The Guile bindings for GnuTLS has been part of GnuTLS since spring 2007 when Ludovic Court s contributed it after some initial discussion. I have been looking into getting back to do GnuTLS coding, and during a recent GnuTLS meeting one topic was Guile bindings. It seemed like a fairly self-contained project to pick up on. It is interesting to re-read the old thread when this work was included: some of the concerns brought up there now have track record to be evaluated on. My opinion that the cost of introducing a new project per language binding today is smaller than the cost of maintaining language bindings as part of the core project. I believe the cost/benefit ratio has changed during the past 15 years: introducing a new project used to come with a significant cost but this is no longer the case, as tooling and processes for packaging have improved. I have had similar experience with Java, C# and Emacs Lisp bindings for GNU Libidn as well, where maintaining them centralized slow down the pace of updates. Andreas Metzler pointed to a similar conclusion reached by Russ Allbery. There are many ways to separate a project into two projects; just copying the files into a new git repository would have been the simplest and was my original plan. However Ludo mentioned git-filter-branch in an email, and the idea of keeping all git history for some of the relevant files seemed worth pursuing to me. I quickly found git-filter-repo which appears to be the recommend approach, and experimenting with it I found a way to filter out the GnuTLS repo into a small git repository that Guile-GnuTLS could be based on. The commands I used were the following, if you want to reproduce things.

$ git clone https://gitlab.com/gnutls/gnutls.git guile-gnutls
$ cd guile-gnutls/
$ git checkout f5dcbdb46df52458e3756193c2a23bf558a3ecfd
$ git-filter-repo --path guile/ --path m4/guile.m4 --path doc/gnutls-guile.texi --path doc/extract-guile-c-doc.scm --path doc/cha-copying.texi --path doc/fdl-1.3.texi

I debated with myself back and forth whether to include some files that would be named the same in the new repository but would share little to no similar lines, for example configure.ac, Makefile.am not to mention README and NEWS. Initially I thought it would be nice to preserve the history for all lines that went into the new project, but this is a subjective judgement call. What brought me over to a more minimal approach was that the contributor history and attribution would be quite strange for the new repository: Should Guile-GnuTLS attribute the work of the thousands of commits to configure.ac which had nothing to do with Guile? Should the people who wrote that be mentioned as contributor of Guile-GnuTLS? I think not. The next step was to get a reasonable GitLab CI/CD pipeline up, to make sure the project builds on some free GNU/Linux distributions like Trisquel and PureOS as well as the usual non-free distributions like Debian and Fedora to have coverage of dpkg and rpm based distributions. I included builds on Alpine and ArchLinux as well, because they tend to trigger other portability issues. I wish there were GNU Guix docker images available for easy testing on that platform as well. The GitLab CI/CD rules for a project like this are fairly simple. To get things out of the door, I tagged the result as v3.7.9 and published a GitLab release page for Guile-GnuTLS that includes OpenPGP-signed source tarballs manually uploaded built on my laptop. The URLs for these tarballs are not very pleasant to work with, and discovering new releases automatically appears unreliable, but I don t know of a better approach. To finish this project, I have proposed a GnuTLS merge request to remove all Guile-related parts from the GnuTLS core. Doing some GnuTLS-related work again felt nice, it was quite some time ago so thank you for giving me this opportunity. Thoughts or comments? Happy hacking!

