Search Results: "mt"

8 December 2023

Jonathan Dowland: The scourge of Electron, the nostalgia of Pidgin

For reasons I won't go into right now, I've spent some of this year working on a refurbished Lenovo Thinkpad Yoga 260. Despite it being relatively underpowered, I love almost everything about it. Unfortunately the model I bought has 8G RAM which turned out to be more limiting than I thought it would be. You can do incredible things with 8G of RAM: incredible, wondrous things. And most of my work, whether that's wrangling containers, hacking on OpenJDK, or complex Haskell projects, are manageable. Where it falls down is driving the modern scourge: Electron, and by proxy, lots of modern IM tools: Slack (urgh), Discord (where one of my main IRC social communities moved to), WhatsApp Web1 and even Signal Desktop. For that reason, I've (temporarily) looked at alternatives, and I was pleasantly surprised to find serviceable plugins for Pidgin, the stalwart Instant Messenger multiplexer. I originally used Pidgin (then called Gaim) back in the last century, at the time to talk to ICQ, MSN Messenger and AIM (all but ICQ2 long dead). It truly is an elegant weapon from a more civilized age.
Discord from within Pidgin Discord from within Pidgin
The plugins are3: Pidgin with all of these plugins loaded runs perfectly well and consumes fractions of the RAM that each of those Electron apps did prior. A side-effect of moving these into Pidgin (in particular Discord) is a refocussing of the content. Fewer distractions around the text. The lack of auto-link embedding, and other such things, make it a cleaner, purer experience. This made me think of the Discord community I am in (I'm really only active in one). It used to be an IRC channel of people that I met through a mutual friend. Said friend recently departed Discord, due to the signal to noise ratio being too poor, and the incessant nudge to click on links, engage, engage, engage. I wonder if the experience mediated by Pidgin would be more tolerable to them?
What my hexchat looks like What my hexchat looks like
I'm still active in one IRC channel (and inactive in many more). I could consider moving IRC into Pidgin as well. At the moment, my IRC client of choice is hexchat, which (like Pidgin) is still using GTK2 for the UI. There's something perversely pleasant about that.

  1. if you go to the trouble of trying to run it as an application distinct from your web browser.
  2. I'm still somewhat surprised ICQ is still going. I might try and recover my old ID.
  3. There may or may not be similar plugins for Slack, but as I (am forced to) use that for corporate stuff, I'm steering clear of them.

7 December 2023

Daniel Kahn Gillmor: New OpenPGP certificate for dkg, December 2023

dkg's New OpenPGP certificate in December 2023 In December of 2023, I'm moving to a new OpenPGP certificate. You might know my old OpenPGP certificate, which had an fingerprint of C29F8A0C01F35E34D816AA5CE092EB3A5CA10DBA. My new OpenPGP certificate has a fingerprint of: D477040C70C2156A5C298549BB7E9101495E6BF7. Both certificates have the same set of User IDs:
  • Daniel Kahn Gillmor
  • <dkg@debian.org>
  • <dkg@fifthhorseman.net>
You can find a version of this transition statement signed by both the old and new certificates at: https://dkg.fifthhorseman.net/2023-dkg-openpgp-transition.txt The new OpenPGP certificate is:
-----BEGIN PGP PUBLIC KEY BLOCK-----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=9Yc8
-----END PGP PUBLIC KEY BLOCK-----
When I have some reasonable number of certifications, i'll update the certificate associated with my e-mail addresses on https://keys.openpgp.org, in DANE, and in WKD. Until then, those lookups should continue to provide the old certificate.

3 December 2023

Ben Hutchings: FOSS activity in November 2023

Dirk Eddelbuettel: dang 0.0.16: New Features, Some Maintenance

A new release of my mixed collection of things package dang package arrived at CRAN a little while ago. The dang package regroups a few functions of mine that had no other home as for example lsos() from a StackOverflow question from 2009 (!!), the overbought/oversold price band plotter from an older blog post, the market monitor blogged about as well as the checkCRANStatus() function tweeted about by Tim Taylor. And more so take a look. This release brings a number of updates, including a rather nice improvement to the market monitor making updates buttery smooth and not flickering (with big thanks to Paul Murrell who calmly pointed out once again that base R does of course have the functionality I was seeking) as well as three new functions (!!) and then a little maintenance on the -Wformat print format string issue that kept everybody busy this week. The NEWS entry follows.

Changes in version 0.0.16 (2023-12-02)
  • Added new function str.language() based on post by Bill Dunlap
  • Added new argument sleep in intradayMarketMonitor
  • Switched to dev.hold() and dev.flush() in intradayMarketMonitor with thanks to Paul Murrell
  • Updated continued integration setup, twice, and package badges
  • Added new function shadowedPackages
  • Added new function limitDataTableCores
  • Updated two error() calls to updated tidyCpp signature to not tickle -Wformat warnings under R-devel
  • Updated two URL to please link checks in R-devel
  • Switch two tests for variable of variable to is.* and inherits(), respectively

Courtesy of my CRANberries, there is a comparison to [the previous release][previous releases]. For questions or comments use the the issue tracker at the GitHub repo. If you like this or other open-source work I do, you can now sponsor me at GitHub.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

30 November 2023

Dirk Eddelbuettel: RcppSpdlog 0.0.15 on CRAN: Maintenance

Version 0.0.15 of RcppSpdlog is now on CRAN and will be uploaded to Debian. RcppSpdlog bundles spdlog, a wonderful header-only C++ logging library with all the bells and whistles you would want that was written by Gabi Melman, and also includes fmt by Victor Zverovich. You can learn more at the nice package documention site. This releases updates the code to address warning now shown under R-devel when -Wformat -Wformat-security are enabled. This amounted to re-generating RcppExports.cpp under an updated [Rcpp][rcpp] version. It also updates the package default help page by removing some stubs that were not filled in. The NEWS entry for this release follows.

