_ /usr/bin/dumb-init -- /nginx-ingress-controller --publish-service=ingress-nginx/ingress-nginx-controller --election-id=ingress-controller-leader --ingress-class=nginx --configmap=ingress-nginx/ingress-nginx-controller --validating-webhook=:8443 --validating-webhook-certificate=/usr/local/certificates/cert --validating-webhook-key=/usr/local/certificates/key
     101 Ssl       \_ /nginx-ingress-controller --publish-service=ingress-nginx/ingress-nginx-controller --election-id=ingress-controller-leader --ingress-class=nginx --configmap=ingress-nginx/ingress-nginx-controller --validating-webhook=:8443 --validating-webhook-certificate=/usr/local/certificates/cert --validating-webhook-key=/usr/local/certificates/key
     101 S             \_ nginx: master process /usr/local/nginx/sbin/nginx -c /etc/nginx/nginx.conf
     101 Sl                \_ nginx: worker process
     101 Sl                \_ nginx: worker process
     101 Sl                \_ nginx: worker process
     101 Sl                \_ nginx: worker process
     101 S                 \_ nginx: cache manager process

There s a lot going on there. Some bits are obvious; we can see the nginx ingress controller, our echoserver (the other nginx process hanging off /usr/local/bin/run.sh), and some things that look related to weave. The rest appears to be Kubernete s related infrastructure. kube-scheduler, kube-controller-manager, kube-apiserver, kube-proxy all look like core Kubernetes bits. etcd is a distributed, reliable key-value store. coredns is a DNS server, with plugins for Kubernetes and etcd. What does Docker claim is happening?

docker ps

CONTAINER ID   IMAGE                                 COMMAND                  CREATED      STATUS      PORTS     NAMES
d5fa78fa31f1   k8s.gcr.io/ingress-nginx/controller   "/usr/bin/dumb-init  "   3 days ago   Up 3 days             k8s_controller_ingress-nginx-controller-5b74bc9868-bczdr_ingress-nginx_4d7d3d81-a769-4de9-a4fb-04763b7c1605_0
6669168db70d   k8s.gcr.io/pause:3.4.1                "/pause"                 3 days ago   Up 3 days             k8s_POD_ingress-nginx-controller-5b74bc9868-bczdr_ingress-nginx_4d7d3d81-a769-4de9-a4fb-04763b7c1605_0
7cbb177bee18   k8s.gcr.io/echoserver                 "/usr/local/bin/run. "   3 days ago   Up 3 days             k8s_echoserver_hello-node-59bffcc9fd-8hkgb_default_c7111c9e-7131-40e0-876d-be89d5ca1812_0
62b369de8d8c   k8s.gcr.io/pause:3.4.1                "/pause"                 3 days ago   Up 3 days             k8s_POD_hello-node-59bffcc9fd-8hkgb_default_c7111c9e-7131-40e0-876d-be89d5ca1812_0
649a507d4583   296a6d5035e2                          "/coredns -conf /etc "   4 days ago   Up 4 days             k8s_coredns_coredns-558bd4d5db-flrfq_kube-system_f8b2b52e-6673-4966-82b1-3fbe052a0297_0
4a30785f9187   296a6d5035e2                          "/coredns -conf /etc "   4 days ago   Up 4 days             k8s_coredns_coredns-558bd4d5db-4nvrg_kube-system_1976f4d6-647c-45ca-b268-95f071f064d5_0
9ffd6b668ddf   k8s.gcr.io/pause:3.4.1                "/pause"                 4 days ago   Up 4 days             k8s_POD_coredns-558bd4d5db-flrfq_kube-system_f8b2b52e-6673-4966-82b1-3fbe052a0297_0
534c0a698478   k8s.gcr.io/pause:3.4.1                "/pause"                 4 days ago   Up 4 days             k8s_POD_coredns-558bd4d5db-4nvrg_kube-system_1976f4d6-647c-45ca-b268-95f071f064d5_0
36b418e69ae7   df29c0a4002c                          "/home/weave/launch. "   4 days ago   Up 4 days             k8s_weave_weave-net-mchmg_kube-system_b9af9615-8cde-4a18-8555-6da1f51b7136_1
48d735f7f44e   weaveworks/weave-npc                  "/usr/bin/launch.sh"     4 days ago   Up 4 days             k8s_weave-npc_weave-net-mchmg_kube-system_b9af9615-8cde-4a18-8555-6da1f51b7136_0
7104f65b5d92   k8s.gcr.io/pause:3.4.1                "/pause"                 4 days ago   Up 4 days             k8s_POD_weave-net-mchmg_kube-system_b9af9615-8cde-4a18-8555-6da1f51b7136_0
26d92a720c56   4359e752b596                          "/usr/local/bin/kube "   4 days ago   Up 4 days             k8s_kube-proxy_kube-proxy-6d8kg_kube-system_8bf2d7ec-4850-427f-860f-465a9ff84841_0
73fae81715b6   k8s.gcr.io/pause:3.4.1                "/pause"                 4 days ago   Up 4 days             k8s_POD_kube-proxy-6d8kg_kube-system_8bf2d7ec-4850-427f-860f-465a9ff84841_0
89f35bf7a825   771ffcf9ca63                          "kube-apiserver --ad "   4 days ago   Up 4 days             k8s_kube-apiserver_kube-apiserver-udon_kube-system_1af8c5f362b7b02269f4d244cb0e6fbf_0
afa9798c9f66   a4183b88f6e6                          "kube-scheduler --au "   4 days ago   Up 4 days             k8s_kube-scheduler_kube-scheduler-udon_kube-system_629dc49dfd9f7446eb681f1dcffe6d74_0
2dabff6e4f59   0369cf4303ff                          "etcd --advertise-cl "   4 days ago   Up 4 days             k8s_etcd_etcd-udon_kube-system_c2a3008c1d9895f171cd394e38656ea0_0
4b3708b62f4d   e16544fd47b0                          "kube-controller-man "   4 days ago   Up 4 days             k8s_kube-controller-manager_kube-controller-manager-udon_kube-system_1d1b9018c3c6e7aa2e803c6e9ccd2eab_0
fd95c597ff31   k8s.gcr.io/pause:3.4.1                "/pause"                 4 days ago   Up 4 days             k8s_POD_kube-scheduler-udon_kube-system_629dc49dfd9f7446eb681f1dcffe6d74_0
589c1545d9e0   k8s.gcr.io/pause:3.4.1                "/pause"                 4 days ago   Up 4 days             k8s_POD_kube-controller-manager-udon_kube-system_1d1b9018c3c6e7aa2e803c6e9ccd2eab_0
6f417fd8a8c5   k8s.gcr.io/pause:3.4.1                "/pause"                 4 days ago   Up 4 days             k8s_POD_kube-apiserver-udon_kube-system_1af8c5f362b7b02269f4d244cb0e6fbf_0
c2ff2c50f0bc   k8s.gcr.io/pause:3.4.1                "/pause"                 4 days ago   Up 4 days             k8s_POD_etcd-udon_kube-system_c2a3008c1d9895f171cd394e38656ea0_0

Ok, that s interesting. Before we dig into it, what does Kubernetes say? (I ve trimmed the RESTARTS + AGE columns to make things fit a bit better here; they weren t interesting).

noodles@udon:~$ kubectl get pods --all-namespaces
NAMESPACE       NAME                                        READY   STATUS
default         hello-node-59bffcc9fd-8hkgb                 1/1     Running
ingress-nginx   ingress-nginx-admission-create-8jgkt        0/1     Completed
ingress-nginx   ingress-nginx-admission-patch-jdq4t         0/1     Completed
ingress-nginx   ingress-nginx-controller-5b74bc9868-bczdr   1/1     Running
kube-system     coredns-558bd4d5db-4nvrg                    1/1     Running
kube-system     coredns-558bd4d5db-flrfq                    1/1     Running
kube-system     etcd-udon                                   1/1     Running
kube-system     kube-apiserver-udon                         1/1     Running
kube-system     kube-controller-manager-udon                1/1     Running
kube-system     kube-proxy-6d8kg                            1/1     Running
kube-system     kube-scheduler-udon                         1/1     Running
kube-system     weave-net-mchmg                             2/2     Running

So there are a lot more Docker instances running than Kubernetes pods. What s happening there? Well, it turns out that Kubernetes builds pods from multiple different Docker instances. If you think of a traditional container as being comprised of a set of namespaces (process, network, hostname etc) and a cgroup then a pod is made up of the namespaces and then each docker instance within that pod has it s own cgroup. Ian Lewis has a much deeper discussion in What are Kubernetes Pods Anyway?, but my takeaway is that a pod is a set of sort-of containers that are coupled. We can see this more clearly if we ask systemd for the cgroup breakdown:

systemd-cgls

Control group /:
-.slice
 user.slice 
   user-0.slice 
     session-29.scope 
        515899 sshd: root@pts/1
        515913 -bash
       3519743 systemd-cgls
       3519744 cat
     user@0.service  
       init.scope 
         515902 /lib/systemd/systemd --user
         515903 (sd-pam)
   user-1000.slice 
     user@1000.service  
       init.scope 
         2564011 /lib/systemd/systemd --user
         2564012 (sd-pam)
     session-110.scope 
       2564007 sshd: noodles [priv]
       2564040 sshd: noodles@pts/0
       2564041 -bash
 init.scope 
   1 /sbin/init
 system.slice 
   containerd.service  
       21383 /usr/bin/containerd-shim-runc-v2 -namespace moby -id fd95c597ff31 
       21408 /usr/bin/containerd-shim-runc-v2 -namespace moby -id c2ff2c50f0bc 
       21432 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 589c1545d9e0 
       21459 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 6f417fd8a8c5 
       21582 /usr/bin/containerd-shim-runc-v2 -namespace moby -id afa9798c9f66 
       21607 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 4b3708b62f4d 
       21640 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 89f35bf7a825 
       21648 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 2dabff6e4f59 
       22343 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 73fae81715b6 
       22391 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 26d92a720c56 
       26992 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 7104f65b5d92 
       27405 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 48d735f7f44e 
       27531 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 36b418e69ae7 
       27941 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 534c0a698478 
       27960 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 9ffd6b668ddf 
       28131 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 4a30785f9187 
       28159 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 649a507d4583 
      514667 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 62b369de8d8c 
      514976 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 7cbb177bee18 
      698904 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 6669168db70d 
      699284 /usr/bin/containerd-shim-runc-v2 -namespace moby -id d5fa78fa31f1 
     2805479 /usr/bin/containerd
   systemd-udevd.service 
     2805502 /lib/systemd/systemd-udevd
   cron.service 
     2805474 /usr/sbin/cron -f
   docker.service  
     528 /usr/sbin/dockerd -H fd://
   kubelet.service 
     2805501 /usr/bin/kubelet --bootstrap-kubeconfig=/etc/kubernetes/bootstrap 
   systemd-journald.service 
     2805505 /lib/systemd/systemd-journald
   ssh.service 
     2805500 sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startups
   ifup@enx00e04c6851de.service 
     2805675 /sbin/dhclient -4 -v -i -pf /run/dhclient.enx00e04c6851de.pid -lf 
   rsyslog.service 
     2805488 /usr/sbin/rsyslogd -n -iNONE
   smartmontools.service 
     2805499 /usr/sbin/smartd -n
   dbus.service 
     527 /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile 
   systemd-timesyncd.service 
     2805513 /lib/systemd/systemd-timesyncd
   system-getty.slice 
     getty@tty1.service 
       536 /sbin/agetty -o -p -- \u --noclear tty1 linux
   systemd-logind.service 
     533 /lib/systemd/systemd-logind
 kubepods.slice 
   kubepods-burstable.slice 
     kubepods-burstable-pod1af8c5f362b7b02269f4d244cb0e6fbf.slice 
       docker-6f417fd8a8c573a2b8f792af08cdcd7ce663457f0f7218c8d55afa3732e6ee94.scope  
         21493 /pause
       docker-89f35bf7a825eb97db7035d29aa475a3a1c8aaccda0860a46388a3a923cd10bc.scope  
         21699 kube-apiserver --advertise-address=192.168.33.147 --allow-privi 
     kubepods-burstable-podf8b2b52e_6673_4966_82b1_3fbe052a0297.slice 
       docker-649a507d45831aca1de5231b49afc8ff37d90add813e7ecd451d12eedd785b0c.scope  
         28187 /coredns -conf /etc/coredns/Corefile
       docker-9ffd6b668ddfbf3c64c6783bc6f4f6cc9e92bfb16c83fb214c2cbb4044993bf0.scope  
         27987 /pause
     kubepods-burstable-podc2a3008c1d9895f171cd394e38656ea0.slice 
       docker-c2ff2c50f0bc052feda2281741c4f37df7905e3b819294ec645148ae13c3fe1b.scope  
         21481 /pause
       docker-2dabff6e4f59c96d931d95781d28314065b46d0e6f07f8c65dc52aa465f69456.scope  
         21701 etcd --advertise-client-urls=https://192.168.33.147:2379 --cert 
     kubepods-burstable-pod629dc49dfd9f7446eb681f1dcffe6d74.slice 
       docker-fd95c597ff3171ff110b7bf440229e76c5108d5d93be75ffeab54869df734413.scope  
         21491 /pause
       docker-afa9798c9f663b21df8f38d9634469e6b4db0984124547cd472a7789c61ef752.scope  
         21680 kube-scheduler --authentication-kubeconfig=/etc/kubernetes/sche 
     kubepods-burstable-podb9af9615_8cde_4a18_8555_6da1f51b7136.slice 
       docker-48d735f7f44e3944851563f03f32c60811f81409e7378641404035dffd8c1eb4.scope  
         27424 /usr/bin/weave-npc
         27458 /usr/sbin/ulogd -v
       docker-36b418e69ae7076fe5a44d16cef223d8908016474cb65910f2fd54cca470566b.scope  
         27549 /bin/sh /home/weave/launch.sh
         27629 /home/weave/weaver --port=6783 --datapath=datapath --name=12:82 
         27825 /home/weave/kube-utils -run-reclaim-daemon -node-name=udon -pee 
       docker-7104f65b5d92a56a2df93514ed0a78cfd1090ca47b6ce4e0badc43be6c6c538e.scope  
         27011 /pause
     kubepods-burstable-pod4d7d3d81_a769_4de9_a4fb_04763b7c1605.slice 
       docker-6669168db70db4e6c741e8a047942af06dd745fae4d594291d1d6e1077b05082.scope  
         698925 /pause
       docker-d5fa78fa31f11a4c5fb9fd2e853a00f0e60e414a7bce2e0d8fcd1f6ab2b30074.scope  
          699303 /usr/bin/dumb-init -- /nginx-ingress-controller --publish-ser 
          699316 /nginx-ingress-controller --publish-service=ingress-nginx/ing 
          699405 nginx: master process /usr/local/nginx/sbin/nginx -c /etc/ngi 
         1075085 nginx: worker process
         1075086 nginx: worker process
         1075087 nginx: worker process
         1075088 nginx: worker process
         1075089 nginx: cache manager process
     kubepods-burstable-pod1976f4d6_647c_45ca_b268_95f071f064d5.slice 
       docker-4a30785f91873a7e6a191e86928a789760a054e4fa6dcd7048a059b42cf19edf.scope  
         28178 /coredns -conf /etc/coredns/Corefile
       docker-534c0a698478599277482d97a137fab8ef4d62db8a8a5cf011b4bead28246f70.scope  
         27995 /pause
     kubepods-burstable-pod1d1b9018c3c6e7aa2e803c6e9ccd2eab.slice 
       docker-589c1545d9e0cdf8ea391745c54c8f4db49f5f437b1a2e448e7744b2c12f8856.scope  
         21489 /pause
       docker-4b3708b62f4d427690f5979848c59fce522dab6c62a9c53b806ffbaef3f88e62.scope  
         21690 kube-controller-manager --authentication-kubeconfig=/etc/kubern 
   kubepods-besteffort.slice 
     kubepods-besteffort-podc7111c9e_7131_40e0_876d_be89d5ca1812.slice 
       docker-62b369de8d8cece4d33ec9fda4d23a9718379a8df8b30173d68f20bff830fed2.scope  
         514688 /pause
       docker-7cbb177bee18dbdeed21fb90e74378e2081436ad5bf116b36ad5077fe382df30.scope  
         514999 /bin/bash /usr/local/bin/run.sh
         515039 nginx: master process nginx -g daemon off;
         515040 nginx: worker process
     kubepods-besteffort-pod8bf2d7ec_4850_427f_860f_465a9ff84841.slice 
       docker-73fae81715b670255b66419a7959798b287be7bbb41e96f8b711fa529aa02f0d.scope  
         22364 /pause
       docker-26d92a720c560caaa5f8a0217bc98e486b1c032af6c7c5d75df508021d462878.scope  
         22412 /usr/local/bin/kube-proxy --config=/var/lib/kube-proxy/config.c 

Again, there s a lot going on here, but if you look for the kubepods.slice piece then you can see our pods are divided into two sets, kubepods-burstable.slice and kubepods-besteffort.slice. Under those you can see the individual pods, all of which have at least 2 separate cgroups, one of which is running /pause. Turns out this is a generic Kubernetes image which basically performs the process reaping that an init process would do on a normal system; it just sits and waits for processes to exit and cleans them up. Again, Ian Lewis has more details on the pause container. Finally let s dig into the actual containers. The pause container seems like a good place to start. We can examine the details of where the filesystem is (may differ if you re not using the overlay2 image thingy). The hex string is the container ID listed by docker ps.