Debian does not officially support upgrading from earlier than the previous stable release: you re not supposed to skip releases. Instead, you re supposed to upgrade to each intervening major release in turn. However, skipping intervening releases does, in fact, often work quite well. Apparently, this is surprising to many people, even Debian insiders. I was encouraged to write about it some more. My personal experience I have three conventionally-managed personal server systems (by which I mean systems which aren t reprovisioned by some kind of automation). Of these at least two have been skip upgraded at least once: The one I don t think I ve skip-upgraded (at least, not recently) is my house network manager (and now VM host) which I try to keep to a minimum in terms of functionality and which I keep quite up to date. It was crossgraded from i386 (32-bit) to amd64 (64-bit) fairly recently, which is a thing that Debian isn t sure it supports. The crossgrade was done a hurry and without any planning, prompted by Spectre et al suddenly requiring big changes to Xen. But it went well enough. My home does random stuff server (media server, web cache, printing, DNS, backups etc.), has etckeeper records starting in 2015. I upgraded directly from jessie (Debian 8) to buster (Debian 10). I think it has probably had earlier skip upgrade(s): the oldest file in /etc is from December 1996 and I have been doing occasional skip upgrades as long as I can remember. And of course there s chiark, which is one of the oldest Debian installs in existence. I wrote about the most recent upgrade, where I went directly from jessie i386 ELTS (32-bit Debian 8) to bulleye amd64 (64-bit Debian 11). That was a very extreme case which required significant planning and pre-testing, since the package dependencies were in no way sufficient for the proper ordering. But, I don t normally go to such lengths. Normally, even on chiark, I just edit the sources.list and see what apt proposes to do. I often skip upgrade chiark because I tend to defer risky-looking upgrades partly in the hope of others fixing the bugs while I wait :-), and partly just because change is disruptive and amortising it is very helpful both to me and my users. I have some records of chiark s upgrades from my announcements to users. As well as the recent skip skip up cross grade, direct , I definitely did a skip upgrade of chiark from squeeze (Debian 6) to jessie (Debian 8). It appears that the previous skip upgrade on chiark was rex (Debian 1.2) to hamm (Debian 2.0). I don t think it s usual for me to choose to do a multi-release upgrade the officially supported way, in two (or more) stages, on a server. I have done that on systems with a GUI desktop setup, but even then I usually skip the intermediate reboot(s). When to skip upgrade (and what precautions to take) I m certainly not saying that everyone ought to be doing this routinely. Most users with a Debian install that is older than oldstable probably ought to reinstall it, or do the two-stage upgrade. Skip upgrading almost always runs into some kind of trouble (albeit, usually trouble that isn t particularly hard to fix if you know what you re doing). However, officially supported non-skip upgrades go wrong too. Doing a two-or-more-releases upgrade via the intermediate releases can expose you to significant bugs in the intermediate releases, which were later fixed. Because Debian s users and downstreams are cautious, and Debian itself can be slow, it is common for bugs to appear for one release and then be fixed only in the next. Paradoxically, this seems to be especially true with the kind of big and scary changes where you d naively think the upgrade mechanisms would break if you skipped the release where the change first came in. I would not recommend a skip upgrade to someone who is not a competent Debian administrator, with good familiarity with Debian package management, including use of dpkg directly to fix things up. You should have a mental toolkit of manual bug workaround techniques. I always should make sure that I have rescue media (and in the case of a remote system, full remote access including ability to boot a different image), although I don t often need it. And, when considering a skip upgrade, you should be aware of the major changes that have occurred in Debian. Skip upgrading is more likely to be a good idea with a complex and highly customised system: a fairly vanilla install is not likely to encounter problems during a two-stage update. (And, a vanilla system can be upgraded by reinstalling.) I haven t recently skip upgraded a laptop or workstation. I doubt I would attempt it; modern desktop software seems to take a much harder line about breaking things that are officially unsupported, and generally trying to force everyone into the preferred mold. A request to Debian maintainers I would like to encourage Debian maintainers to defer removing upgrade compatibility machinery until it is actually getting in the way, or has become hazardous, or many years obsolete. Examples of the kinds of things which it would be nice to keep, and which do not usually cause much inconvenience to retain, are dependency declarations (particularly, alternatives), and (many) transitional fragments in maintainer scripts. If you find yourself needing to either delete some compatibility feature, or refactor/reorganise it, I think it is probably best to delete it. If you modify it significantly, the resulting thing (which won t be tested until someone uses it in anger) is quite likely to have bugs which make it go wrong more badly (or, more confusingly) than the breakage that would happen without it. Obviously this is all a judgement call. I m not saying Debian should formally support skip upgrades, to the extent of (further) slowing down important improvements. Nor am I asking for any change to the routine approach to (for example) transitional packages (i.e. the technique for ensuring continuity of installation when a package name changes). We try to make release upgrades work perfectly; but skip upgrades don t have to work perfectly to be valuable. Retaining compatibility code can also make it easier to provide official backports, and it probably helps downstreams with different release schedules. The fact that maintainers do in practice often defer removing compatibility code provides useful flexibility and options to at least some people. So it would be nice if you d at least not go out of your way to break it. Building on older releases I would also like to encourage maintainers to provide source packages in Debian unstable that will still build on older releases, where this isn t too hard and the resulting binaries might be basically functional. Speaking personally, it s not uncommon for me to rebuild packages from unstable and install them on much older releases. This is another thing that is not officially supported, but which often works well. I m not saying to contort your build system, or delay progress. You ll definitely want to depend on a recentish debhelper. But, for example, retaining old build-dependency alternatives is nice. Retaining them doesn t constitute a promise that it works - it just makes life slightly easier for someone who is going off piste. If you know you have users on multiple distros or multiple releases, and wish to fully support them, you can go further, of course. Many of my own packages are directly buildable, or even directly installable, on older releases.