Changes in RcppSpdlog version 0.0.15 (2023-11-29)
  • Correct default package help page slighly
  • RcppExports.cpp has been regenerated under an updated Rcpp to address a format string warning under R-devel

Courtesy of my CRANberries, there is also a diffstat report. More detailed information is on the RcppSpdlog page, or the package documention site. If you like this or other open-source work I do, you can sponsor me at GitHub.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

29 November 2023

Jonathan Dowland: Useful vim plugins: AnsiEsc

Sometimes I have to pore over long debugging logs which have originally been written out to a terminal and marked up with colour or formatting via ANSI escape codes. The formatting definitely makes reading them easier, but I want to read them in Vim, rather than a terminal, and (out of the box) Vim doesn't render the formatting. Cue AnsiEsc.vim: an OG Vim script1 that translates some ANSI escape codes in particular some colour specifying ones into Vim syntax highlighting. This makes viewing and navigating around multi-MiB console log files much nicer.

  1. AnsiEsc is old enough to have been distributed as a script, and then as a "vimball", an invention of the same author to make installing Vim scripts easier. It pre-dates the current fashion for plugins, but someone else has updated it and repackaged it as a plugin. I haven't tried that out.

24 November 2023

Jonathan Dowland: Dockerfile ARG footgun

This week I stumbled across a footgun in the Dockerfile/Containerfile ARG instruction. ARG is used to define a build-time variable, possibly with a default value embedded in the Dockerfile, which can be overridden at build-time (by passing --build-arg). The value of a variable FOO is interpolated into any following instructions that include the token $FOO. This behaves a little similar to the existing instruction ENV, which, for RUN instructions at least, can also be interpolated, but can't (I don't think) be set at build time, and bleeds through to the resulting image metadata. ENV has been around longer, and the documentation indicates that, when both are present, ENV takes precedence. This fits with my mental model of how things should work, but, what the documentation does not make clear is, the ENV doesn't need to have been defined in the same Dockerfile: environment variables inherited from the base image also override ARGs. To me this is unexpected and far less sensible: in effect, if you are building a layered image and want to use ARG, you have to be fairly sure that your base image doesn't define an ENV of the same name, either now or in the future, unless you're happy for their value to take precedence. In our case, we broke a downstream build process by defining a new environment variable USER in our image. To defend against the unexpected, I'd recommend using somewhat unique ARG names: perhaps prefix something unusual and unlikely to be shadowed. Or don't use ARG at all, and push that kind of logic up the stack to a Dockerfile pre-processor like CeKit.

Jonathan Dowland: bndcmpr

Last year I put together a Halloween playlist and tried, where possible, to link to the tracks on Bandcamp. At the time, Bandcamp did not offer a Playlist feature; they've since added one, but it's limited to mobile only (and I've found, not a lot of use there either). (I also provided a Spotify playlist. Not all of the tracks in the playlist were available on Spotify, or Bandcamp.) Since then I discovered an independent service bndcmpr which lets you build and share playlists from tracks hosted on Bandcamp. I'm not sure whether it will have longevity, but for now at least, I've ported my Halloween 2022 playlist over to bndcmpr. You can find it here: https://bndcmpr.co/cae6814a, or with any luck, embedded below (if you are reading this post on an aggregation site, or newsreader, it's less likely that this will appear):
I'm overdue cutting the next playlist, theme TBA. Stay tuned.

17 November 2023

Jonathan Dowland: HLedger, regex matches and field assignments

I've finally landed a patch/feature for HLedger I've been working on-and-off (mostly off) since around March. HLedger has a powerful CSV importer which you configure with a set of rules. Rules consist of conditional matchers (does field X in this CSV row match this regular expression?) and field assignments (set the resulting transaction's account to Y). motivating problem 1 Here's an example of one of my rules for handling credit card repayments. This rule is applied when I import a CSV for my current account, which pays the credit card:
if AMERICAN EXPRESS
    account2 liabilities:amex
This results in a ledger entry like the following
2023-10-31 AMERICAN EXPRESS
    assets:current           - 6.66
    liabilities:amex           6.66
My current account statements cover calendar months. My credit card period spans mid-month to mid-month. I pay it off by direct debit, which comes out after the credit card period, towards the very end of the calendar month. That transaction falls roughly halfway through the next credit card period. On my credit card statements, that repayment is "warped" to the start of the list of transactions, clearing the outstanding balance from the previous period. When I import my credit card data to HLedger, I want to compare the result against a PDF statement to make sure my ledger matches reality. The repayment "warping" makes this awkward, because it means the balance for roughly half the new transactions (those that fall before the real-date of the repayment) don't match up. motivating problem 2 I start new ledger files each year. I need to import the closing balances from the previous year to the next, which I do by exporting the final balance from the previous year in CSV and importing that into the new ledgers in the usual way. Between 2022 and 2023 I changed the scheme I use for account names so I need to translate between the old and the new in the opening balances. I couldn't think of a way of achieving this in the import rules (besides writing a bespoke rule for every possible old account name) so I abused another HLedger feature instead, HLedger aliases. For example I added this alias in my family ledger file for 2023
alias /^family:(.*)/ = \1
These are ugly and I'd prefer to get rid of them. regex match groups A common feature of regular expressions is defining match groups which can be referenced elsewhere, such as on the far-side of a substitution. I added match group support to HLedger's field assignments. addressing date warping Here's an updated version rule from the first motivating problem:
if AMERICAN EXPRESS
& %date (..)/(..)/(....)
    account2 liabilities:amex
    comment2 date:\3-\2-16
We now match on on extra date field, and surround the day/month/year components with parentheses to define match groups. We add a second field assignment too, setting the second posting's "comment" field to a string which, once the match groups are interpolated, instructs HLedger to do date warping (I wrote about this in date warping in HLedger) The new transaction looks like this:
2023-10-31 AMERICAN EXPRESS
    assets:current           - 6.66
    liabilities:amex           6.66 ; date:2023-10-16
getting rid of aliases In the second problem, I can strip off the unwanted account name prefixes at CSV import time, with rules like this
if %account2 ^family:(.*)$
    account2 \1
When! This stuff landed a week ago in early November, and is not yet in a Hledger release.