# docker inspect --format=' .GraphDriver.Data.MergedDir ' 6669168db70d
/var/lib/docker/overlay2/5a2d76012476349e6b58eb6a279bac400968cefae8537082ea873b2e791ff3c6/merged
# cd /var/lib/docker/overlay2/5a2d76012476349e6b58eb6a279bac400968cefae8537082ea873b2e791ff3c6/merged
# find .   sed -e 's;^./;;'
pause
proc
.dockerenv
etc
etc/resolv.conf
etc/hostname
etc/mtab
etc/hosts
sys
dev
dev/shm
dev/pts
dev/console
# file pause
pause: ELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), statically linked, for GNU/Linux 3.2.0, BuildID[sha1]=d35dab7152881e37373d819f6864cd43c0124a65, stripped

This is a nice, minimal container. The pause binary is statically linked, so there are no extra libraries required and it s just a basic set of support devices and files. I doubt the pieces in /etc are even required. Let s try the echoserver next:

# docker inspect --format=' .GraphDriver.Data.MergedDir ' 7cbb177bee18
/var/lib/docker/overlay2/09042bc1aff16a9cba43f1a6a68f7786c4748e989a60833ec7417837c4bfaacb/merged
# cd /var/lib/docker/overlay2/09042bc1aff16a9cba43f1a6a68f7786c4748e989a60833ec7417837c4bfaacb/merged
# find .   wc -l
3358

Wow. That s a lot more stuff. Poking /etc/os-release shows why:

# grep PRETTY etc/os-release
PRETTY_NAME="Ubuntu 16.04.2 LTS"

Aha. It s an Ubuntu-based image. We can cut straight to the chase with the nginx ingress container:

# docker exec d5fa78fa31f1 grep PRETTY /etc/os-release
PRETTY_NAME="Alpine Linux v3.13"

That s a bit more reasonable an image for a container; Alpine Linux is a much smaller distro. I don t feel there s a lot more poking to do here. It s not something I d expect to do on a normal Kubernetes setup, but I wanted to dig under the hood to make sure it really was just a normal container situation. I think the next steps involve adding a bit more complexity - that means building a pod with more than a single node, and then running an application that s a bit more complicated. That should help explore two major advantages of running this sort of setup; resilency from a node dying, and the ability to scale out beyond what a single node can do.

I previously built a single node Kubernetes cluster as a test environment to learn more about it. The first thing I want to try to understand is its networking. In particular the IP addresses that are listed are all 10.* and my host s network is a 192.168/24. I understand each pod gets its own virtual ethernet interface and associated IP address, and these are generally private within the cluster (and firewalled out other than for exposed services). What does that actually look like?

$ ip route
default via 192.168.53.1 dev enx00e04c6851de
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
192.168.0.0/24 dev weave proto kernel scope link src 192.168.0.1
192.168.53.0/24 dev enx00e04c6851de proto kernel scope link src 192.168.53.147

Huh. No sign of any way to get to 10.107.66.138 (the IP my echoserver from the previous post is available on directly from the host). What about network interfaces? (under the cut because it s lengthy)

ip addr

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: enx00e04c6851de: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:e0:4c:68:51:de brd ff:ff:ff:ff:ff:ff
    inet 192.168.53.147/24 brd 192.168.53.255 scope global dynamic enx00e04c6851de
       valid_lft 41571sec preferred_lft 41571sec
3: wlp1s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 74:d8:3e:70:3b:18 brd ff:ff:ff:ff:ff:ff
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
    link/ether 02:42:18:04:9e:08 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever
5: datapath: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether d2:5a:fd:c1:56:23 brd ff:ff:ff:ff:ff:ff
7: weave: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue state UP group default qlen 1000
    link/ether 12:82:8f:ed:c7:bf brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.1/24 brd 192.168.0.255 scope global weave
       valid_lft forever preferred_lft forever
9: vethwe-datapath@vethwe-bridge: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue master datapath state UP group default
    link/ether b6:49:88:d6:6d:84 brd ff:ff:ff:ff:ff:ff
10: vethwe-bridge@vethwe-datapath: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue master weave state UP group default
    link/ether 6e:6c:03:1d:e5:0e brd ff:ff:ff:ff:ff:ff
11: vxlan-6784: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 65535 qdisc noqueue master datapath state UNKNOWN group default qlen 1000
    link/ether 9a:af:c5:0a:b3:fd brd ff:ff:ff:ff:ff:ff
13: vethwepl534c0a6@if12: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue master weave state UP group default
    link/ether 1e:ac:f1:85:61:9a brd ff:ff:ff:ff:ff:ff link-netnsid 0
15: vethwepl9ffd6b6@if14: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue master weave state UP group default
    link/ether 56:ca:71:2a:ab:39 brd ff:ff:ff:ff:ff:ff link-netnsid 1
17: vethwepl62b369d@if16: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue master weave state UP group default
    link/ether e2:a0:bb:ee:fc:73 brd ff:ff:ff:ff:ff:ff link-netnsid 2
23: vethwepl6669168@if22: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1376 qdisc noqueue master weave state UP group default
    link/ether f2:e7:e6:95:e0:61 brd ff:ff:ff:ff:ff:ff link-netnsid 3

That looks like a collection of virtual ethernet devices that are being managed by the weave networking plugin, and presumably partnered inside each pod. They re bridged to the weave interface (the master weave bit). Still no clues about the 10.* range. What about ARP?

ip neigh

168.53.1 dev enx00e04c6851de lladdr e4:8d:8c:35:98:d5 DELAY
168.0.4 dev datapath lladdr da:22:06:96:50:cb STALE
168.0.2 dev weave lladdr 66:eb:ce:16:3c:62 REACHABLE
168.53.136 dev enx00e04c6851de lladdr 00:e0:4c:39:f2:54 REACHABLE
168.0.6 dev weave lladdr 56:a9:f0:d2:9e:f3 STALE
168.0.3 dev datapath lladdr f2:42:c9:c3:08:71 STALE
168.0.3 dev weave lladdr f2:42:c9:c3:08:71 REACHABLE
168.0.2 dev datapath lladdr 66:eb:ce:16:3c:62 STALE
168.0.6 dev datapath lladdr 56:a9:f0:d2:9e:f3 STALE
168.0.4 dev weave lladdr da:22:06:96:50:cb STALE
168.0.5 dev datapath lladdr fe:6f:1b:14:56:5a STALE
168.0.5 dev weave lladdr fe:6f:1b:14:56:5a REACHABLE

Nope. That just looks like addresses on the weave managed bridge. Alright. What about firewalling?

nft list ruleset

table ip nat  
	chain DOCKER  
		iifname "docker0" counter packets 0 bytes 0 return
	 
	chain POSTROUTING  
		type nat hook postrouting priority srcnat; policy accept;
		 counter packets 531750 bytes 31913539 jump KUBE-POSTROUTING
		oifname != "docker0" ip saddr 172.17.0.0/16 counter packets 1 bytes 84 masquerade 
		counter packets 525600 bytes 31544134 jump WEAVE
	 
	chain PREROUTING  
		type nat hook prerouting priority dstnat; policy accept;
		 counter packets 180 bytes 12525 jump KUBE-SERVICES
		fib daddr type local counter packets 23 bytes 1380 jump DOCKER
	 
	chain OUTPUT  
		type nat hook output priority -100; policy accept;
		 counter packets 527005 bytes 31628455 jump KUBE-SERVICES
		ip daddr != 127.0.0.0/8 fib daddr type local counter packets 285425 bytes 17125524 jump DOCKER
	 
	chain KUBE-MARK-DROP  
		counter packets 0 bytes 0 meta mark set mark or 0x8000 
	 
	chain KUBE-MARK-MASQ  
		counter packets 0 bytes 0 meta mark set mark or 0x4000 
	 
	chain KUBE-POSTROUTING  
		mark and 0x4000 != 0x4000 counter packets 4622 bytes 277720 return
		counter packets 0 bytes 0 meta mark set mark xor 0x4000 
		 counter packets 0 bytes 0 masquerade 
	 
	chain KUBE-KUBELET-CANARY  
	 
	chain INPUT  
		type nat hook input priority 100; policy accept;
	 
	chain KUBE-PROXY-CANARY  
	 
	chain KUBE-SERVICES  
		meta l4proto tcp ip daddr 10.96.0.10  tcp dport 9153 counter packets 0 bytes 0 jump KUBE-SVC-JD5MR3NA4I4DYORP
		meta l4proto tcp ip daddr 10.107.66.138  tcp dport 8080 counter packets 1 bytes 60 jump KUBE-SVC-666FUMINWJLRRQPD
		meta l4proto tcp ip daddr 10.111.16.129  tcp dport 443 counter packets 0 bytes 0 jump KUBE-SVC-EZYNCFY2F7N6OQA2
		meta l4proto tcp ip daddr 10.96.9.41  tcp dport 443 counter packets 0 bytes 0 jump KUBE-SVC-EDNDUDH2C75GIR6O
		meta l4proto tcp ip daddr 192.168.53.147  tcp dport 443 counter packets 0 bytes 0 jump KUBE-XLB-EDNDUDH2C75GIR6O
		meta l4proto tcp ip daddr 10.96.9.41  tcp dport 80 counter packets 0 bytes 0 jump KUBE-SVC-CG5I4G2RS3ZVWGLK
		meta l4proto tcp ip daddr 192.168.53.147  tcp dport 80 counter packets 0 bytes 0 jump KUBE-XLB-CG5I4G2RS3ZVWGLK
		meta l4proto tcp ip daddr 10.96.0.1  tcp dport 443 counter packets 0 bytes 0 jump KUBE-SVC-NPX46M4PTMTKRN6Y
		meta l4proto udp ip daddr 10.96.0.10  udp dport 53 counter packets 0 bytes 0 jump KUBE-SVC-TCOU7JCQXEZGVUNU
		meta l4proto tcp ip daddr 10.96.0.10  tcp dport 53 counter packets 0 bytes 0 jump KUBE-SVC-ERIFXISQEP7F7OF4
		 fib daddr type local counter packets 3312 bytes 198720 jump KUBE-NODEPORTS
	 
	chain KUBE-NODEPORTS  
		meta l4proto tcp  tcp dport 31529 counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp  tcp dport 31529 counter packets 0 bytes 0 jump KUBE-SVC-666FUMINWJLRRQPD
		meta l4proto tcp ip saddr 127.0.0.0/8  tcp dport 30894 counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp  tcp dport 30894 counter packets 0 bytes 0 jump KUBE-XLB-EDNDUDH2C75GIR6O
		meta l4proto tcp ip saddr 127.0.0.0/8  tcp dport 32740 counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp  tcp dport 32740 counter packets 0 bytes 0 jump KUBE-XLB-CG5I4G2RS3ZVWGLK
	 
	chain KUBE-SVC-NPX46M4PTMTKRN6Y  
		 counter packets 0 bytes 0 jump KUBE-SEP-Y6PHKONXBG3JINP2
	 
	chain KUBE-SEP-Y6PHKONXBG3JINP2  
		ip saddr 192.168.53.147  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.53.147:6443
	 
	chain WEAVE  
		# match-set weaver-no-masq-local dst  counter packets 135966 bytes 8160820 return
		ip saddr 192.168.0.0/24 ip daddr 224.0.0.0/4 counter packets 0 bytes 0 return
		ip saddr != 192.168.0.0/24 ip daddr 192.168.0.0/24 counter packets 0 bytes 0 masquerade 
		ip saddr 192.168.0.0/24 ip daddr != 192.168.0.0/24 counter packets 33 bytes 2941 masquerade 
	 
	chain WEAVE-CANARY  
	 
	chain KUBE-SVC-JD5MR3NA4I4DYORP  
		  counter packets 0 bytes 0 jump KUBE-SEP-6JI23ZDEH4VLR5EN
		 counter packets 0 bytes 0 jump KUBE-SEP-FATPLMAF37ZNQP5P
	 
	chain KUBE-SEP-6JI23ZDEH4VLR5EN  
		ip saddr 192.168.0.2  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.2:9153
	 
	chain KUBE-SVC-TCOU7JCQXEZGVUNU  
		  counter packets 0 bytes 0 jump KUBE-SEP-JTN4UBVS7OG5RONX
		 counter packets 0 bytes 0 jump KUBE-SEP-4TCKAEJ6POVEFPVW
	 
	chain KUBE-SEP-JTN4UBVS7OG5RONX  
		ip saddr 192.168.0.2  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto udp   counter packets 0 bytes 0 dnat to 192.168.0.2:53
	 
	chain KUBE-SVC-ERIFXISQEP7F7OF4  
		  counter packets 0 bytes 0 jump KUBE-SEP-UPZX2EM3TRFH2ASL
		 counter packets 0 bytes 0 jump KUBE-SEP-KPHYKKPVMB473Z76
	 
	chain KUBE-SEP-UPZX2EM3TRFH2ASL  
		ip saddr 192.168.0.2  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.2:53
	 
	chain KUBE-SEP-4TCKAEJ6POVEFPVW  
		ip saddr 192.168.0.3  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto udp   counter packets 0 bytes 0 dnat to 192.168.0.3:53
	 
	chain KUBE-SEP-KPHYKKPVMB473Z76  
		ip saddr 192.168.0.3  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.3:53
	 
	chain KUBE-SEP-FATPLMAF37ZNQP5P  
		ip saddr 192.168.0.3  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.3:9153
	 
	chain KUBE-SVC-666FUMINWJLRRQPD  
		 counter packets 1 bytes 60 jump KUBE-SEP-LYLDBZYLHY4MT3AQ
	 
	chain KUBE-SEP-LYLDBZYLHY4MT3AQ  
		ip saddr 192.168.0.4  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 1 bytes 60 dnat to 192.168.0.4:8080
	 
	chain KUBE-XLB-EDNDUDH2C75GIR6O  
		 fib saddr type local counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		 fib saddr type local counter packets 0 bytes 0 jump KUBE-SVC-EDNDUDH2C75GIR6O
		 counter packets 0 bytes 0 jump KUBE-SEP-BLQHCYCSXY3NRKLC
	 
	chain KUBE-XLB-CG5I4G2RS3ZVWGLK  
		 fib saddr type local counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		 fib saddr type local counter packets 0 bytes 0 jump KUBE-SVC-CG5I4G2RS3ZVWGLK
		 counter packets 0 bytes 0 jump KUBE-SEP-5XVRKWM672JGTWXH
	 
	chain KUBE-SVC-EDNDUDH2C75GIR6O  
		 counter packets 0 bytes 0 jump KUBE-SEP-BLQHCYCSXY3NRKLC
	 
	chain KUBE-SEP-BLQHCYCSXY3NRKLC  
		ip saddr 192.168.0.5  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.5:443
	 
	chain KUBE-SVC-CG5I4G2RS3ZVWGLK  
		 counter packets 0 bytes 0 jump KUBE-SEP-5XVRKWM672JGTWXH
	 
	chain KUBE-SEP-5XVRKWM672JGTWXH  
		ip saddr 192.168.0.5  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.5:80
	 
	chain KUBE-SVC-EZYNCFY2F7N6OQA2  
		 counter packets 0 bytes 0 jump KUBE-SEP-JYW326XAJ4KK7QPG
	 
	chain KUBE-SEP-JYW326XAJ4KK7QPG  
		ip saddr 192.168.0.5  counter packets 0 bytes 0 jump KUBE-MARK-MASQ
		meta l4proto tcp   counter packets 0 bytes 0 dnat to 192.168.0.5:8443
	 
 
table ip filter  
	chain DOCKER  
	 
	chain DOCKER-ISOLATION-STAGE-1  
		iifname "docker0" oifname != "docker0" counter packets 0 bytes 0 jump DOCKER-ISOLATION-STAGE-2
		counter packets 0 bytes 0 return
	 
	chain DOCKER-ISOLATION-STAGE-2  
		oifname "docker0" counter packets 0 bytes 0 drop
		counter packets 0 bytes 0 return
	 
	chain FORWARD  
		type filter hook forward priority filter; policy drop;
		iifname "weave"  counter packets 213 bytes 54014 jump WEAVE-NPC-EGRESS
		oifname "weave"  counter packets 150 bytes 30038 jump WEAVE-NPC
		oifname "weave" ct state new counter packets 0 bytes 0 log group 86 
		oifname "weave" counter packets 0 bytes 0 drop
		iifname "weave" oifname != "weave" counter packets 33 bytes 2941 accept
		oifname "weave" ct state related,established counter packets 0 bytes 0 accept
		 counter packets 0 bytes 0 jump KUBE-FORWARD
		ct state new  counter packets 0 bytes 0 jump KUBE-SERVICES
		ct state new  counter packets 0 bytes 0 jump KUBE-EXTERNAL-SERVICES
		counter packets 0 bytes 0 jump DOCKER-USER
		counter packets 0 bytes 0 jump DOCKER-ISOLATION-STAGE-1
		oifname "docker0" ct state related,established counter packets 0 bytes 0 accept
		oifname "docker0" counter packets 0 bytes 0 jump DOCKER
		iifname "docker0" oifname != "docker0" counter packets 0 bytes 0 accept
		iifname "docker0" oifname "docker0" counter packets 0 bytes 0 accept
	 
	chain DOCKER-USER  
		counter packets 0 bytes 0 return
	 
	chain KUBE-FIREWALL  
		 mark and 0x8000 == 0x8000 counter packets 0 bytes 0 drop
		ip saddr != 127.0.0.0/8 ip daddr 127.0.0.0/8  ct status dnat counter packets 0 bytes 0 drop
	 
	chain OUTPUT  
		type filter hook output priority filter; policy accept;
		ct state new  counter packets 527014 bytes 31628984 jump KUBE-SERVICES
		counter packets 36324809 bytes 6021214027 jump KUBE-FIREWALL
		meta l4proto != esp  mark and 0x20000 == 0x20000 counter packets 0 bytes 0 drop
	 
	chain INPUT  
		type filter hook input priority filter; policy accept;
		 counter packets 35869492 bytes 5971008896 jump KUBE-NODEPORTS
		ct state new  counter packets 390938 bytes 23457377 jump KUBE-EXTERNAL-SERVICES
		counter packets 36249774 bytes 6030068622 jump KUBE-FIREWALL
		meta l4proto tcp ip daddr 127.0.0.1 tcp dport 6784 fib saddr type != local ct state != related,established  counter packets 0 bytes 0 drop
		iifname "weave" counter packets 907273 bytes 88697229 jump WEAVE-NPC-EGRESS
		counter packets 34809601 bytes 5818213726 jump WEAVE-IPSEC-IN
	 
	chain KUBE-KUBELET-CANARY  
	 
	chain KUBE-PROXY-CANARY  
	 
	chain KUBE-EXTERNAL-SERVICES  
	 
	chain KUBE-NODEPORTS  
		meta l4proto tcp  tcp dport 32196 counter packets 0 bytes 0 accept
		meta l4proto tcp  tcp dport 32196 counter packets 0 bytes 0 accept
	 
	chain KUBE-SERVICES  
	 
	chain KUBE-FORWARD  
		ct state invalid counter packets 0 bytes 0 drop
		 mark and 0x4000 == 0x4000 counter packets 0 bytes 0 accept
		 ct state related,established counter packets 0 bytes 0 accept
		 ct state related,established counter packets 0 bytes 0 accept
	 
	chain WEAVE-NPC-INGRESS  
	 
	chain WEAVE-NPC-DEFAULT  
		# match-set weave-;rGqyMIl1HN^cfDki~Z$3]6!N dst  counter packets 14 bytes 840 accept
		# match-set weave-P.B !ZhkAr5q=XZ?3 tMBA+0 dst  counter packets 0 bytes 0 accept
		# match-set weave-Rzff h:=]JaaJl/G;(XJpGjZ[ dst  counter packets 0 bytes 0 accept
		# match-set weave-]B*(W?)t*z5O17G044[gUo#$l dst  counter packets 0 bytes 0 accept
		# match-set weave-iLgO^ o=U/*%KE[@=W:l~ 9T dst  counter packets 9 bytes 540 accept
	 
	chain WEAVE-NPC  
		ct state related,established counter packets 124 bytes 28478 accept
		ip daddr 224.0.0.0/4 counter packets 0 bytes 0 accept
		# PHYSDEV match --physdev-out vethwe-bridge --physdev-is-bridged counter packets 3 bytes 180 accept
		ct state new counter packets 23 bytes 1380 jump WEAVE-NPC-DEFAULT
		ct state new counter packets 0 bytes 0 jump WEAVE-NPC-INGRESS
	 
	chain WEAVE-NPC-EGRESS-ACCEPT  
		counter packets 48 bytes 3769 meta mark set mark or 0x40000 
	 
	chain WEAVE-NPC-EGRESS-CUSTOM  
	 
	chain WEAVE-NPC-EGRESS-DEFAULT  
		# match-set weave-s_+ChJId4Uy_$ G;WdH ~TK)I src  counter packets 0 bytes 0 jump WEAVE-NPC-EGRESS-ACCEPT
		# match-set weave-s_+ChJId4Uy_$ G;WdH ~TK)I src  counter packets 0 bytes 0 return
		# match-set weave-E1ney4o[ojNrLk.6rOHi;7MPE src  counter packets 31 bytes 2749 jump WEAVE-NPC-EGRESS-ACCEPT
		# match-set weave-E1ney4o[ojNrLk.6rOHi;7MPE src  counter packets 31 bytes 2749 return
		# match-set weave-41s)5vQ^o/xWGz6a20N:~?# E src  counter packets 0 bytes 0 jump WEAVE-NPC-EGRESS-ACCEPT
		# match-set weave-41s)5vQ^o/xWGz6a20N:~?# E src  counter packets 0 bytes 0 return
		# match-set weave-sui%__gZ kX~oZgI_Ttqp=Dp src  counter packets 0 bytes 0 jump WEAVE-NPC-EGRESS-ACCEPT
		# match-set weave-sui%__gZ kX~oZgI_Ttqp=Dp src  counter packets 0 bytes 0 return
		# match-set weave-nmMUaDKV*YkQcP5s?Q[R54Ep3 src  counter packets 17 bytes 1020 jump WEAVE-NPC-EGRESS-ACCEPT
		# match-set weave-nmMUaDKV*YkQcP5s?Q[R54Ep3 src  counter packets 17 bytes 1020 return
	 
	chain WEAVE-NPC-EGRESS  
		ct state related,established counter packets 907425 bytes 88746642 accept
		# PHYSDEV match --physdev-in vethwe-bridge --physdev-is-bridged counter packets 0 bytes 0 return
		fib daddr type local counter packets 11 bytes 640 return
		ip daddr 224.0.0.0/4 counter packets 0 bytes 0 return
		ct state new counter packets 50 bytes 3961 jump WEAVE-NPC-EGRESS-DEFAULT
		ct state new mark and 0x40000 != 0x40000 counter packets 2 bytes 192 jump WEAVE-NPC-EGRESS-CUSTOM
	 
	chain WEAVE-IPSEC-IN  
	 
	chain WEAVE-CANARY  
	 
 
table ip mangle  
	chain KUBE-KUBELET-CANARY  
	 
	chain PREROUTING  
		type filter hook prerouting priority mangle; policy accept;
	 
	chain INPUT  
		type filter hook input priority mangle; policy accept;
		counter packets 35716863 bytes 5906910315 jump WEAVE-IPSEC-IN
	 
	chain FORWARD  
		type filter hook forward priority mangle; policy accept;
	 
	chain OUTPUT  
		type route hook output priority mangle; policy accept;
		counter packets 35804064 bytes 5938944956 jump WEAVE-IPSEC-OUT
	 
	chain POSTROUTING  
		type filter hook postrouting priority mangle; policy accept;
	 
	chain KUBE-PROXY-CANARY  
	 
	chain WEAVE-IPSEC-IN  
	 
	chain WEAVE-IPSEC-IN-MARK  
		counter packets 0 bytes 0 meta mark set mark or 0x20000
	 
	chain WEAVE-IPSEC-OUT  
	 
	chain WEAVE-IPSEC-OUT-MARK  
		counter packets 0 bytes 0 meta mark set mark or 0x20000
	 
	chain WEAVE-CANARY  
	 
 

Wow. That s a lot of nftables entries, but it explains what s going on. We have a nat entry for:

meta l4proto tcp ip daddr 10.107.66.138 tcp dport 8080 counter packets 1 bytes 60 jump KUBE-SVC-666FUMINWJLRRQPD

which ends up going to KUBE-SEP-LYLDBZYLHY4MT3AQ and:

meta l4proto tcp counter packets 1 bytes 60 dnat to 192.168.0.4:8080

So packets headed for our echoserver are eventually ending up in a container that has a local IP address of 192.168.0.4. Which we can see in our routing table via the weave interface. Mystery explained. We can see the ingress for the externally visible HTTP service as well:

meta l4proto tcp ip daddr 192.168.33.147 tcp dport 80 counter packets 0 bytes 0 jump KUBE-XLB-CG5I4G2RS3ZVWGLK

which ends up redirected to:

meta l4proto tcp counter packets 0 bytes 0 dnat to 192.168.0.5:80

So from that we d expect the IP inside the echoserver pod to be 192.168.0.4 and the IP address instead our nginx ingress pod to be 192.168.0.5. Let s look:

root@udon:/# docker ps   grep echoserver
7cbb177bee18   k8s.gcr.io/echoserver                 "/usr/local/bin/run. "   3 days ago   Up 3 days             k8s_echoserver_hello-node-59bffcc9fd-8hkgb_default_c7111c9e-7131-40e0-876d-be89d5ca1812_0
root@udon:/# docker exec -it 7cbb177bee18 /bin/bash
root@hello-node-59bffcc9fd-8hkgb:/# awk '/32 host/   print f    f=$2 ' <<< "$(</proc/net/fib_trie)"   sort -u
127.0.0.1
192.168.0.4

It s a slightly awkward method of determining the local IPs addresses due to the stripped down nature of the container, but it clearly shows the expected 192.168.0.4 address. I ve touched here upon the ability to actually enter a container and have a poke around its running environment by using docker directly. Next step is to use that to investigate what containers have actually been spun up and what they re doing. I ll also revisit networking when I get to the point of building a multi-node cluster, to examine how the bridging between different hosts is done.

Kubernetes is about giving up control. As someone who likes to understand what s going on that s made it hard for me to embrace it. I ve also mostly been able to ignore it, which has helped. However I m aware it s incredibly popular, and there s some infrastructure at work that uses it. While it s not my responsibility I always find having an actual implementation of something is useful in understanding it generally, so I decided it was time to dig in and learn something new. First up, I should say I understand the trade-off here about handing a bunch of decisions off to Kubernetes about the underlying platform allowing development/deployment to concentrate on a nice consistent environment. I get the analogy with the shipping container model where you can abstract out both sides knowing all you have to do is conform to the TEU API. In terms of the underlying concepts I ve got some virtualisation and container experience, so I m not coming at this as a complete newcomer. And I understand multi-site dynamically routed networks. That said, let s start with a basic goal. I d like to understand k8s (see, I can be cool and use the short name) enough to be comfortable with what s going on under the hood and be able to examine a running instance safely (i.e. enough confidence about pulling logs, probing state etc without fearing I might modify state). That ll mean when I come across such infrastructure I have enough tools to be able to hopefully learn from it. To do this I figure I ll need to build myself a cluster and deploy some things on it, then poke it. I ll start by doing so on bare metal; that removes variables around cloud providers and virtualisation and gives me an environment I know is isolated from everything else. I happen to have a GMK NucBox available, so I ll use that. As a first step I m aiming to get a single node cluster deployed running some sort of web accessible service that is visible from the rest of my network. That should mean I ve covered the basics of a Kubernetes install, a running service and actually making it accessible. Of course I m running Debian. I ve got a Bullseye (Debian 11) install - not yet released as stable, but in freeze and therefore not a moving target. I wanted to use packages from Debian as much as possible but it seems that the bits of Kubernetes available in main are mostly just building blocks and not a great starting point for someone new to Kubernetes. So to do the initial install I did the following:

# Install docker + nftables from Debian
apt install docker.io nftables
# Add the Kubernetes repo and signing key
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg > /etc/apt/k8s.gpg
cat > /etc/apt/sources.list.d/kubernetes.list <<EOF
deb [signed-by=/etc/apt/k8s.gpg] https://apt.kubernetes.io/ kubernetes-xenial main
EOF
apt update
apt install kubelet kubeadm kubectl

That resulted in a 1.21.1-00 install, which is current at the time of writing. I then used kubeadm to create the cluster:

kubeadm init --apiserver-advertise-address 192.168.53.147 --apiserver-cert-extra-sans udon.mynetwork

The extra parameters were to make the API server externally accessible from the host. I don t know if that was a good idea or not at this stage kubeadm spat out a bunch of instructions but the key piece was about copying the credentials to my user account. So I did:

mkdir ~noodles/.kube
cp -i /etc/kubernetes/admin.conf ~noodles/.kube/config
chown -R noodles ~noodles/.kube/

I then was able to see my pod:

noodles@udon:~$ kubectl get nodes
NAME   STATUS     ROLES                  AGE     VERSION
udon   NotReady   control-plane,master   4m31s   v1.21.1

Ooooh. But why s it NotReady? Seems like it s a networking issue and I need to install a networking provider. The documentation on this is appalling. Flannel gets recommended as a simple option but then turns out to need a --pod-network-cidr option passed to kubeadm and I didn t feel like cleaning up and running again (I ve omitted all the false starts it took me to get to this point). Another pointer was to Weave so I decided to try that with the following magic runes:

mkdir -p /var/lib/weave
head -c 16 /dev/urandom   shasum -a 256   cut -d " " -f1 > /var/lib/weave/weave-passwd
kubectl create secret -n kube-system generic weave-passwd --from-file=/var/lib/weave/weave-passwd
kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version   base64   tr -d '\n')&password-secret=weave-passwd&env.IPALLOC_RANGE=192.168.0.0/24"