Jonathan Dowland: denver luna

picture of the denver luna record on a turntable
I haven't done one of these in a while! Denver Luna is the latest single from Underworld, here on a pink 12" vinyl. The notable thing about this release was it was preceded by an "acapella" mix, consisting of just Karl Hyde's vocals: albeit treated and layered. Personally I prefer the "main" single mix, which calls back to their biggest hits. The vinyl also features an instrumental take, which is currently unavailable in any other formats. The previous single (presumably both from a forthcoming album) was and the colour red. In this crazy world we live in, this was limited to 1,000 copies. Flippers have sold 4 on eBay already, at between 55 and 75.

12 November 2023

Lukas M rdian: Netplan brings consistent network configuration across Desktop, Server, Cloud and IoT

Ubuntu 23.10 Mantic Minotaur Desktop, showing network settings We released Ubuntu 23.10 Mantic Minotaur on 12 October 2023, shipping its proven and trusted network stack based on Netplan. Netplan is the default tool to configure Linux networking on Ubuntu since 2016. In the past, it was primarily used to control the Server and Cloud variants of Ubuntu, while on Desktop systems it would hand over control to NetworkManager. In Ubuntu 23.10 this disparity in how to control the network stack on different Ubuntu platforms was closed by integrating NetworkManager with the underlying Netplan stack. Netplan could already be used to describe network connections on Desktop systems managed by NetworkManager. But network connections created or modified through NetworkManager would not be known to Netplan, so it was a one-way street. Activating the bidirectional NetworkManager-Netplan integration allows for any configuration change made through NetworkManager to be propagated back into Netplan. Changes made in Netplan itself will still be visible in NetworkManager, as before. This way, Netplan can be considered the single source of truth for network configuration across all variants of Ubuntu, with the network configuration stored in /etc/netplan/, using Netplan s common and declarative YAML format.

Netplan Desktop integration On workstations, the most common scenario is for users to configure networking through NetworkManager s graphical interface, instead of driving it through Netplan s declarative YAML files. Netplan ships a libnetplan library that provides an API to access Netplan s parser and validation internals, which is now used by NetworkManager to store any network interface configuration changes in Netplan. For instance, network configuration defined through NetworkManager s graphical UI or D-Bus API will be exported to Netplan s native YAML format in the common location at /etc/netplan/. This way, the only thing administrators need to care about when managing a fleet of Desktop installations is Netplan. Furthermore, programmatic access to all network configuration is now easily accessible to other system components integrating with Netplan, such as snapd. This solution has already been used in more confined environments, such as Ubuntu Core and is now enabled by default on Ubuntu 23.10 Desktop.

Migration of existing connection profiles On installation of the NetworkManager package (network-manager >= 1.44.2-1ubuntu1) in Ubuntu 23.10, all your existing connection profiles from /etc/NetworkManager/system-connections/ will automatically and transparently be migrated to Netplan s declarative YAML format and stored in its common configuration directory /etc/netplan/. The same migration will happen in the background whenever you add or modify any connection profile through the NetworkManager user interface, integrated with GNOME Shell. From this point on, Netplan will be aware of your entire network configuration and you can query it using its CLI tools, such as sudo netplan get or sudo netplan status without interrupting traditional NetworkManager workflows (UI, nmcli, nmtui, D-Bus APIs). You can observe this migration on the apt-get command line, watching out for logs like the following:
Setting up network-manager (1.44.2-1ubuntu1.1) ...
Migrating HomeNet (9d087126-ae71-4992-9e0a-18c5ea92a4ed) to /etc/netplan
Migrating eduroam (37d643bb-d81d-4186-9402-7b47632c59b1) to /etc/netplan
Migrating DebConf (f862be9c-fb06-4c0f-862f-c8e210ca4941) to /etc/netplan
In order to prepare for a smooth transition, NetworkManager tests were integrated into Netplan s continuous integration pipeline at the upstream GitHub repository. Furthermore, we implemented a passthrough method of handling unknown or new settings that cannot yet be fully covered by Netplan, making Netplan future-proof for any upcoming NetworkManager release.