(I believe what that s doing is the first 3 lines create a password and store it into the internal Kubernetes config so the weave pod can retrieve it. The final line then grabs a YAML config from Weaveworks to configure up weave. My intention is to delve deeper into what s going on here later; for now the primary purpose is to get up and running.) As I m running a single node cluster I then had to untaint my control node so I could use it as a worker node too:

kubectl taint nodes --all node-role.kubernetes.io/master-

And then:

noodles@udon:~$ kubectl get nodes
NAME   STATUS   ROLES                  AGE   VERSION
udon   Ready    control-plane,master   15m   v1.21.1

Result. What s actually running? Nothing except the actual system stuff, so we need to ask for all namespaces:

noodles@udon:~$ kubectl get pods --all-namespaces
NAMESPACE     NAME                           READY   STATUS    RESTARTS   AGE
kube-system   coredns-558bd4d5db-4nvrg       1/1     Running   0          18m
kube-system   coredns-558bd4d5db-flrfq       1/1     Running   0          18m
kube-system   etcd-udon                      1/1     Running   0          18m
kube-system   kube-apiserver-udon            1/1     Running   0          18m
kube-system   kube-controller-manager-udon   1/1     Running   0          18m
kube-system   kube-proxy-6d8kg               1/1     Running   0          18m
kube-system   kube-scheduler-udon            1/1     Running   0          18m
kube-system   weave-net-mchmg                2/2     Running   1          3m26s

These are all things I m going to have to learn about, but for now I ll nod and smile and pretend I understand. Now I want to actually deploy something to the cluster. I ended up with a simple HTTP echoserver (though it s not entirely clear that s actually the source for what I ended up pulling):

$ kubectl create deployment hello-node --image=k8s.gcr.io/echoserver:1.10
deployment.apps/hello-node created
$ kubectl get pod
NAME                          READY   STATUS    RESTARTS   AGE
hello-node-59bffcc9fd-8hkgb   1/1     Running   0          36s
$ kubectl expose deployment hello-node --type=NodePort --port=8080
$ kubectl get services
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
hello-node   NodePort    10.107.66.138   <none>        8080:31529/TCP   1m

Looks good. And to test locally:

curl http://10.107.66.138:8080/

Hostname: hello-node-59bffcc9fd-8hkgb
Pod Information:
	-no pod information available-
Server values:
	server_version=nginx: 1.13.3 - lua: 10008
Request Information:
	client_address=192.168.53.147
	method=GET
	real path=/
	query=
	request_version=1.1
	request_scheme=http
	request_uri=http://10.107.66.138:8080/
Request Headers:
	accept=*/*
	host=10.107.66.138:8080
	user-agent=curl/7.74.0
Request Body:
	-no body in request-

Neat. But my external network is 192.168.53.0/24 and that s a 10.* address so how do I actually make it visible to other hosts? What I seem to need is an Ingress Controller which provide some sort of proxy between the outside world and pods within the cluster. Let s pick nginx because at least I have some vague familiarity with that and it seems like it should be able to do a bunch of HTTP redirection to different pods depending on the incoming request.

kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v0.46.0/deploy/static/provider/cloud/deploy.yaml

I then want to expose the hello-node to the outside world and I finally had to write some YAML:

cat > hello-ingress.yaml <<EOF
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /$1
spec:
  rules:
    - host: udon.mynetwork
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: hello-node
                port:
                  number: 8080
EOF

i.e. incoming requests to http://udon.mynetwork/ should go to the hello-node on port 8080. I applied this:

$ kubectl apply -f hello-ingress.yaml
ingress.networking.k8s.io/example-ingress created
$ kubectl get ingress
NAME              CLASS    HOSTS            ADDRESS   PORTS   AGE
example-ingress   <none>   udon.mynetwork             80      3m8s

No address? What have I missed? Let s check the nginx service, which apparently lives in the ingress-nginx namespace:

noodles@udon:~$ kubectl get services -n ingress-nginx
NAME                                 TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)                    AGE
ingress-nginx-controller             LoadBalancer   10.96.9.41      <pending>     80:32740/TCP,443:30894/TCP 13h
ingress-nginx-controller-admission   ClusterIP      10.111.16.129   <none>        443/TCP                    13h

<pending> does not seem like something I want. Digging around it seems I need to configure the external IP. So I do:

kubectl patch svc ingress-nginx-controller -n ingress-nginx -p \
	' "spec":  "type": "LoadBalancer", "externalIPs":["192.168.53.147"] '

and things look happier:

noodles@udon:~$ kubectl get services -n ingress-nginx
NAME                                 TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)                 AGE
ingress-nginx-controller             LoadBalancer   10.96.9.41      192.168.53.147   80:32740/TCP,443:30894/TCP   14h
ingress-nginx-controller-admission   ClusterIP      10.111.16.129   <none>           443/TCP                 14h
noodles@udon:~$ kubectl get ingress
NAME              CLASS    HOSTS           ADDRESS          PORTS   AGE
example-ingress   <none>   udon.mynetwork  192.168.53.147   80      14h

Let s try a curl from a remote host:

curl http://udon.mynetwork/

Hostname: hello-node-59bffcc9fd-8hkgb
Pod Information:
	-no pod information available-
Server values:
	server_version=nginx: 1.13.3 - lua: 10008
Request Information:
	client_address=192.168.0.5
	method=GET
	real path=/
	query=
	request_version=1.1
	request_scheme=http
	request_uri=http://udon.mynetwork:8080/
Request Headers:
	accept=*/*
	host=udon.mynetwork
	user-agent=curl/7.64.0
	x-forwarded-for=192.168.53.136
	x-forwarded-host=udon.mynetwork
	x-forwarded-port=80
	x-forwarded-proto=http
	x-real-ip=192.168.53.136
	x-request-id=6aaef8feaaa4c7d07c60b2d05c45f75c
	x-scheme=http
Request Body:
	-no body in request-

Ok, so that seems like success. I ve got a single node cluster running a single actual application pod (the echoserver) and exporting it to the outside world. That s enough to start poking under the hood. Which is for another post, as this one is already getting longer than I d like. I ll just leave some final thoughts of things I need to work out:

What s going on with the networking?
Where s the IPv6 (the host in question has native IPv6 routing)?
How do I deploy my own application pod?
I should look at a multiple host setup (i.e. a real cluster).
How much of this goes away if I use a cloud provider like AWS to run the cluster?
Can I do this with the Debian Kubernetes packages?

I wrote previously about my DeskPi Pro + 8GB Pi 4 setup. My main complaint at the time was the fact one of the forward facing USB ports broke off early on in my testing. For day to day use that hasn t been a problem, but it did mar the whole experience. Last week I received an unexpected email telling me The new updated PCB Board for your DeskPi order was shipped. . Apparently this was due to problems with identifying SSDs and WiFi/HDMI issues. I wasn t quite sure how much of the internals they d be replacing, so I was pleasantly surprised when it turned out to be most of them; including the PCB with the broken USB port on my device. DeskPi Pro replacement PCB

They also provided a set of feet allowing for vertical mounting of the device, which was a nice touch. The USB/SATA bridge chip in use has changed; the original was:

usb 2-1: New USB device found, idVendor=152d, idProduct=0562, bcdDevice= 1.09
usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 2-1: Product: RPi_SSD
usb 2-1: Manufacturer: 52Pi
usb 2-1: SerialNumber: DD5641988389F

and the new one is:

usb 2-1: New USB device found, idVendor=174c, idProduct=1153, bcdDevice= 0.01
usb 2-1: New USB device strings: Mfr=2, Product=3, SerialNumber=1
usb 2-1: Product: AS2115
usb 2-1: Manufacturer: ASMedia
usb 2-1: SerialNumber: 00000000000000000000

That s a move from a JMicron 6Gb/s bridge to an ASMedia 3Gb/s bridge. It seems there are compatibility issues with the JMicron that mean the downgrade is the preferred choice. I haven t retried the original SSD I wanted to use (that wasn t detected), but I did wonder if this might have resolved that issue too. Replacing the PCB was easier than the original install; everything was provided pre-assembled and I just had to unscrew the Pi4 and slot it out, then screw it into the new PCB assembly. Everything booted fine without the need for any configuration tweaks. Nice and dull. I ve tried plugging things into the new USB ports and they seem ok so far as well. However I also then ended up pulling in a new backports kernel from Debian (upgrading from 5.9 to 5.10) which resulted in a failure to boot. The kernel and initramfs were loaded fine, but no login prompt ever appeared. Some digging led to the discovery that a change in boot ordering meant USB was not being enabled. The solution is to add reset_raspberrypi to the /etc/initramfs-tools/modules file - that way this module is available in the initramfs, the appropriate pre-USB reset can happen and everything works just fine again. The other niggle with the new kernel was a regular set of errors in the kernel log:

mmc1: Timeout waiting for hardware cmd interrupt.
mmc1: sdhci: ============ SDHCI REGISTER DUMP ===========

and a set of registers afterwards, roughly every 10s or so. This seems to be fallout from an increase in the core clock due to the VC4 driver now being enabled, the fact I have no SD card in the device and a lack of working card-detect line for the MicroSD slot. There s a GitHub issue but I solved it by removing the sdhci_iproc for now - I m not using the wifi so loss of MMC isn t a problem. Credit to DeskPi for how they handled this. I didn t have to do anything and didn t even realise anything was happening until I got the email with my tracking number and a description of what they were sending out in it. Delivery took less than a week. This is a great example of how to handle a product issue - no effort required on the part of the customer.

I ve mentioned in the past my twisted EE network setup from when I moved in to my current house. The 4GEE WiFi Mini (also known as the EE Osprey 2 Mini or the EE40VB, and actually a rebadged Alcatel Y853VB) has been sitting unused since then, so I figured I d see about trying to get a shell on it. TL;DR: Of course it s running Linux, there s a couple of test points internally which bring out the serial console, but after finding those and logging in I discovered it s running ADB on port 5555 quite happily available without authentication both via wifi and the USB port. So if you have physical or local network access, instant root shell. Well done, folks. And then I bricked it before I could do anything more interesting. There s a lack of information about this device out there - most of the links I can find are around removing the SIM lock - so I thought I d document the pieces I found just in case anyone else is trying to figure it out. It s based around a Qualcomm MDM9607 SoC, paired with 64M RAM and 256M NAND flash. Wifi is via an RTL8192ES. Kernel is 3.18.20. Busybox is v1.23.1. It s running dnsmasq but I didn t grab the version. Of course there s no source or offer of source provided. Taking it apart is fairly easy. There s a single screw to remove, just beside the SIM slot. The coloured rim can then be carefully pried away from the back, revealing the battery. There are then 4 screws in the corners which need removed in order to be able to lift out the actual PCB and gain access to the serial console test points. EE40VB PCB serial console test points

My mistake was going poking around trying to figure out where the updates are downloaded from - I know I m running a slightly older release than what s current, and the device can do an automatic download + update. Top tip; don t run Jrdrecovery. It ll error on finding /cache/update.zip and wipe the main partition anyway. That ll leave you in a boot loop where the device boots the recovery partition which tries to install /cache/update.zip which of course still doesn t exist. So. Where next? First, I need to get the device into a state where I can actually do something other than watch it boot into recovery, fail to flash and reboot. Best guess at present is to try and get it to enter the Qualcomm EDL (Emergency Download) mode. That might be possible with a custom USB cable that grounds D+ on boot. Alternatively I need to probe some of the other test points on the PCB and see if grounding any of those helps enter EDL mode. I then need a suitable firehose OEM-signed programmer image. And then I need to actually get hold of a proper EE40VB firmware image, either via one of the OTA update files or possibly via an Alcatel ADSU image (though no idea how to get hold of one, other than by posting to a random GSM device forum and hoping for the kindness of strangers). More updates if/when I make progress

Qualcomm bootloader log

Format: Log Type - Time(microsec) - Message - Optional Info
Log Type: B - Since Boot(Power On Reset),  D - Delta,  S - Statistic
S - QC_IMAGE_VERSION_STRING=BOOT.BF.3.1.2-00053
S - IMAGE_VARIANT_STRING=LAATANAZA
S - OEM_IMAGE_VERSION_STRING=linux3
S - Boot Config, 0x000002e1
B -    105194 - SBL1, Start
D -     61885 - QSEE Image Loaded, Delta - (451964 Bytes)
D -     30286 - RPM Image Loaded, Delta - (151152 Bytes)
B -    459330 - Roger:boot_jrd_oem_main
B -    461526 - Welcome to key_check_poweron!!!
B -    466436 - REG0x00, rc=47
B -    469120 - REG0x01, rc=1f
B -    472018 - REG0x02, rc=1c
B -    474885 - REG0x03, rc=47
B -    477782 - REG0x04, rc=b2
B -    480558 - REG0x05, rc=
B -    483272 - REG0x06, rc=9e
B -    486139 - REG0x07, rc=
B -    488854 - REG0x08, rc=a4
B -    491721 - REG0x09, rc=80
B -    494130 - bq24295_probe: vflt/vsys/vprechg=0mV/0mV/0mV, tprechg/tfastchg=0Min/0Min, [0C, 0C]
B -    511546 - come to calculate vol and temperature!!
B -    511637 - ##############battery_core_convert_vntc: NTC_voltage=1785690
B -    517280 - battery_core_convert_vntc: <-44C, 1785690uV>, present=0
B -    529358 - bq24295_set_current_limit: setting=0mA, mode=-1, input/fastchg/prechg/termchg=-1mA/0mA/0mA/0mA
B -    534360 - bq24295_set_charge_current, rc=0,reg_val=0,i=0
B -    539636 - bq24295_enable_charge: setting=0, chg_enable=-1, otg_enable=0
B -    546072 - bq24295_enable_charging: enable_charging=0
B -    552172 - bq24295_set_current_limit: setting=0mA, mode=-1, input/fastchg/prechg/termchg=-1mA/0mA/0mA/0mA
B -    561566 - bq24295_set_charge_current, rc=0,reg_val=0,i=0
B -    567056 - bq24295_enable_charge: setting=0, chg_enable=0, otg_enable=0
B -    579286 - come to calculate vol and temperature!!
B -    579378 - ##############battery_core_convert_vntc: NTC_voltage=1785777
B -    585539 - battery_core_convert_vntc: <-44C, 1785777uV>, present=0
B -    597617 - charge_main: battery is plugout!!
B -    597678 - Welcome to pca955x_probe!!!
B -    601063 - pca955x_probe: PCA955X probed successfully!
D -     27511 - APPSBL Image Loaded, Delta - (179348 Bytes)
B -    633271 - QSEE Execution, Start
D -       213 - QSEE Execution, Delta
B -    638944 - >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>Start writting JRD RECOVERY BOOT
B -    650107 - >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>Start writting  RECOVERY BOOT
B -    653218 - >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>read_buf[0] == 0
B -    659044 - SBL1, End
D -    556137 - SBL1, Delta
S - Throughput, 2000 KB/s  (782884 Bytes,  278155 us)
S - DDR Frequency, 240 MHz

littlekernel aboot log

Android Bootloader - UART_DM Initialized!!!
[0] welcome to lk
[0] SCM call: 0x2000601 failed with :fffffffc
[0] Failed to initialize SCM
[10] platform_init()
[10] target_init()
[10] smem ptable found: ver: 4 len: 17
[10] ERROR: No devinfo partition found
[10] Neither 'config' nor 'frp' partition found
[30] voltage of NTC  is 1789872!
[30] voltage of BAT  is 3179553!
[30] usb present is 1!
[30] Loading (boot) image (4171776): start
[530] Loading (boot) image (4171776): done
[540] DTB Total entry: 25, DTB version: 3
[540] Using DTB entry 0x00000129/00010000/0x00000008/0 for device 0x00000129/00010000/0x00010008/0
[560] JRD_CHG_OFF_FEATURE!
[560] come to jrd_target_pause_for_battery_charge!
[570] power_on_status.hard_reset = 0x0
[570] power_on_status.smpl = 0x0
[570] power_on_status.rtc = 0x0
[580] power_on_status.dc_chg = 0x0
[580] power_on_status.usb_chg = 0x0
[580] power_on_status.pon1 = 0x1
[590] power_on_status.cblpwr = 0x0
[590] power_on_status.kpdpwr = 0x0
[590] power_on_status.bugflag = 0x0
[590] cmdline: noinitrd  rw console=ttyHSL0,115200,n8 androidboot.hardware=qcom ehci-hcd.park=3 msm_rtb.filter=0x37 lpm_levels.sleep_disabled=1  earlycon=msm_hsl_uart,0x78b3000  androidboot.serialno=7e6ba58c androidboot.baseband=msm rootfstype=ubifs rootflags=b
[620] Updating device tree: start
[720] Updating device tree: done
[720] booting linux @ 0x80008000, ramdisk @ 0x80008000 (0), tags/device tree @ 0x81e00000

Linux kernel console boot log

[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Linux version 3.18.20 (linux3@linux3) (gcc version 4.9.2 (GCC) ) #1 PREEMPT Thu Aug 10 11:57:07 CST 2017
[    0.000000] CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=10c53c7d
[    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[    0.000000] Machine model: Qualcomm Technologies, Inc. MDM 9607 MTP
[    0.000000] Early serial console at I/O port 0x0 (options '')
[    0.000000] bootconsole [uart0] enabled
[    0.000000] Reserved memory: reserved region for node 'modem_adsp_region@0': base 0x82a00000, size 56 MiB
[    0.000000] Reserved memory: reserved region for node 'external_image_region@0': base 0x87c00000, size 4 MiB
[    0.000000] Removed memory: created DMA memory pool at 0x82a00000, size 56 MiB
[    0.000000] Reserved memory: initialized node modem_adsp_region@0, compatible id removed-dma-pool
[    0.000000] Removed memory: created DMA memory pool at 0x87c00000, size 4 MiB
[    0.000000] Reserved memory: initialized node external_image_region@0, compatible id removed-dma-pool
[    0.000000] cma: Reserved 4 MiB at 0x87800000
[    0.000000] Memory policy: Data cache writeback
[    0.000000] CPU: All CPU(s) started in SVC mode.
[    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 17152
[    0.000000] Kernel command line: noinitrd  rw console=ttyHSL0,115200,n8 androidboot.hardware=qcom ehci-hcd.park=3 msm_rtb.filter=0x37 lpm_levels.sleep_disabled=1  earlycon=msm_hsl_uart,0x78b3000  androidboot.serialno=7e6ba58c androidboot.baseband=msm rootfstype=ubifs rootflags=bulk_read root=ubi0:rootfs ubi.mtd=16
[    0.000000] PID hash table entries: 512 (order: -1, 2048 bytes)
[    0.000000] Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)
[    0.000000] Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)
[    0.000000] Memory: 54792K/69632K available (5830K kernel code, 399K rwdata, 2228K rodata, 276K init, 830K bss, 14840K reserved)
[    0.000000] Virtual kernel memory layout:
[    0.000000]     vector  : 0xffff0000 - 0xffff1000   (   4 kB)
[    0.000000]     fixmap  : 0xffc00000 - 0xfff00000   (3072 kB)
[    0.000000]     vmalloc : 0xc8800000 - 0xff000000   ( 872 MB)
[    0.000000]     lowmem  : 0xc0000000 - 0xc8000000   ( 128 MB)
[    0.000000]     modules : 0xbf000000 - 0xc0000000   (  16 MB)
[    0.000000]       .text : 0xc0008000 - 0xc07e6c38   (8060 kB)
[    0.000000]       .init : 0xc07e7000 - 0xc082c000   ( 276 kB)
[    0.000000]       .data : 0xc082c000 - 0xc088fdc0   ( 400 kB)
[    0.000000]        .bss : 0xc088fe84 - 0xc095f798   ( 831 kB)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] Preemptible hierarchical RCU implementation.
[    0.000000] NR_IRQS:16 nr_irqs:16 16
[    0.000000] GIC CPU mask not found - kernel will fail to boot.
[    0.000000] GIC CPU mask not found - kernel will fail to boot.
[    0.000000] mpm_init_irq_domain(): Cannot find irq controller for qcom,gpio-parent
[    0.000000] MPM 1 irq mapping errored -517
[    0.000000] Architected mmio timer(s) running at 19.20MHz (virt).
[    0.000011] sched_clock: 56 bits at 19MHz, resolution 52ns, wraps every 3579139424256ns
[    0.007975] Switching to timer-based delay loop, resolution 52ns
[    0.013969] Switched to clocksource arch_mem_counter
[    0.019687] Console: colour dummy device 80x30
[    0.023344] Calibrating delay loop (skipped), value calculated using timer frequency.. 38.40 BogoMIPS (lpj=192000)
[    0.033666] pid_max: default: 32768 minimum: 301
[    0.038411] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.044902] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.052445] CPU: Testing write buffer coherency: ok
[    0.057057] Setting up static identity map for 0x8058aac8 - 0x8058ab20
[    0.064242]
[    0.064242] **********************************************************
[    0.071251] **   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **
[    0.077817] **                                                      **
[    0.084302] ** trace_printk() being used. Allocating extra memory.  **
[    0.090781] **                                                      **
[    0.097320] ** This means that this is a DEBUG kernel and it is     **
[    0.103802] ** unsafe for produciton use.                           **
[    0.110339] **                                                      **
[    0.116850] ** If you see this message and you are not debugging    **
[    0.123333] ** the kernel, report this immediately to your vendor!  **
[    0.129870] **                                                      **
[    0.136380] **   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **
[    0.142865] **********************************************************
[    0.150225] MSM Memory Dump base table set up
[    0.153739] MSM Memory Dump apps data table set up
[    0.168125] VFP support v0.3: implementor 41 architecture 2 part 30 variant 7 rev 5
[    0.176332] pinctrl core: initialized pinctrl subsystem
[    0.180930] regulator-dummy: no parameters
[    0.215338] NET: Registered protocol family 16
[    0.220475] DMA: preallocated 256 KiB pool for atomic coherent allocations
[    0.284034] cpuidle: using governor ladder
[    0.314026] cpuidle: using governor menu
[    0.344024] cpuidle: using governor qcom
[    0.355452] msm_watchdog b017000.qcom,wdt: wdog absent resource not present
[    0.361656] msm_watchdog b017000.qcom,wdt: MSM Watchdog Initialized
[    0.371373] irq: no irq domain found for /soc/pinctrl@1000000 !
[    0.381268] spmi_pmic_arb 200f000.qcom,spmi: PMIC Arb Version-2 0x20010000
[    0.389733] platform 4080000.qcom,mss: assigned reserved memory node modem_adsp_region@0
[    0.397409] mem_acc_corner: 0 <--> 0 mV
[    0.401937] hw-breakpoint: found 5 (+1 reserved) breakpoint and 4 watchpoint registers.
[    0.408966] hw-breakpoint: maximum watchpoint size is 8 bytes.
[    0.416287] __of_mpm_init(): MPM driver mapping exists
[    0.420940] msm_rpm_glink_dt_parse: qcom,rpm-glink compatible not matches
[    0.427235] msm_rpm_dev_probe: APSS-RPM communication over SMD
[    0.432977] smd_open() before smd_init()
[    0.437544] msm_mpm_dev_probe(): Cannot get clk resource for XO: -517
[    0.445730] smd_channel_probe_now: allocation table not initialized
[    0.453100] mdm9607_s1: 1050 <--> 1350 mV at 1225 mV normal idle
[    0.458566] spm_regulator_probe: name=mdm9607_s1, range=LV, voltage=1225000 uV, mode=AUTO, step rate=4800 uV/us
[    0.468817] cpr_efuse_init: apc_corner: efuse_addr = 0x000a4000 (len=0x1000)
[    0.475353] cpr_read_fuse_revision: apc_corner: fuse revision = 2
[    0.481345] cpr_parse_speed_bin_fuse: apc_corner: [row: 37]: 0x79e8bd327e6ba58c, speed_bits = 4
[    0.490124] cpr_pvs_init: apc_corner: pvs voltage: [1050000 1100000 1275000] uV
[    0.497342] cpr_pvs_init: apc_corner: ceiling voltage: [1050000 1225000 1350000] uV
[    0.504979] cpr_pvs_init: apc_corner: floor voltage: [1050000 1050000 1150000] uV
[    0.513125] i2c-msm-v2 78b8000.i2c: probing driver i2c-msm-v2
[    0.518335] i2c-msm-v2 78b8000.i2c: error on clk_get(core_clk):-517
[    0.524478] i2c-msm-v2 78b8000.i2c: error probe() failed with err:-517
[    0.531111] i2c-msm-v2 78b7000.i2c: probing driver i2c-msm-v2
[    0.536788] i2c-msm-v2 78b7000.i2c: error on clk_get(core_clk):-517
[    0.542886] i2c-msm-v2 78b7000.i2c: error probe() failed with err:-517
[    0.549618] i2c-msm-v2 78b9000.i2c: probing driver i2c-msm-v2
[    0.555202] i2c-msm-v2 78b9000.i2c: error on clk_get(core_clk):-517
[    0.561374] i2c-msm-v2 78b9000.i2c: error probe() failed with err:-517
[    0.570613] msm-thermal soc:qcom,msm-thermal: msm_thermal:Failed reading node=/soc/qcom,msm-thermal, key=qcom,core-limit-temp. err=-22. KTM continues
[    0.583049] msm-thermal soc:qcom,msm-thermal: probe_therm_reset:Failed reading node=/soc/qcom,msm-thermal, key=qcom,therm-reset-temp err=-22. KTM continues
[    0.596926] msm_thermal:msm_thermal_dev_probe Failed reading node=/soc/qcom,msm-thermal, key=qcom,online-hotplug-core. err:-517
[    0.609370] sps:sps is ready.
[    0.613137] msm_rpm_glink_dt_parse: qcom,rpm-glink compatible not matches
[    0.619020] msm_rpm_dev_probe: APSS-RPM communication over SMD
[    0.625773] mdm9607_s2: 750 <--> 1275 mV at 750 mV normal idle
[    0.631584] mdm9607_s3_level: 0 <--> 0 mV at 0 mV normal idle
[    0.637085] mdm9607_s3_level_ao: 0 <--> 0 mV at 0 mV normal idle
[    0.643092] mdm9607_s3_floor_level: 0 <--> 0 mV at 0 mV normal idle
[    0.649512] mdm9607_s3_level_so: 0 <--> 0 mV at 0 mV normal idle
[    0.655750] mdm9607_s4: 1800 <--> 1950 mV at 1800 mV normal idle
[    0.661791] mdm9607_l1: 1250 mV normal idle
[    0.666090] mdm9607_l2: 1800 mV normal idle
[    0.670276] mdm9607_l3: 1800 mV normal idle
[    0.674541] mdm9607_l4: 3075 mV normal idle
[    0.678743] mdm9607_l5: 1700 <--> 3050 mV at 1700 mV normal idle
[    0.684904] mdm9607_l6: 1700 <--> 3050 mV at 1700 mV normal idle
[    0.690892] mdm9607_l7: 1700 <--> 1900 mV at 1700 mV normal idle
[    0.697036] mdm9607_l8: 1800 mV normal idle
[    0.701238] mdm9607_l9: 1200 <--> 1250 mV at 1200 mV normal idle
[    0.707367] mdm9607_l10: 1050 mV normal idle
[    0.711662] mdm9607_l11: 1800 mV normal idle
[    0.716089] mdm9607_l12_level: 0 <--> 0 mV at 0 mV normal idle
[    0.721717] mdm9607_l12_level_ao: 0 <--> 0 mV at 0 mV normal idle
[    0.727946] mdm9607_l12_level_so: 0 <--> 0 mV at 0 mV normal idle
[    0.734099] mdm9607_l12_floor_lebel: 0 <--> 0 mV at 0 mV normal idle
[    0.740706] mdm9607_l13: 1800 <--> 2850 mV at 2850 mV normal idle
[    0.746883] mdm9607_l14: 2650 <--> 3000 mV at 2650 mV normal idle
[    0.752515] msm_mpm_dev_probe(): Cannot get clk resource for XO: -517
[    0.759036] cpr_efuse_init: apc_corner: efuse_addr = 0x000a4000 (len=0x1000)
[    0.765807] cpr_read_fuse_revision: apc_corner: fuse revision = 2
[    0.771809] cpr_parse_speed_bin_fuse: apc_corner: [row: 37]: 0x79e8bd327e6ba58c, speed_bits = 4
[    0.780586] cpr_pvs_init: apc_corner: pvs voltage: [1050000 1100000 1275000] uV
[    0.787808] cpr_pvs_init: apc_corner: ceiling voltage: [1050000 1225000 1350000] uV
[    0.795443] cpr_pvs_init: apc_corner: floor voltage: [1050000 1050000 1150000] uV
[    0.803094] cpr_init_cpr_parameters: apc_corner: up threshold = 2, down threshold = 3
[    0.810752] cpr_init_cpr_parameters: apc_corner: CPR is enabled by default.
[    0.817687] cpr_init_cpr_efuse: apc_corner: [row:65] = 0x15000277277383
[    0.824272] cpr_init_cpr_efuse: apc_corner: CPR disable fuse = 0
[    0.830225] cpr_init_cpr_efuse: apc_corner: Corner[1]: ro_sel = 0, target quot = 631
[    0.837976] cpr_init_cpr_efuse: apc_corner: Corner[2]: ro_sel = 0, target quot = 631
[    0.845703] cpr_init_cpr_efuse: apc_corner: Corner[3]: ro_sel = 0, target quot = 899
[    0.853592] cpr_config: apc_corner: Timer count: 0x17700 (for 5000 us)
[    0.860426] apc_corner: 0 <--> 0 mV
[    0.864044] i2c-msm-v2 78b8000.i2c: probing driver i2c-msm-v2
[    0.869261] i2c-msm-v2 78b8000.i2c: error on clk_get(core_clk):-517
[    0.875492] i2c-msm-v2 78b8000.i2c: error probe() failed with err:-517
[    0.882225] i2c-msm-v2 78b7000.i2c: probing driver i2c-msm-v2
[    0.887775] i2c-msm-v2 78b7000.i2c: error on clk_get(core_clk):-517
[    0.893941] i2c-msm-v2 78b7000.i2c: error probe() failed with err:-517
[    0.900719] i2c-msm-v2 78b9000.i2c: probing driver i2c-msm-v2
[    0.906256] i2c-msm-v2 78b9000.i2c: error on clk_get(core_clk):-517
[    0.912430] i2c-msm-v2 78b9000.i2c: error probe() failed with err:-517
[    0.919472] msm-thermal soc:qcom,msm-thermal: msm_thermal:Failed reading node=/soc/qcom,msm-thermal, key=qcom,core-limit-temp. err=-22. KTM continues
[    0.932372] msm-thermal soc:qcom,msm-thermal: probe_therm_reset:Failed reading node=/soc/qcom,msm-thermal,
key=qcom,therm-reset-temp err=-22. KTM continues
[    0.946361] msm_thermal:get_kernel_cluster_info CPU0 topology not initialized.
[    0.953824] cpu cpu0: dev_pm_opp_get_opp_count: device OPP not found (-19)
[    0.960300] msm_thermal:get_cpu_freq_plan_len Error reading CPU0 freq table len. error:-19
[    0.968533] msm_thermal:vdd_restriction_reg_init Defer vdd rstr freq init.
[    0.975846] cpu cpu0: dev_pm_opp_get_opp_count: device OPP not found (-19)
[    0.982219] msm_thermal:get_cpu_freq_plan_len Error reading CPU0 freq table len. error:-19
[    0.991378] cpu cpu0: dev_pm_opp_get_opp_count: device OPP not found (-19)
[    0.997544] msm_thermal:get_cpu_freq_plan_len Error reading CPU0 freq table len. error:-19
[    1.013642] qcom,gcc-mdm9607 1800000.qcom,gcc: Registered GCC clocks
[    1.019451] clock-a7 b010008.qcom,clock-a7: Speed bin: 4 PVS Version: 0
[    1.025693] a7ssmux: set OPP pair(400000000 Hz: 1 uV) on cpu0
[    1.031314] a7ssmux: set OPP pair(1305600000 Hz: 7 uV) on cpu0
[    1.038805] i2c-msm-v2 78b8000.i2c: probing driver i2c-msm-v2
[    1.043587] AXI: msm_bus_scale_register_client(): msm_bus_scale_register_client: Bus driver not ready.
[    1.052935] i2c-msm-v2 78b8000.i2c: msm_bus_scale_register_client(mstr-id:86):0 (not a problem)
[    1.062006] irq: no irq domain found for /soc/wcd9xxx-irq !
[    1.069884] i2c-msm-v2 78b7000.i2c: probing driver i2c-msm-v2
[    1.074814] AXI: msm_bus_scale_register_client(): msm_bus_scale_register_client: Bus driver not ready.
[    1.083716] i2c-msm-v2 78b7000.i2c: msm_bus_scale_register_client(mstr-id:86):0 (not a problem)
[    1.093850] i2c-msm-v2 78b9000.i2c: probing driver i2c-msm-v2
[    1.098889] AXI: msm_bus_scale_register_client(): msm_bus_scale_register_client: Bus driver not ready.
[    1.107779] i2c-msm-v2 78b9000.i2c: msm_bus_scale_register_client(mstr-id:86):0 (not a problem)
[    1.167871] KPI: Bootloader start count = 24097
[    1.171364] KPI: Bootloader end count = 48481
[    1.175855] KPI: Bootloader display count = 3884474147
[    1.180825] KPI: Bootloader load kernel count = 16420
[    1.185905] KPI: Kernel MPM timestamp = 105728
[    1.190286] KPI: Kernel MPM Clock frequency = 32768
[    1.195209] socinfo_print: v0.10, id=297, ver=1.0, raw_id=72, raw_ver=0, hw_plat=8, hw_plat_ver=65536
[    1.195209]  accessory_chip=0, hw_plat_subtype=0, pmic_model=65539, pmic_die_revision=131074 foundry_id=0 serial_number=2120983948
[    1.216731] sdcard_ext_vreg: no parameters
[    1.220555] rome_vreg: no parameters
[    1.224133] emac_lan_vreg: no parameters
[    1.228177] usbcore: registered new interface driver usbfs
[    1.233156] usbcore: registered new interface driver hub
[    1.238578] usbcore: registered new device driver usb
[    1.244507] cpufreq: driver msm up and running
[    1.248425] ION heap system created
[    1.251895] msm_bus_fabric_init_driver
[    1.262563] qcom,qpnp-power-on qpnp-power-on-c7303800: PMIC@SID0 Power-on reason: Triggered from PON1 (secondary PMIC) and 'cold' boot
[    1.273747] qcom,qpnp-power-on qpnp-power-on-c7303800: PMIC@SID0: Power-off reason: Triggered from UVLO (Under Voltage Lock Out)
[    1.285430] input: qpnp_pon as /devices/virtual/input/input0
[    1.291246] PMIC@SID0: PM8019 v2.2 options: 3, 2, 2, 2
[    1.296706] Advanced Linux Sound Architecture Driver Initialized.
[    1.302493] Add group failed
[    1.305291] cfg80211: Calling CRDA to update world regulatory domain
[    1.311216] cfg80211: World regulatory domain updated:
[    1.317109] Switched to clocksource arch_mem_counter
[    1.334091] cfg80211:  DFS Master region: unset
[    1.337418] cfg80211:   (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
[    1.354087] cfg80211:   (2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A, 2000 mBm), (N/A)
[    1.361055] cfg80211:   (2457000 KHz - 2482000 KHz @ 40000 KHz), (N/A, 2000 mBm), (N/A)
[    1.370545] NET: Registered protocol family 2
[    1.374082] cfg80211:   (2474000 KHz - 2494000 KHz @ 20000 KHz), (N/A, 2000 mBm), (N/A)
[    1.381851] cfg80211:   (5170000 KHz - 5250000 KHz @ 80000 KHz), (N/A, 2000 mBm), (N/A)
[    1.389876] cfg80211:   (5250000 KHz - 5330000 KHz @ 80000 KHz), (N/A, 2000 mBm), (N/A)
[    1.397857] cfg80211:   (5490000 KHz - 5710000 KHz @ 80000 KHz), (N/A, 2000 mBm), (N/A)
[    1.405841] cfg80211:   (5735000 KHz - 5835000 KHz @ 80000 KHz), (N/A, 2000 mBm), (N/A)
[    1.413795] cfg80211:   (57240000 KHz - 63720000 KHz @ 2160000 KHz), (N/A, 0 mBm), (N/A)
[    1.422355] TCP established hash table entries: 1024 (order: 0, 4096 bytes)
[    1.428921] TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
[    1.435192] TCP: Hash tables configured (established 1024 bind 1024)
[    1.441528] TCP: reno registered
[    1.444738] UDP hash table entries: 256 (order: 0, 4096 bytes)
[    1.450521] UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
[    1.456950] NET: Registered protocol family 1
[    1.462779] futex hash table entries: 256 (order: -1, 3072 bytes)
[    1.474555] msgmni has been set to 115
[    1.478551] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 251)
[    1.485041] io scheduler noop registered
[    1.488818] io scheduler deadline registered
[    1.493200] io scheduler cfq registered (default)
[    1.502142] msm_rpm_log_probe: OK
[    1.506717] msm_serial_hs module loaded
[    1.509803] msm_serial_hsl_probe: detected port #0 (ttyHSL0)
[    1.515324] AXI: get_pdata(): Error: Client name not found
[    1.520626] AXI: msm_bus_cl_get_pdata(): client has to provide missing entry for successful registration
[    1.530171] msm_serial_hsl_probe: Bus scaling is disabled                      [    1.074814] AXI: msm_bus_scale_register_client(): msm_bus_scale_register_client: Bus driver not ready.
[    1.083716] i2c-msm-v2 78b7000.i2c: msm_bus_scale_register_client(mstr-id:86):0 (not a problem)
[    1.093850] i2c-msm-v2 78b9000.i2c: probing driver i2c-msm-v2
[    1.098889] AXI: msm_bus_scale_register_client(): msm_bus_scale_register_client: Bus driver not ready.
[    1.107779] i2c-msm-v2 78b9000.i2c: msm_bus_scale_register_client(mstr-id:86):0 (not a problem)
[    1.167871] KPI: Bootloader start count = 24097
[    1.171364] KPI: Bootloader end count = 48481
[    1.175855] KPI: Bootloader display count = 3884474147
[    1.180825] KPI: Bootloader load kernel count = 16420
[    1.185905] KPI: Kernel MPM timestamp = 105728
[    1.190286] KPI: Kernel MPM Clock frequency = 32768
[    1.195209] socinfo_print: v0.10, id=297, ver=1.0, raw_id=72, raw_ver=0, hw_plat=8, hw_plat_ver=65536
[    1.195209]  accessory_chip=0, hw_plat_subtype=0, pmic_model=65539, pmic_die_revision=131074 foundry_id=0 serial_number=2120983948