The future of Netplan Netplan has established itself as the proven network stack across all variants of Ubuntu Desktop, Server, Cloud, or Embedded. It has been the default stack across many Ubuntu LTS releases, serving millions of users over the years. With the bidirectional integration between NetworkManager and Netplan the final piece of the puzzle is implemented to consider Netplan the single source of truth for network configuration on Ubuntu. With Debian choosing Netplan to be the default network stack for their cloud images, it is also gaining traction outside the Ubuntu ecosystem and growing into the wider open source community. Within the development cycle for Ubuntu 24.04 LTS, we will polish the Netplan codebase to be ready for a 1.0 release, coming with certain guarantees on API and ABI stability, so that other distributions and 3rd party integrations can rely on Netplan s interfaces. First steps into that direction have already been taken, as the Netplan team reached out to the Debian community at DebConf 2023 in Kochi/India to evaluate possible synergies.

Conclusion Netplan can be used transparently to control a workstation s network configuration and plays hand-in-hand with many desktop environments through its tight integration with NetworkManager. It allows for easy network monitoring, using common graphical interfaces and provides a single source of truth to network administrators, allowing for configuration of Ubuntu Desktop fleets in a streamlined and declarative way. You can try this new functionality hands-on by following the Access Desktop NetworkManager settings through Netplan tutorial.
If you want to learn more, feel free to follow our activities on Netplan.io, GitHub, Launchpad, IRC or our Netplan Developer Diaries blog on discourse.

10 November 2023

Jonathan Dowland: Plato document reader

Kobo Libra 2 Kobo Libra 2
text-handling in Plato text-handling in Plato
Until now, I haven't hacked my Kobo Libra 2 ereader, despite knowing it is a relatively open device. The default document reader (Nickel) does everything I need it to. Syncing the books via USB is tedious, but I don't do it that often. Via Videah's blog post My E-Reader Setup, I learned of Plato, an alternative document reader. Plato doesn't really offer any headline features that I need, but it cost me nothing to try it out, so I installed it (fairly painlessly) and launched it just once. The library view seems good, although I've not used it much: I picked a book and read it through1, and I'm 60% through another2. I tend to read one ebook at a time. The main reader interface is great: Just the text3. Page transitions are really, really fast. Tweaking the backlight intensity is a little slower than Nickel: menu-driven rather than an active scroll region (which is convenient in Nickel but easy to accidentally turn to 0% and hard to recover from in pitch black). Now that I've started down the road of hacking the Kobo, I think I will explore wifi-syncing the library, perhaps using a variation on the hook scripts shared in Videah's blog post.

  1. Venomous Lumpsucker by Ned Beauman. It's fantastic. Guardian review
  2. There Is No Antimemetics Division by qntm
  3. I do miss Nickel's tiny progress bar somewhat: the only non-text bit of UX I left turned on.

7 November 2023

Jonathan Dowland: gitsigns (useful neovim plugins)

gitsigns is a Neovim plugin which adds a wonderfully subtle colour annotation in the left-hand gutter to reflect changes in the buffer since the last git commit1. My long-term habit with Vim and Git is to frequently background Vim (^Z) to invoke the git command directly and then foreground Vim again (fg). Over the last few years I've been trying more and more to call vim-fugitive from within Vim instead. (I still do rebases and most merges the old-fashioned way). For the most part Gitsigns is a nice passive addition to that, but it can also do a lot of useful things that Fugitive also does. Previewing changed hunks in a little floating window, in particular when resolving an awkward merge conflict, is very handy.
An example screenshot of the Gitsigns plugin
The above picture shows it in action. I've changed two lines and added another three in the top-left buffer. Gitsigns tries to choose colours from the currently active colour scheme (in this case, tender)

  1. by default Gitsigns shows changes since the last commit, as git diff does, but you can easily switch out the base from which it compares.

26 October 2023

Dima Kogan: Talking to ROS from outside a LAN

The problem
This is about ROS version 1. Version 2 is different, and maybe they fixed stuff. But I kinda doubt it since this thing is heinous in a million ways. Alright so let's say we have have some machines in a LAN doing ROS stuff and we have another machine outside the LAN that wants to listen in (like to get a realtime visualization, say). This is an extremely common scenario, but they created enough hoops to make this not work. Let's say we have 3 computers:
  • router: the bridge between the two networks. This has two NICs. The inner IP is 10.0.1.1 and the outer IP is 12.34.56.78
  • inner: a machine in the LAN that's doing ROS stuff. IP 10.0.1.99
  • outer: a machine outside that LAN that wants to listen in. IP 12.34.56.99
Let's say the router is doing ROS stuff. It's running the ROS master and some nodes like this:
ROS_IP=10.0.1.1 roslaunch whatever
If you omit the ROS_IP it'll pick router, which may or may not work, depending on how the DNS is set up. Here we set it to 10.0.1.1 to make it possible for the inner machine to communicate (we'll see why in a bit). An aside: ROS should use the IP by default instead of the name because the IP will work even if the DNS isn't set up. If there are multiple extant IPs, it should throw an error. But all that would be way too user-friendly. OK. So we have a ROS master on 10.0.1.1 on the default port: 11311. The inner machine can rostopic echo and all that. Great. What if I try to listen in from outer? I say
ROS_MASTER_URI=http://12.34.56.78:11311 rostopic list
This connects to the router on that port, and it works well: I get the list of available topics. Here this works because the router is the router. If inner was running the ROS master then we'd need to do a forward for port 11311. In any case, this works and we understand it. So clearly we can talk to the ROS master. Right? Wrong! Let's actually listen in on a specific topic on outer:
ROS_MASTER_URI=http://12.34.56.78:11311 rostopic echo /some/topic
This does not work. No errors are reported. It just sits there, which looks like no data is coming in on that topic. But this is a lie: it's actually broken.

The diagnosis
So this is our problem. It's a very common use case, and there are plenty of internet people asking about it, with no specific solutions. I debugged it, and the details are here. To figure out what's going on, I made a syscall log on a machine inside the LAN, where a simple rostopic echo does work:
sysdig -A proc.name=rostopic and fd.type contains ipv -s 2000
This shows us all the communication between inner running rostopic and the server. It's really chatty. It's all TCP. There are multiple connections to the router on port 11311. It also starts up multiple TCP servers on the client that listen to connections; these are likely to be broken if we were running the client on outer and a machine inside the LAN tried to talk to them; but thankfully in my limited testing nothing actually tried to talk to them. The conversations on port 11311 are really long, but here's the punchline. inner tells the router:
POST /RPC2 HTTP/1.1                                                                                                                 
Host: 10.0.1.1:11311                                                                                                          
Accept-Encoding: gzip                                                                                                               
Content-Type: text/xml                                                                                                              
User-Agent: Python-xmlrpc/3.11                                                                                                      
Content-Length: 390                                                                                                                 
<?xml version='1.0'?>
<methodCall>
<methodName>registerSubscriber</methodName>
<params>
<param>
<value><string>/rostopic_2447878_1698362157834</string></value>
</param>
<param>
<value><string>/some/topic</string></value>
</param>
<param>
<value><string>*</string></value>
</param>
<param>
<value><string>http://inner:38229/</string></value>
</param>
</params>
</methodCall>
Yes. It's laughably chatty. Then the router replies:
HTTP/1.1 200 OK
Server: BaseHTTP/0.6 Python/3.8.10
Date: Thu, 26 Oct 2023 23:15:28 GMT
Content-type: text/xml
Content-length: 342
<?xml version='1.0'?>
<methodResponse>
<params>
<param>
<value><array><data>
<value><int>1</int></value>
<value><string>Subscribed to [/some/topic]</string></value>
<value><array><data>
<value><string>http://10.0.1.1:45517/</string></value>
</data></array></value>
</data></array></value>
</param>
</params>
</methodResponse>
Then this sequence of system calls happens in the rostopic process (an excerpt from the sysdig log):
> connect fd=10(<4>) addr=10.0.1.1:45517
< connect res=-115(EINPROGRESS) tuple=10.0.1.99:47428->10.0.1.1:45517 fd=10(<4t>10.0.1.99:47428->10.0.1.1:45517)
< getsockopt res=0 fd=10(<4t>10.0.1.99:47428->10.0.1.1:45517) level=1(SOL_SOCKET) optname=4(SO_ERROR) val=0 optlen=4
So the inner client makes an outgoing TCP connection on the address given to it by the ROS master above: 10.0.1.1:45517. This IP is only accessible from within the LAN, which works fine when talking to it from inner, but would be a problem from the outside. Furthermore, some sort of single-port-forwarding scheme wouldn't fix connecting from outer either, since the port number is dynamic. To confirm what we think is happening, the sequence of syscalls when trying to rostopic echo from outer does indeed fail:
connect fd=10(<4>) addr=10.0.1.1:45517 
connect res=-115(EINPROGRESS) tuple=10.0.1.1:46204->10.0.1.1:45517 fd=10(<4t>10.0.1.1:46204->10.0.1.1:45517)
getsockopt res=0 fd=10(<4t>10.0.1.1:46204->10.0.1.1:45517) level=1(SOL_SOCKET) optname=4(SO_ERROR) val=-111(ECONNREFUSED) optlen=4
That's the breakage mechanism: the ROS master asks us to communicate on an address we can't talk to. Debugging this is easy with sysdig:
sudo sysdig -A -s 400 evt.buffer contains '"Subscribed to"' and proc.name=rostopic
This prints out all syscalls seen by the rostopic command that contain the string Subscribed to, so you can see that different addresses the ROS master gives us in response to different commands. OK. So can we get the ROS master to give us an address that we can actually talk to? Sorta. Remember that we invoked the master with
ROS_IP=10.0.1.1 roslaunch whatever
The ROS_IP environment variable is exactly the address that the master gives out. So in this case, we can fix it by doing this instead:
ROS_IP=12.34.56.78 roslaunch whatever
Then the outer machine will be asked to talk to 12.34.56.78:45517, which works. Unfortunately, if we do that, then the inner machine won't be able to communicate. So some sort of ssh port forward cannot fix this: we need a lower-level tunnel, like a VPN or something. And another rant. Here rostopic tried to connect to an unreachable address, which failed. But rostopic knows the connection failed! It should throw an error message to the user. Something like this would be wonderful:
ERROR! Tried to connect to 10.0.1.1:45517 ($ROS_IP:dynamicport), but connect() returned ECONNREFUSED
That would be immensely helpful. It would tell the user that something went wrong (instead of no data being sent), and it would give a strong indication of the problem and how to fix it. But that would be asking too much.