[    1.216731] sdcard_ext_vreg: no parameters
[    1.220555] rome_vreg: no parameters
[    1.224133] emac_lan_vreg: no parameters
[    1.228177] usbcore: registered new interface driver usbfs
[    1.233156] usbcore: registered new interface driver hub
[    1.238578] usbcore: registered new device driver usb
[    1.244507] cpufreq: driver msm up and running
[    1.248425] ION heap system created
[    1.251895] msm_bus_fabric_init_driver
[    1.262563] qcom,qpnp-power-on qpnp-power-on-c7303800: PMIC@SID0 Power-on reason: Triggered from PON1 (secondary PMIC) and 'cold' boot
[    1.273747] qcom,qpnp-power-on qpnp-power-on-c7303800: PMIC@SID0: Power-off reason: Triggered from UVLO (Under Voltage Lock Out)
[    1.285430] input: qpnp_pon as /devices/virtual/input/input0
[    1.291246] PMIC@SID0: PM8019 v2.2 options: 3, 2, 2, 2
[    1.296706] Advanced Linux Sound Architecture Driver Initialized.
[    1.302493] Add group failed
[    1.305291] cfg80211: Calling CRDA to update world regulatory domain
[    1.311216] cfg80211: World regulatory domain updated:
[    1.317109] Switched to clocksource arch_mem_counter
[    1.334091] cfg80211:  DFS Master region: unset
[    1.337418] cfg80211:   (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
[    1.354087] cfg80211:   (2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A, 2000 mBm), (N/A)
[    1.361055] cfg80211:   (2457000 KHz - 2482000 KHz @ 40000 KHz), (N/A, 2000 mBm), (N/A)
[    1.370545] NET: Registered protocol family 2
[    1.374082] cfg80211:   (2474000 KHz - 2494000 KHz @ 20000 KHz), (N/A, 2000 mBm), (N/A)
[    1.381851] cfg80211:   (5170000 KHz - 5250000 KHz @ 80000 KHz), (N/A, 2000 mBm), (N/A)
[    1.389876] cfg80211:   (5250000 KHz - 5330000 KHz @ 80000 KHz), (N/A, 2000 mBm), (N/A)
[    1.397857] cfg80211:   (5490000 KHz - 5710000 KHz @ 80000 KHz), (N/A, 2000 mBm), (N/A)
[    1.405841] cfg80211:   (5735000 KHz - 5835000 KHz @ 80000 KHz), (N/A, 2000 mBm), (N/A)
[    1.413795] cfg80211:   (57240000 KHz - 63720000 KHz @ 2160000 KHz), (N/A, 0 mBm), (N/A)
[    1.422355] TCP established hash table entries: 1024 (order: 0, 4096 bytes)
[    1.428921] TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
[    1.435192] TCP: Hash tables configured (established 1024 bind 1024)
[    1.441528] TCP: reno registered
[    1.444738] UDP hash table entries: 256 (order: 0, 4096 bytes)
[    1.450521] UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
[    1.456950] NET: Registered protocol family 1
[    1.462779] futex hash table entries: 256 (order: -1, 3072 bytes)
[    1.474555] msgmni has been set to 115
[    1.478551] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 251)
[    1.485041] io scheduler noop registered
[    1.488818] io scheduler deadline registered
[    1.493200] io scheduler cfq registered (default)
[    1.502142] msm_rpm_log_probe: OK
[    1.506717] msm_serial_hs module loaded
[    1.509803] msm_serial_hsl_probe: detected port #0 (ttyHSL0)
[    1.515324] AXI: get_pdata(): Error: Client name not found
[    1.520626] AXI: msm_bus_cl_get_pdata(): client has to provide missing entry for successful registration
[    1.530171] msm_serial_hsl_probe: Bus scaling is disabled
[    1.535696] 78b3000.serial: ttyHSL0 at MMIO 0x78b3000 (irq = 153, base_baud = 460800 [    1.544155] msm_hsl_console_setup: console setup on port #0
[    1.548727] console [ttyHSL0] enabled
[    1.548727] console [ttyHSL0] enabled
[    1.556014] bootconsole [uart0] disabled
[    1.556014] bootconsole [uart0] disabled
[    1.564212] msm_serial_hsl_init: driver initialized
[    1.578450] brd: module loaded
[    1.582920] loop: module loaded
[    1.589183] sps: BAM device 0x07984000 is not registered yet.
[    1.594234] sps:BAM 0x07984000 is registered.
[    1.598072] msm_nand_bam_init: msm_nand_bam_init: BAM device registered: bam_handle 0xc69f6400
[    1.607103] sps:BAM 0x07984000 (va:0xc89a0000) enabled: ver:0x18, number of pipes:7
[    1.616588] msm_nand_parse_smem_ptable: Parsing partition table info from SMEM
[    1.622805] msm_nand_parse_smem_ptable: SMEM partition table found: ver: 4 len: 17
[    1.630391] msm_nand_version_check: nand_major:1, nand_minor:5, qpic_major:1, qpic_minor:5
[    1.638642] msm_nand_scan: NAND Id: 0x1590aa98 Buswidth: 8Bits Density: 256 MByte
[    1.646069] msm_nand_scan: pagesize: 2048 Erasesize: 131072 oobsize: 128 (in Bytes)
[    1.653676] msm_nand_scan: BCH ECC: 8 Bit
[    1.657710] msm_nand_scan: CFG0: 0x290408c0,           CFG1: 0x0804715c
[    1.657710]             RAWCFG0: 0x2b8400c0,        RAWCFG1: 0x0005055d
[    1.657710]           ECCBUFCFG: 0x00000203,      ECCBCHCFG: 0x42040d10
[    1.657710]           RAWECCCFG: 0x42000d11, BAD BLOCK BYTE: 0x000001c5
[    1.684101] Creating 17 MTD partitions on "7980000.nand":
[    1.689447] 0x000000000000-0x000000140000 : "sbl"
[    1.694867] 0x000000140000-0x000000280000 : "mibib"
[    1.699560] 0x000000280000-0x000000e80000 : "efs2"
[    1.704408] 0x000000e80000-0x000000f40000 : "tz"
[    1.708934] 0x000000f40000-0x000000fa0000 : "rpm"
[    1.713625] 0x000000fa0000-0x000001000000 : "aboot"
[    1.718582] 0x000001000000-0x0000017e0000 : "boot"
[    1.723281] 0x0000017e0000-0x000002820000 : "scrub"
[    1.728174] 0x000002820000-0x000005020000 : "modem"
[    1.732968] 0x000005020000-0x000005420000 : "rfbackup"
[    1.738156] 0x000005420000-0x000005820000 : "oem"
[    1.742770] 0x000005820000-0x000005f00000 : "recovery"
[    1.747972] 0x000005f00000-0x000009100000 : "cache"
[    1.752787] 0x000009100000-0x000009a40000 : "recoveryfs"
[    1.758389] 0x000009a40000-0x00000aa40000 : "cdrom"
[    1.762967] 0x00000aa40000-0x00000ba40000 : "jrdresource"
[    1.768407] 0x00000ba40000-0x000010000000 : "system"
[    1.773239] msm_nand_probe: NANDc phys addr 0x7980000, BAM phys addr 0x7984000, BAM IRQ 164
[    1.781074] msm_nand_probe: Allocated DMA buffer at virt_addr 0xc7840000, phys_addr 0x87840000
[    1.791872] PPP generic driver version 2.4.2
[    1.801126] cnss_sdio 87a00000.qcom,cnss-sdio: CNSS SDIO Driver registered
[    1.807554] msm_otg 78d9000.usb: msm_otg probe
[    1.813333] msm_otg 78d9000.usb: OTG regs = c88f8000
[    1.820702] gbridge_init: gbridge_init successs.
[    1.826344] msm_otg 78d9000.usb: phy_reset: success
[    1.830294] qcom,qpnp-rtc qpnp-rtc-c7307000: rtc core: registered qpnp_rtc as rtc0
[    1.838474] i2c /dev entries driver
[    1.842459] unable to find DT imem DLOAD mode node
[    1.846588] unable to find DT imem EDLOAD mode node
[    1.851332] unable to find DT imem dload-type node
[    1.856921] bq24295-charger 4-006b: bq24295 probe enter
[    1.861161] qcom,iterm-ma = 128
[    1.864476] bq24295_otg_vreg: no parameters
[    1.868502] charger_core_register: Charger Core Version 5.0.0(Built at 20151202-21:36)!
[    1.877007] i2c-msm-v2 78b8000.i2c: msm_bus_scale_register_client(mstr-id:86):0x3 (ok)
[    1.885559] bq24295-charger 4-006b: bq24295_set_bhot_mode 3
[    1.890150] bq24295-charger 4-006b: power_good is 1,vbus_stat is 2
[    1.896588] bq24295-charger 4-006b: bq24295_set_thermal_threshold 100
[    1.902952] bq24295-charger 4-006b: bq24295_set_sys_min 3700
[    1.908639] bq24295-charger 4-006b: bq24295_set_max_target_voltage 4150
[    1.915223] bq24295-charger 4-006b: bq24295_set_recharge_threshold 300
[    1.922119] bq24295-charger 4-006b: bq24295_set_terminal_current_limit iterm_disabled=0, iterm_ma=128
[    1.930917] bq24295-charger 4-006b: bq24295_set_precharge_current_limit bdi->prech_cur=128
[    1.940038] bq24295-charger 4-006b: bq24295_set_safty_timer 0
[    1.945088] bq24295-charger 4-006b: bq24295_set_input_voltage_limit 4520
[    1.972949] sdhci: Secure Digital Host Controller Interface driver
[    1.978151] sdhci: Copyright(c) Pierre Ossman
[    1.982441] sdhci-pltfm: SDHCI platform and OF driver helper
[    1.989092] sdhci_msm 7824900.sdhci: sdhci_msm_probe: ICE device is not enabled
[    1.995473] sdhci_msm 7824900.sdhci: No vreg data found for vdd
[    2.001530] sdhci_msm 7824900.sdhci: sdhci_msm_pm_qos_parse_irq: error -22 reading irq cpu
[    2.009809] sdhci_msm 7824900.sdhci: sdhci_msm_pm_qos_parse: PM QoS voting for IRQ will be disabled
[    2.018600] sdhci_msm 7824900.sdhci: sdhci_msm_pm_qos_parse: PM QoS voting for cpu group will be disabled
[    2.030541] sdhci_msm 7824900.sdhci: sdhci_msm_probe: sdiowakeup_irq = 353
[    2.036867] sdhci_msm 7824900.sdhci: No vmmc regulator found
[    2.042027] sdhci_msm 7824900.sdhci: No vqmmc regulator found
[    2.048266] mmc0: SDHCI controller on 7824900.sdhci [7824900.sdhci] using 32-bit ADMA in legacy mode
[    2.080401] Welcome to pca955x_probe!!
[    2.084362] leds-pca955x 3-0020: leds-pca955x: Using pca9555 16-bit LED driver at slave address 0x20
[    2.095400] sdhci_msm 7824900.sdhci: card claims to support voltages below defined range
[    2.103125] i2c-msm-v2 78b7000.i2c: msm_bus_scale_register_client(mstr-id:86):0x5 (ok)
[    2.114183] msm_otg 78d9000.usb: Avail curr from USB = 1500
[    2.120251] come to USB_SDP_CHARGER!
[    2.123215] Welcome to sn3199_probe!
[    2.126718] leds-sn3199 5-0064: leds-sn3199: Using sn3199 9-bit LED driver at slave address 0x64
[    2.136511] sn3199->led_en_gpio=21
[    2.139143] i2c-msm-v2 78b9000.i2c: msm_bus_scale_register_client(mstr-id:86):0x6 (ok)
[    2.150207] usbcore: registered new interface driver usbhid
[    2.154864] usbhid: USB HID core driver
[    2.159825] sps:BAM 0x078c4000 is registered.
[    2.163573] bimc-bwmon 408000.qcom,cpu-bwmon: BW HWmon governor registered.
[    2.171080] devfreq soc:qcom,cpubw: Couldn't update frequency transition information.
[    2.178513] coresight-fuse a601c.fuse: QPDI fuse not specified
[    2.184242] coresight-fuse a601c.fuse: Fuse initialized
[    2.192407] coresight-csr 6001000.csr: CSR initialized
[    2.197263] coresight-tmc 6026000.tmc: Byte Counter feature enabled
[    2.203204] sps:BAM 0x06084000 is registered.
[    2.207301] coresight-tmc 6026000.tmc: TMC initialized
[    2.212681] coresight-tmc 6025000.tmc: TMC initialized
[    2.220071] nidnt boot config: 0
[    2.224563] mmc0: new ultra high speed SDR50 SDIO card at address 0001
[    2.231120] coresight-tpiu 6020000.tpiu: NIDnT on SDCARD only mode
[    2.236440] coresight-tpiu 6020000.tpiu: TPIU initialized
[    2.242808] coresight-replicator 6024000.replicator: REPLICATOR initialized
[    2.249372] coresight-stm 6002000.stm: STM initialized
[    2.255034] coresight-hwevent 606c000.hwevent: Hardware Event driver initialized
[    2.262312] Netfilter messages via NETLINK v0.30.
[    2.266306] nf_conntrack version 0.5.0 (920 buckets, 3680 max)
[    2.272312] ctnetlink v0.93: registering with nfnetlink.
[    2.277565] ip_set: protocol 6
[    2.280568] ip_tables: (C) 2000-2006 Netfilter Core Team
[    2.285723] arp_tables: (C) 2002 David S. Miller
[    2.290146] TCP: cubic registered
[    2.293915] NET: Registered protocol family 10
[    2.298740] ip6_tables: (C) 2000-2006 Netfilter Core Team
[    2.303407] sit: IPv6 over IPv4 tunneling driver
[    2.308481] NET: Registered protocol family 17
[    2.312340] bridge: automatic filtering via arp/ip/ip6tables has been deprecated. Update your scripts to load br_netfilter if you need this.
[    2.325094] Bridge firewalling registered
[    2.328930] Ebtables v2.0 registered
[    2.333260] NET: Registered protocol family 27
[    2.341362] battery_core_register: Battery Core Version 5.0.0(Built at 20151202-21:36)!
[    2.348466] pmu_battery_probe: vbat_channel=21, tbat_channel=17
[    2.420236] ubi0: attaching mtd16
[    2.723941] ubi0: scanning is finished
[    2.732997] ubi0: attached mtd16 (name "system", size 69 MiB)
[    2.737783] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes
[    2.744601] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048
[    2.751333] ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096
[    2.758540] ubi0: good PEBs: 556, bad PEBs: 2, corrupted PEBs: 0
[    2.764305] ubi0: user volume: 3, internal volumes: 1, max. volumes count: 128
[    2.771476] ubi0: max/mean erase counter: 192/64, WL threshold: 4096, image sequence number: 35657280
[    2.780708] ubi0: available PEBs: 0, total reserved PEBs: 556, PEBs reserved for bad PEB handling: 38
[    2.789921] ubi0: background thread "ubi_bgt0d" started, PID 96
[    2.796395] android_bind cdev: 0xC6583E80, name: ci13xxx_msm
[    2.801508] file system registered
[    2.804974] mbim_init: initialize 1 instances
[    2.809228] mbim_init: Initialized 1 ports
[    2.815074] rndis_qc_init: initialize rndis QC instance
[    2.819713] jrd device_desc.bcdDevice: [0x0242]
[    2.823779] android_bind scheduled usb start work: name: ci13xxx_msm
[    2.830230] android_usb gadget: android_usb ready
[    2.834845] msm_hsusb msm_hsusb: [ci13xxx_start] hw_ep_max = 32
[    2.840741] msm_hsusb msm_hsusb: CI13XXX_CONTROLLER_RESET_EVENT received
[    2.847433] msm_hsusb msm_hsusb: CI13XXX_CONTROLLER_UDC_STARTED_EVENT received
[    2.855851] input: gpio-keys as /devices/soc:gpio_keys/input/input1
[    2.861452] qcom,qpnp-rtc qpnp-rtc-c7307000: setting system clock to 1970-01-01 06:36:41 UTC (23801)
[    2.870315] open file error /usb_conf/usb_config.ini
[    2.876412] jrd_usb_start_work open file erro /usb_conf/usb_config.ini, retry_count:0
[    2.884324] parse_legacy_cluster_params(): Ignoring cluster params
[    2.889468] ------------[ cut here ]------------
[    2.894186] WARNING: CPU: 0 PID: 1 at /home/linux3/jrd/yanping.an/ee40/0810/MDM9607.LE.1.0-00130/apps_proc/oe-core/build/tmp-glibc/work-shared/mdm9607/kernel-source/drivers/cpuidle/lpm-levels-of.c:739 parse_cluster+0xb50/0xcb4()
[    2.914366] Modules linked in:
[    2.917339] CPU: 0 PID: 1 Comm: swapper Not tainted 3.18.20 #1
[    2.923171] [<c00132ac>] (unwind_backtrace) from [<c0011460>] (show_stack+0x10/0x14)
[    2.931092] [<c0011460>] (show_stack) from [<c001c6ac>] (warn_slowpath_common+0x68/0x88)
[    2.939175] [<c001c6ac>] (warn_slowpath_common) from [<c001c75c>] (warn_slowpath_null+0x18/0x20)
[    2.947895] [<c001c75c>] (warn_slowpath_null) from [<c034e180>] (parse_cluster+0xb50/0xcb4)
[    2.956189] [<c034e180>] (parse_cluster) from [<c034b6b4>] (lpm_probe+0xc/0x1d4)
[    2.963527] [<c034b6b4>] (lpm_probe) from [<c024857c>] (platform_drv_probe+0x30/0x7c)
[    2.971380] [<c024857c>] (platform_drv_probe) from [<c0246d54>] (driver_probe_device+0xb8/0x1e8)
[    2.980118] [<c0246d54>] (driver_probe_device) from [<c0246f30>] (__driver_attach+0x68/0x8c)
[    2.988467] [<c0246f30>] (__driver_attach) from [<c02455d0>] (bus_for_each_dev+0x6c/0x90)
[    2.996626] [<c02455d0>] (bus_for_each_dev) from [<c02465a4>] (bus_add_driver+0xe0/0x1c8)
[    3.004786] [<c02465a4>] (bus_add_driver) from [<c02477bc>] (driver_register+0x9c/0xe0)
[    3.012739] [<c02477bc>] (driver_register) from [<c080c3d8>] (lpm_levels_module_init+0x14/0x38)
[    3.021459] [<c080c3d8>] (lpm_levels_module_init) from [<c0008980>] (do_one_initcall+0xf8/0x1a0)
[    3.030217] [<c0008980>] (do_one_initcall) from [<c07e7d4c>] (kernel_init_freeable+0xf0/0x1b0)
[    3.038818] [<c07e7d4c>] (kernel_init_freeable) from [<c0582d48>] (kernel_init+0x8/0xe4)
[    3.046888] [<c0582d48>] (kernel_init) from [<c000dda0>] (ret_from_fork+0x14/0x34)
[    3.054432] ---[ end trace e9ec50b1ec4c8f73 ]---
[    3.059012] ------------[ cut here ]------------
[    3.063604] WARNING: CPU: 0 PID: 1 at /home/linux3/jrd/yanping.an/ee40/0810/MDM9607.LE.1.0-00130/apps_proc/oe-core/build/tmp-glibc/work-shared/mdm9607/kernel-source/drivers/cpuidle/lpm-levels-of.c:739 parse_cluster+0xb50/0xcb4()
[    3.083858] Modules linked in:
[    3.086870] CPU: 0 PID: 1 Comm: swapper Tainted: G        W      3.18.20 #1
[    3.093814] [<c00132ac>] (unwind_backtrace) from [<c0011460>] (show_stack+0x10/0x14)
[    3.101575] [<c0011460>] (show_stack) from [<c001c6ac>] (warn_slowpath_common+0x68/0x88)
[    3.109641] [<c001c6ac>] (warn_slowpath_common) from [<c001c75c>] (warn_slowpath_null+0x18/0x20)
[    3.118412] [<c001c75c>] (warn_slowpath_null) from [<c034e180>] (parse_cluster+0xb50/0xcb4)
[    3.126745] [<c034e180>] (parse_cluster) from [<c034b6b4>] (lpm_probe+0xc/0x1d4)
[    3.134126] [<c034b6b4>] (lpm_probe) from [<c024857c>] (platform_drv_probe+0x30/0x7c)
[    3.141906] [<c024857c>] (platform_drv_probe) from [<c0246d54>] (driver_probe_device+0xb8/0x1e8)
[    3.150702] [<c0246d54>] (driver_probe_device) from [<c0246f30>] (__driver_attach+0x68/0x8c)
[    3.159120] [<c0246f30>] (__driver_attach) from [<c02455d0>] (bus_for_each_dev+0x6c/0x90)
[    3.167285] [<c02455d0>] (bus_for_each_dev) from [<c02465a4>] (bus_add_driver+0xe0/0x1c8)
[    3.175444] [<c02465a4>] (bus_add_driver) from [<c02477bc>] (driver_register+0x9c/0xe0)
[    3.183398] [<c02477bc>] (driver_register) from [<c080c3d8>] (lpm_levels_module_init+0x14/0x38)
[    3.192107] [<c080c3d8>] (lpm_levels_module_init) from [<c0008980>] (do_one_initcall+0xf8/0x1a0)
[    3.200877] [<c0008980>] (do_one_initcall) from [<c07e7d4c>] (kernel_init_freeable+0xf0/0x1b0)
[    3.209475] [<c07e7d4c>] (kernel_init_freeable) from [<c0582d48>] (kernel_init+0x8/0xe4)
[    3.217542] [<c0582d48>] (kernel_init) from [<c000dda0>] (ret_from_fork+0x14/0x34)
[    3.225090] ---[ end trace e9ec50b1ec4c8f74 ]---
[    3.229667] /soc/qcom,lpm-levels/qcom,pm-cluster@0: No CPU phandle, assuming single cluster
[    3.239954] qcom,cc-debug-mdm9607 1800000.qcom,debug: Registered Debug Mux successfully
[    3.247619] emac_lan_vreg: disabling
[    3.250507] mem_acc_corner: disabling
[    3.254196] clock_late_init: Removing enables held for handed-off clocks
[    3.262690] ALSA device list:
[    3.264732]   No soundcard [    3.274083] UBIFS (ubi0:0): background thread "ubifs_bgt0_0" started, PID 102
[    3.305224] UBIFS (ubi0:0): recovery needed
[    3.466156] UBIFS (ubi0:0): recovery completed
[    3.469627] UBIFS (ubi0:0): UBIFS: mounted UBI device 0, volume 0, name "rootfs"
[    3.476987] UBIFS (ubi0:0): LEB size: 126976 bytes (124 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes
[    3.486876] UBIFS (ubi0:0): FS size: 45838336 bytes (43 MiB, 361 LEBs), journal size 9023488 bytes (8 MiB, 72 LEBs)
[    3.497417] UBIFS (ubi0:0): reserved for root: 0 bytes (0 KiB)
[    3.503078] UBIFS (ubi0:0): media format: w4/r0 (latest is w4/r0), UUID 4DBB2F12-34EB-43B6-839B-3BA930765BAE, small LPT model
[    3.515582] VFS: Mounted root (ubifs filesystem) on device 0:12.
[    3.520940] Freeing unused kernel memory: 276K (c07e7000 - c082c000)
INIT: version 2.88 booting