The solution
So we need a VPN-like thing. I just tried sshuttle, and it just works. Start the ROS node in the way that makes connections from within the LAN work:
ROS_IP=10.0.1.1 roslaunch whatever
Then on the outer client:
sshuttle -r router 10.0.1.0/24
This connects to the router over ssh and does some hackery to make all connections from outer to 10.0.1.x transparently route into the LAN. On all ports. rostopic echo then works. I haven't done any thorough testing, but hopefully it's reliable and has low overhead; I don't know. I haven't tried it but almost certainly this would work even with the ROS master running on inner. This would be accomplished like this:
  1. Tell ssh how to connect to inner. Dropping this into ~/.ssh/config should do it:
    Host inner
    HostName 10.0.1.99
    ProxyJump router
    
  2. Do the magic thing:
    sshuttle -r inner 10.0.1.0/24
    
I'm sure any other VPN-like thing would work also.

23 October 2023

Jonathan Dowland: cherished

minidisc player
iPod
Bose headphones
If I think back to technology I've used and really cherished, quite often they're audio-related: Minidisc players, Walkmans, MP3 players, headphones. These pieces of technology served as vessels to access music, which of course I often have fond emotional connection to. And so I think the tech has benefited from that, and in some way the fondness or emotional connection to music has somewhat transferred or rubbed-off on the technology to access it. Put another way, no matter how well engineered it was, how easy it was to use or how well it did the job, I doubt I'd have fond memories, years later, of a toilet brush. I wonder if the same "bleeding" of fondness applies to brands, too. If so, and if you were a large tech company, it would be worth having some audio gear in your portfolio. I think Sony must have benefited from this. Apple too. on-ear phones For listening on-the-go, I really like on-ear headphones, as opposed to over-ear. I have some lovely over-ear phones for listening-at-rest, but they get my head too hot when I'm active. The on-ears are a nice compromise between comfort and quality of over-ear, and portability of in-ear. Most of the ones I've owned have folded up nicely into a coat pocket too. My current Bose pair are from 2019 and might be towards the end of their life. They replaced some AKG K451s, which were also discontinued. Last time I looked (2019) the Sony offerings in this product category were not great. That might have changed. But I fear that the manufacturers have collectively decided this product category isn't worth investing in.

12 October 2023

Reproducible Builds: Reproducible Builds in September 2023

Welcome to the September 2023 report from the Reproducible Builds project In these reports, we outline the most important things that we have been up to over the past month. As a quick recap, whilst anyone may inspect the source code of free software for malicious flaws, almost all software is distributed to end users as pre-compiled binaries.
Andreas Herrmann gave a talk at All Systems Go 2023 titled Fast, correct, reproducible builds with Nix and Bazel . Quoting from the talk description:

You will be introduced to Google s open source build system Bazel, and will learn how it provides fast builds, how correctness and reproducibility is relevant, and how Bazel tries to ensure correctness. But, we will also see where Bazel falls short in ensuring correctness and reproducibility. You will [also] learn about the purely functional package manager Nix and how it approaches correctness and build isolation. And we will see where Bazel has an advantage over Nix when it comes to providing fast feedback during development.
Andreas also shows how you can get the best of both worlds and combine Nix and Bazel, too. A video of the talk is available.
diffoscope is our in-depth and content-aware diff utility that can locate and diagnose reproducibility issues. This month, Chris Lamb fixed compatibility with file(1) version 5.45 [ ] and updated some documentation [ ]. In addition, Vagrant Cascadian extended support for GNU Guix [ ][ ] and updated the version in that distribution as well. [ ].
Yet another reminder that our upcoming Reproducible Builds Summit is set to take place from October 31st November 2nd 2023 in Hamburg, Germany. If you haven t been before, our summits are a unique gathering that brings together attendees from diverse projects, united by a shared vision of advancing the Reproducible Builds effort. During this enriching event, participants will have the opportunity to engage in discussions, establish connections and exchange ideas to drive progress in this vital field. If you re interested in joining us this year, please make sure to read the event page, the news item, or the invitation email that Mattia Rizzolo sent out recently, all of which have more details about the event and location. We are also still looking for sponsors to support the event, so please reach out to the organising team if you are able to help. Also note that PackagingCon 2023 is taking place in Berlin just before our summit.
On the Reproducible Builds website, Greg Chabala updated the JVM-related documentation to update a link to the BUILDSPEC.md file. [ ] And Fay Stegerman fixed the builds failing because of a YAML syntax error.

Distribution work In Debian, this month: September saw F-Droid add ten new reproducible apps, and one existing app switched to reproducible builds. In addition, two reproducible apps were archived and one was disabled for a current total of 199 apps published with Reproducible Builds and using the upstream developer s signature. [ ] In addition, an extensive blog post was posted on f-droid.org titled Reproducible builds, signing keys, and binary repos .

Upstream patches The Reproducible Builds project detects, dissects and attempts to fix as many currently-unreproducible packages as possible. We endeavour to send all of our patches upstream where appropriate. This month, we wrote a large number of such patches, including:

Testing framework The Reproducible Builds project operates a comprehensive testing framework (available at tests.reproducible-builds.org) in order to check packages and other artifacts for reproducibility. In August, a number of changes were made by Holger Levsen:
  • Disable armhf and i386 builds due to Debian bug #1052257. [ ][ ][ ][ ]
  • Run diffoscope with a lower ionice priority. [ ]
  • Log every build in a simple text file [ ] and create persistent stamp files when running diffoscope to ease debugging [ ].
  • Run schedulers one hour after dinstall again. [ ]
  • Temporarily use diffoscope from the host, and not from a schroot running the tested suite. [ ][ ]
  • Fail the diffoscope distribution test if the diffoscope version cannot be determined. [ ]
  • Fix a spelling error in the email to IRC gateway. [ ]
  • Force (and document) the reconfiguration of all jobs, due to the recent rise of zombies. [ ][ ][ ][ ]
  • Deal with a rare condition when killing processes which should not be there. [ ]
  • Install the Debian backports kernel in an attempt to address Debian bug #1052257. [ ][ ]
In addition, Mattia Rizzolo fixed a call to diffoscope --version (as suggested by Fay Stegerman on our mailing list) [ ], worked on an openQA credential issue [ ] and also made some changes to the machine-readable reproducible metadata, reproducible-tracker.json [ ]. Lastly, Roland Clobus added instructions for manual configuration of the openQA secrets [ ].

If you are interested in contributing to the Reproducible Builds project, please visit our Contribute page on our website. However, you can get in touch with us via:

8 October 2023

Sahil Dhiman: Lap 24

Twenty-four is a big number. More than one/fourth (or more) of my life is behind me now. At this point, I truly feel like I have become an adult; mentally and physically. Another year seem to have gone by quickly. I still vividly remember writing 23 and Counting and here I m writing the next one so soon. Probably the lowest I felt ever on my birthday; with loss of Abraham and on the other hand, medical issues with a dear one. Didn t even felt like birthday was almost here. The loss of Abraham, taught me to care for people more and meet cherish everyone. I m grateful for all the people who supported and cared for me and others during times of grief when things went numb. Thank you! Also, for the first time ever, I went to office on my birthday. This probably would become a norm in coming years. Didn t felt like doing anything, so just went to office. The cake, wishes and calls kept coming in throughout the day. I m grateful for the all people around for remembering :) This year marked my first official job switch where I moved from MakeMyTrip to Unmukti as a GNU/Linux Network Systems engineer (that s a mouthful of a job role, I know) where I do anything and everything ranging from system admin, network engineering, a bit of social media, chronicling stuff on company blog and bringing up new applications as per requirement. Moving from MMT to Unmukti was a big cultural shift. From a full-blown corporate with more than 3 thousand employees to a small 5-person team. People still think I work for a startup on hearing the low head count, though Unmukti is a 13 year old organization. I get the freedom to work at my own pace and put my ideas in larger technical discussions, while also actively participating in the community, which I m truly grateful of. I go full geek here and almost everyone here is on the same spectrum, so things technical or societal discussions just naturally flow. The months of August-September again marked the Great Refresh. For reasons unforeseen, I have had to pack my stuff again and move, albeit to just next door for now, but that gave me the much need opportunity to sift through my belongings here. As usual, I threw a boatload of stuff which was of no use and/or just hogging space. My wardrobe cupboard finally got cleaned and sorted, with old and new clothes getting (re)discovered. The Refresh is always a pain with loads of collating stuff in carry worthy bags and hauling stuff but as usual, there s nothing else I can do other than just pack and move. This year also culminated our four plus years of work for organizing annual Debian conference, DebConf to India. DebConf23 happened in Kochi, Kerala from 3rd September to 17th September (including DebCamp). First concrete work to bring conference to India was done Raju Dev who made the first bid during DebConf18 in Hsinchu, Taiwan. We lost but won during the next year bid at DebConf19 Curitiba, Brazil in 2019. I joined the efforts after meeting the team online after DebConf20. Initially started with the publicity team, but we didn t need much publicity for event, I was later asked to join sponsors/fundraising team. That turned out to be quite an experience. Then the conference itself turned to be a good experience. More on that in an upcoming DebConf23 blog post, which will come eventually. After seeing how things work out in Debian in 2020, I had the goal to become a Debian Developer (DD) before DebConf23, which gave me almost three years to get involved and get recognized to become a DD. I was more excited to grab sahil AT debian.org, a short email with only my name and no number of characters after it. After, quite a while, I dropped the hope of become a DD because I wasn t successful in my attempts to meaningfully package and technically contribute to the project. But people in Debian India later convinced me that I have done enough to become a Debian Developer, non uploading, purely by showing up and helping around all for the Debian conferences. I applied and got sponsored (i.e. supported) for my request by srud and Praveen. Finally, on 23rd Feb, I officially became part of Debian project as 14th (at the moment) Debian Developer from India. Got sahil AT debian.org too :) For some grace, I also became a DD before DebConf23. Becoming a DD didn t change anything much though, I still believe, it might have helped secure me a job though. Also, worth mentioning is my increased interest in OpenStreetMap (OSM) mapping. I heavily mapped this year and went around for mapathon-meetups too. One step towards a better OSM and more community engagement around it. Looking back at my blog, this year around, it seems mostly dotted with Debian and one OSM post. Significant shift from the range of topics I use to write about in the past year but blogging this year wasn t a go-to activity. Other stuff kept me busy. Living in Gurugram has shown me many facades of life from which I was shielded or didn t come across earlier. It made me realize all the privileges which has helped me along the way, which became apparent while living almost alone here and managing thing by oneself.

7 October 2023

Andrew Cater: Point release weekend for Debian: two releases this weekend: 202311071653

Over in Cambridge with RattusRattus, Sledge, egw and Isy. Andy is very kindly putting us up.

We're almost all of the way through testing 12.2 and some of the way through testing 11.8.

It's a LONG day - heads down into laptops and relatively quiet - I think we're all tired and we've a way to go yet.