One of the challenges I find about being fully remote is that one of the ways I think while I explain things is I draw diagrams. I m not artistic in any manner (my brothers got that skillset), but a set of boxes and lines and some text scribbled as I talk really helps. I do think even for myself, which is obviously as easy to replicate at home as in the office; I have plenty of paper and a whiteboard in my study. It s not so easy when having a design discussion with someone remotely. Doodling with a mouse doesn t quite work; my art skills are bad enough without then factoring in the fact it s not a pen-like device I m using to do it. I ve previously tried a proper graphics tablet, but there s a disconnect between where you are writing and where the output appears. That makes doing things like labelling within a diagram, or going back to draw an update, quite difficult. Or it does if you re me anyway. The modern solution is probably a laptop with a stylus capable touchscreen, but I ve shied away from such things because I don t want fingerprints all over my screen and don t want to pay extra for something I haven t previously thought I d use. An alternative is a tablet with a stylus capable screen, but those turn out to be premium models these days (remember when resistive was the cheap option because no one wanted to use the stylus?) and mine doesn t support it. You can get capacitive styli (styluses?) but then when you lean on the tablet it all gets confused. When I m due a technology refresh of my laptop or tablet I ll perhaps factor such things in, but what to do now, when I m not entirely sure how much usage I ll get out of such a device and thus can t justify a major expense on it? Buy a random thing from the internet, of course! It turns out there are a range of LCD writing tablets out there, which let you scribble on a screen and then erase it at the press of a button. An electronic etch-a-sketch, as it were. Most of them don t count as smart , with power only needed for the erase, but there appears to have been a device called the Boogie Board Sync in the past which offered some ability to save things. Searching around I found the NEWYES 10 Bluetooth Archive Writing Tablet from BangGood. Which looked like it had enough smarts to be able to send the images over bluetooth and therefore might be hackable in some manner. At 45 it seemed a reasonable punt, so I ordered one. It arrived within 2 weeks and I was surprised to find that when plugged in as a USB device it actually presented as a tablet. So much for a hackery requirement! It was detected by the kernel fine:

kernel dmesg output

usb 1-1.2: new full-speed USB device number 19 using xhci_hcd
usb 1-1.2: New USB device found, idVendor=6161, idProduct=4d15, bcdDevice=30.00
usb 1-1.2: New USB device strings: Mfr=5, Product=6, SerialNumber=0
usb 1-1.2: Product: LetSketch
usb 1-1.2: Manufacturer: LetSketch
hid-generic 0003:6161:4D15.0010: hiddev0,hidraw4: USB HID v1.11 Device [LetSketch LetSketch] on usb-0000:00:14.0-1.2/input0
input: LetSketch LetSketch as /devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1.2/1-1.2:1.1/0003:6161:4D15.0011/input/input35
hid-generic 0003:6161:4D15.0011: input,hidraw5: USB HID v1.11 Device [LetSketch LetSketch] on usb-0000:00:14.0-1.2/input1

lsusb output

Bus 001 Device 016: ID 6161:4d15  
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.00
  bDeviceClass            0 
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x6161 
  idProduct          0x4d15 
  bcdDevice           30.00
  iManufacturer           5 LetSketch
  iProduct                6 LetSketch
  iSerial                 0 
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x003b
    bNumInterfaces          2
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0xa0
      (Bus Powered)
      Remote Wakeup
    MaxPower              480mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         3 Human Interface Device
      bInterfaceSubClass      1 Boot Interface Subclass
      bInterfaceProtocol      2 Mouse
      iInterface              0 
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.11
          bCountryCode            0 Not supported
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength      18
         Report Descriptors: 
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0010  1x 16 bytes
        bInterval               2
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         3 Human Interface Device
      bInterfaceSubClass      1 Boot Interface Subclass
      bInterfaceProtocol      2 Mouse
      iInterface              0 
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.11
          bCountryCode            0 Not supported
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength      83
         Report Descriptors: 
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0010  1x 16 bytes
        bInterval               2
Device Status:     0x0003
  Self Powered
  Remote Wakeup Enabled

Nice. X wasn t happy though:

non-working Xorg log

(II) config/udev: Adding input device LetSketch LetSketch (/dev/input/event8)
(**) LetSketch LetSketch: Applying InputClass "libinput tablet catchall"
(II) Using input driver 'libinput' for 'LetSketch LetSketch'
(II) systemd-logind: got fd for /dev/input/event8 13:72 fd 34 paused 0
(**) LetSketch LetSketch: always reports core events
(**) Option "Device" "/dev/input/event8"
(**) Option "_source" "server/udev"
(II) event8  - LetSketch LetSketch: is tagged by udev as: Tablet
(EE) event8  - LetSketch LetSketch: libinput bug: missing tablet capabilities: resolution. Ignoring this device.
(II) event8  - LetSketch LetSketch: device is a tablet
(II) event8  - failed to create input device '/dev/input/event8'.
(EE) libinput: LetSketch LetSketch: Failed to create a device for /dev/input/event8
(EE) PreInit returned 2 for "LetSketch LetSketch"
(II) UnloadModule: "libinput"

I ended up digging into the libinput source to figure out what was going on here, and it turned out to be the fact there was no report of the physical size of the tablet, so no indication of what the resolution was. That s solvable with an entry in the udev hwdb for evdev devices, so I sent a patch upstream and with that applied (or just dropped into /etc/udev/hwdb.d/61-evdev-local.hwdb and then running systemd-hwdb update and replugging the device) everything looks much happier:

working Xorg log

(II) config/udev: Adding input device LetSketch LetSketch (/dev/input/event8)
(**) LetSketch LetSketch: Applying InputClass "libinput tablet catchall"
(II) Using input driver 'libinput' for 'LetSketch LetSketch'
(II) systemd-logind: got fd for /dev/input/event8 13:72 fd 86 paused 0
(**) LetSketch LetSketch: always reports core events
(**) Option "Device" "/dev/input/event8"
(**) Option "_source" "server/udev"
(II) event8  - LetSketch LetSketch: is tagged by udev as: Tablet
(II) event8  - LetSketch LetSketch: tablet 'LetSketch LetSketch' unknown to libwacom
(II) event8  - LetSketch LetSketch: device is a tablet
(II) event8  - LetSketch LetSketch: device removed
(**) Option "config_info" "udev:/sys/devices/pci0000:00/0000:00:08.1/0000:04:00.3/usb1/1-1/1-1.2/1-1.2:1.1/0003:6161:4D15.000A/input/input24/event8"
(II) XINPUT: Adding extended input device "LetSketch LetSketch" (type: TABLET, id 20)
(II) event8  - LetSketch LetSketch: is tagged by udev as: Tablet
(II) event8  - LetSketch LetSketch: tablet 'LetSketch LetSketch' unknown to libwacom
(II) event8  - LetSketch LetSketch: device is a tablet
(II) libinput: LetSketch LetSketch: needs a virtual subdevice
(**) LetSketch LetSketch Pen (0): Applying InputClass "libinput tablet catchall"
(II) Using input driver 'libinput' for 'LetSketch LetSketch Pen (0)'
(II) systemd-logind: returning pre-existing fd for /dev/input/event8 13:72
(**) LetSketch LetSketch Pen (0): always reports core events
(**) Option "Device" "/dev/input/event8"
(**) Option "_source" "_driver/libinput"
(II) libinput: LetSketch LetSketch Pen (0): is a virtual subdevice
(**) Option "config_info" "udev:/sys/devices/pci0000:00/0000:00:08.1/0000:04:00.3/usb1/1-1/1-1.2/1-1.2:1.1/0003:6161:4D15.000A/input/input24/event8"
(II) XINPUT: Adding extended input device "LetSketch LetSketch Pen (0)" (type: STYLUS, id 21)
(**) Option "AccelerationScheme" "none"
(**) LetSketch LetSketch Pen (0): (accel) selected scheme none/0
(**) LetSketch LetSketch Pen (0): (accel) acceleration factor: 2.000
(**) LetSketch LetSketch Pen (0): (accel) acceleration threshold: 4

The only additional piece I ve done is tie the tablet to a single screen, so I can then full screen whichever whiteboard system I m using on that screen and have it map to the tablet - haven t worked out how to tie it to just the application window yet, but the fullscreen approach works fine, using my smaller laptop screen. To do that I use xinput list to figure out the ID of the tablet and then xinput map-to-output 23 eDP-1 to map it to the eDP-1 output (the internal laptop screen), assuming the ID that comes out of the list is 23. But is it any good? Well, the quality of the screen isn t fantastic - no fine art or anything here - but the tablet part seems fine (complete with some pressure sensitivity) and the fact I can see what I ve drawn where I m trying to draw something new makes it a lot more useful for me. I ve had a play with just screen sharing the GIMP and doodling in that, but equally work has an O365 subscription and the Microsoft Whiteboard turns out to be pretty good without anyone I m sharing with needing to install anything. Of course my artistic skills are still dreadful, but I have actually managed to use it for drawing out a couple of things while discussing them, so I m considering that a win. Saved Tablet image

As a reader of Planet Debian I see a bunch of updates at the start of each month about what people are up to in terms of their Free Software activities. I m not generally active enough in the Free Software world to justify a monthly report, but I did a report of my Free Software Activities for 2019 and thought I d do another for 2020. I ended up not doing as much as last year; I put a lot of that down to fatigue about the state of the world and generally not wanting to spend time on the computer at the end of the working day.

Conferences 2020 was unsurprisingly not a great year for conference attendance. I was fortunate enough to make it to FOSDEM and CopyleftConf 2020 - I didn t speak at either, but had plenty of interesting hallway track conversations as well as seeing some good talks. I hadn t been planning to attend DebConf20 due to time constraints, but its move to an entirely online conference meant I was able to attend a few talks at least. I have to say I don t like virtual conferences as much as the real thing; it s not as easy to have the casual chats at them, and it s also harder to carve out the exclusive time when you re at home. That said I spoke at NIDevConf this year, which was also fully virtual. It s not a Free Software focussed conference, but there s a lot of crossover in terms of technologies and I spoke on my experiences with Go, some of which are influenced by my packaging experiences within Debian.

Debian Most of my contributions to Free software happen within Debian. As part of the Data Protection Team I responded to various inbound queries to that team. Some of this involved chasing up other project teams who had been slow to respond - folks, if you re running a service that stores personal data about people then you need to be responsive to requests about it. The Debian Keyring was possibly my largest single point of contribution. We re in a roughly 3 month rotation of who handles the keyring updates, and I handled 2020.02.02, 2020.03.24, 2020.06.24, 2020.09.24 + 2020.12.24 For Debian New Members I m mostly inactive as an application manager - we generally seem to have enough available recently. If that changes I ll look at stepping in to help, but I don t see that happening. I continue to be involved in Front Desk, having various conversations throughout the year with the rest of the team, but there s no doubt Mattia and Pierre-Elliott are the real doers at present. In terms of package uploads I continued to work on gcc-xtensa-lx106, largely doing uploads to deal with updates to the GCC version or packaging (5, 6 + 7). sigrok had a few minor updates, libsigkrok 0.5.2-2, libsigrokdecode 0.5.3-2 as well as a new upstream release of Pulseview 0.4.2-1 and a fix to cope with change to QT 0.4.2-2. Due to the sigrok-firmware requirement on sdcc I also continued to help out there, updating to 4.0.0+dfsg-1 and doing some fixups in 4.0.0+dfsg-2. Despite still not writing an VHDL these days I continue to try and make sure ghdl is ok, because I found it a useful tool in the past. In 2020 that meant a new upstream release, 0.37+dfsg-1 along with a couple of more minor updates (0.37+dfsg-2 + 0.37+dfsg-3. libcli had a new upstream release, 1.10.4-1, and I did a long overdue update to sendip to the latest upstream release, 2.6-1 having been poked about an outstanding bug by the Reproducible Builds folk. OpenOCD is coming up to 4 years since its last stable release, but I did a snapshot upload to Debian experimental (0.10.0+g20200530-1) and a subsequent one to unstable (0.10.0+g20200819-1). There are also moves to produce a 0.11.0 release and I uploaded 0.11.0~rc1-1 as a result. libjaylink got a bump as a result (0.2.0-1) after some discussion with upstream.

OpenOCD On the subject of OpenOCD I ve tried to be a bit more involved upstream. I m not familiar enough with the intricacies of JTAG/SWD/the various architectures supported to contribute to the core, but I pushed the config for my HIE JTAG adapter upstream and try and review patches that don t require in depth hardware knowledge.

Linux I ve been contributing to the Linux kernel for a number of years now, mostly just minor bits here and there for issues I hit. This year I spent a lot of time getting support for the MikoTik RB3011 router upstreamed. That included the basic DTS addition, fixing up QCA8K to support SGMII CPU connections, adding proper 802.1q VLAN support to QCA8K and cleaning up an existing QCOM ADM driver that s required for the NAND. There were a number of associated bugfixes/minor changes found along the way too. It can be a little frustrating at times going round the review loop with submitting things upstream, but I do find it quite satisfying when it all comes together and I have no interest in weird vendor trees that just bitrot over time.

Software in the Public Interest I haven t sat on the board of SPI since 2015 but I was still acting as the primary maintainer of the membership website (with Martin Michlmayr as the other active contributor) and hosting it on my own machine. I managed to finally extricate myself from this role in August. I remain a contributing member.

Personal projects 2020 finally saw another release (0.6.0, followed swiftly by 0.6.1 to allow the upload of 0.6.1-1 to Debian) of onak. This release finally adds various improvements to deal with the hostility shown to the OpenPGP keyserver network in recent years, including full signature verification as an option. I fixed an oversight in my Digoo/1-wire temperature decoder and a bug that turned up on ARM but not MIPS in my mqtt-arp code. I should probably package it for Debian (even if I don t upload it), as I m running it on my RB3011 now.

I have an original Tesco Hudl - a Rockchip RK3188 based Android tablet. It s somewhat long in the tooth and mine is running Android 4.2.2 (Jelly Bean). As a first step in trying to get it updated a bit I decided to root it and have a poke about. There are plenty of guides for this, but they mostly involve downloading Android apps that look dodgy or don t exist any more. Thankfully the bootloader is unlocked, so I did it the hard (manual) way from a Debian 10 (Buster) box. I doubt this is useful to many folk, but I thought I d write it up. As you d expect follow this at your own risk; there is the potential to brick the Hudl. First, enable developer mode on the Hudl (so we can adb in). Open the Settings app, scroll down to the bottom and click About Tablet , scroll down to the bottom and tap Build number 7 times, at which point it will tell you You are now a developer! . Go back to the main settings menu and just above About Tablet there will now be a Developer options entry. Click it, then make sure the box beside USB debugging is ticked. Now you need to install the appropriate tools on your Debian box. That should be:

$ sudo apt install adb rkflashtool

We also need to download a suitable su tool. I lazily went for the prebuilt SuperSU Root:

$ mkdir hudl-root
$ cd hudl-root
$ wget https://supersuroot.org/downloads/SuperSU-v2.79-201612051815.zip
$ unzip SuperSU-v2.79-201612051815.zip

2.82 is the latest version but has problems on Jelly Bean; the device will end up not properly booting. Hook the Hudl up to your machine with a suitable USB cable and you ll now be able to get a shell on it:

$ adb shell
* daemon not running; starting now at tcp:5037
* daemon started successfully
shell@android:/ $

Ctrl-D will quit the shell and return you back to the local prompt. Next step is to reboot into the Rockchip bootloader, and use that to download the system partition (just over 1G in size)

$ adb reboot bootloader
$ sudo rkflashtool r system > system.img
rkflashtool: info: rkflashtool v5.2
rkflashtool: info: Detected RK3188...
rkflashtool: info: interface claimed
rkflashtool: info: working with partition: system
rkflashtool: info: found offset: 0x00142000
rkflashtool: info: found size: 0x00200000
rkflashtool: info: reading flash memory at offset 0x00341fe0... Done!

We now have a system.img file which represents the system partition of the device. We can mount that and copy over the su binary and SuperSU apk.

$ sudo mount -o loop system.img /mnt
$ sudo cp common/Superuser.apk /mnt/app/
$ sudo cp armv7/su /mnt/xbin/
$ sudo chmod +sx /mnt/xbin/su
$ sudo umount /mnt

Finally we can write this image back to the device, reboot and once the reboot has completed use adb to connect and su to root. SuperSU might pop up a dialog on the tablet asking you to ok the action (and possibly indicate it needs to do a fixup of the installation):

$ sudo rkflashtool w system < system.img
$ sudo rkflashtool b
$ adb shell
shell@android:/ $ su -
root@android:/ #

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