2 October 2023

Jonathan Dowland: Promotion

It's been quiet here (I hope to change that), but I want to share some good news: I've been promoted to Principal Software Engineer! Next February will start my 9th year with Red Hat. Time flies when you're having fun!

30 September 2023

Ian Jackson: DKIM: rotate and publish your keys

If you are an email system administrator, you are probably using DKIM to sign your outgoing emails. You should be rotating the key regularly and automatically, and publishing old private keys. I have just released dkim-rotate 1.0; dkim-rotate is a tool to do this key rotation and publication. If you are an email user, your email provider ought to be doing this. If this is not done, your emails are non-repudiable , meaning that if they are leaked, anyone (eg, journalists, haters) can verify that they are authentic, and prove that to others. This is not desirable (for you). Non-repudiation of emails is undesirable This problem was described at some length in Matthew Green s article Ok Google: please publish your DKIM secret keys. Avoiding non-repudiation sounds a bit like lying. After all, I m advising creating a situation where some people can t verify that something is true, even though it is. So I m advocating casting doubt. Crucially, though, it s doubt about facts that ought to be private. When you send an email, that s between you and the recipient. Normally you don t intend for anyone, anywhere, who happens to get a copy, to be able to verify that it was really you that sent it. In practical terms, this verifiability has already been used by journalists to verify stolen emails. Associated Press provide a verification tool. Advice for all email users As a user, you probably don t want your emails to be non-repudiable. (Other people might want to be able to prove you sent some email, but your email system ought to serve your interests, not theirs.) So, your email provider ought to be rotating their DKIM keys, and publishing their old ones. At a rough guess, your provider probably isn t :-(. How to tell by looking at email headers A quick and dirty way to guess is to have a friend look at the email headers of a message you sent. (It is important that the friend uses a different email provider, since often DKIM signatures are not applied within a single email system.) If your friend sees a DKIM-Signature header then the message is DKIM signed. If they don t, then it wasn t. Most email traversing the public internet is DKIM signed nowadays; so if they don t see the header probably they re not looking using the right tools, or they re actually on the same email system as you. In messages signed by a system running dkim-rotate, there will also be a header about the key rotation, to notify potential verifiers of the situation. Other systems that avoid non-repudiation-through-DKIM might do something similar. dkim-rotate s header looks like this:
DKIM-Signature-Warning: NOTE REGARDING DKIM KEY COMPROMISE
 https://www.chiark.greenend.org.uk/dkim-rotate/README.txt
 https://www.chiark.greenend.org.uk/dkim-rotate/ae/aeb689c2066c5b3fee673355309fe1c7.pem
But an email system might do half of the job of dkim-rotate: regularly rotating the key would cause the signatures of old emails to fail to verify, which is a good start. In that case there probably won t be such a header. Testing verification of new and old messages You can also try verifying the signatures. This isn t entirely straightforward, especially if you don t have access to low-level mail tooling. Your friend will need to be able to save emails as raw whole headers and body, un-decoded, un-rendered. If your friend is using a traditional Unix mail program, they should save the message as an mbox file. Otherwise, ProPublica have instructions for attaching and transferring and obtaining the raw email. (Scroll down to How to Check DKIM and ARC .) Checking that recent emails are verifiable Firstly, have your friend test that they can in fact verify a DKIM signature. This will demonstrate that the next test, where the verification is supposed to fail, is working properly and fails for the right reasons. Send your friend a test email now, and have them do this on a Linux system:
    # save the message as test-email.mbox
    apt install libmail-dkim-perl # or equivalent on another distro
    dkimproxy-verify <test-email.mbox
You should see output containing something like this:
    originator address: ijackson@chiark.greenend.org.uk
    signature identity: @chiark.greenend.org.uk
    verify result: pass
    ...
If the output ontains verify result: fail (body has been altered) then probably your friend didn t manage to faithfully save the unalterered raw message. Checking old emails cannot be verified When you both have that working, have your friend find an older email of yours, from (say) month ago. Perform the same steps. Hopefully they will see something like this:
    originator address: ijackson@chiark.greenend.org.uk
    signature identity: @chiark.greenend.org.uk
    verify result: fail (bad RSA signature)
or maybe
    verify result: invalid (public key: not available)
This indicates that this old email can no longer be verified. That s good: it means that anyone who steals a copy, can t verify it either. If it s leaked, the journalist who receives it won t know it s genuine and unmodified; they should then be suspicious. If your friend sees verify result: pass, then they have verified that that old email of yours is genuine. Anyone who had a copy of the mail can do that. This is good for email thieves, but not for you. For email admins: announcing dkim-rotate 1.0 I have been running dkim-rotate 0.4 on my infrastructure, since last August. and I had entirely forgotten about it: it has run flawlessly for a year. I was reminded of the topic by seeing DKIM in other blog posts. Obviously, it is time to decreee that dkim-rotate is 1.0. If you re a mail system administrator, your users are best served if you use something like dkim-rotate. The package is available in Debian stable, and supports Exim out of the box, but other MTAs should be easy to support too, via some simple ad-hoc scripting. Limitation of this approach Even with this key rotation approach, emails remain nonrepudiable for a short period after they re sent - typically, a few days. Someone who obtains a leaked email very promptly, and shows it to the journalist (for example) right away, can still convince the journalist. This is not great, but at least it doesn t apply to the vast bulk of your email archive. There are possible email protocol improvements which might help, but they re quite out of scope for this article.
Edited 2023-10-01 00:20 +01:00 to fix some grammar


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