comments

LaTeX the age-old typesetting system makes me angry. Not because it's bad. To clarify, not because there's something better. But because there should be. When writing a document using LaTeX, if you are prone to procrastination it can be very difficult to focus on the task at hand, because there are so many yaks to shave. Here's a few points of advice.

• format the document source for legible reading. Yes, it's the input to the typesetter, and yes, the output of the typesetter needs to be legible. But it's worth making the input easy to read, too. Because
• avoid rebuilding your rendered document too often. It's slow, it takes you out of the activity of writing, and it throws up lots of opportunities to get distracted by some rendering nit that you didn't realise would happen.
• Unless you are very good at manoeuvring around long documents, liberally split them up. I think it's fine to have sections in their own source files.
• Machine-assisted moving around documents is good. If you use (neo)vim, you can tweak exuberant-ctags to generate more useful tags for LaTeX documents than what you get OOTB, including jumping to \label s and the BibTeX source of \cite s. See this stackoverflow post.
• If you use syntax highlighting in your editor, take a long, hard look at what it's drawing attention to. It's not your text, that's for sure. Is it worth having it on? Consider turning it off. Or (yak shaving beware!) tweak it to de-emphasise things, instead of emphasising them. One small example for (neo)vim, to change tokens recognised as being "todo" to match the styling used for comments (which is normally de-emphasised):

  hi def link texTodo Comment
  

In a nutshell, I think it's wise to move much document reviewing work back into the editor rather than the rendered document, at least in the early stages of a section. And to do that, you need the document to be as legible as possible in the editor. The important stuff is the text you write, not the TeX macros you've sprinkled around to format it. A few tips I benefit from in terms of source formatting:

• I stick a line of 78 '%' characters between each section and sub-section. This helps to visually break them up and finding them in a scroll-past is quicker.
• I indent as much of the content as I can in each chapter/section/subsection (however deep I go in sections) to tie them to the section they belong to and see at a glance how deep I am in subsections, just like with source code. The exception is environments that I can't due to other tool limitations: I have code excerpts demarked by \begin code /\end code which are executed by Haskell's GHCi interpreter, and the indentation can interfere with Haskell's indentation rules.
• For large documents (like a thesis), I have little helper "standalone" .tex files whose purpose is to let me build just one chapter or section at a time.
• I'm fairly sure I'll settle on a serif font for my final document. But I have found that a sans-serif font is easier on my eyes on-screen. YMMV.

Of course, you need to review the rendered document too! I like to bounce that to a tablet with a pen/stylus/pencil and review it in a different environment to where I write. I then end up with a long list of scrawled notes, and a third distinct activity, back at the writing desk, is to systematically go through them and apply some GTD-style thinking to them: can I fix it in a few seconds? Do it straight away. Delegate it? Unlikely Defer it? transfer the review note into another system of record (such as LaTeX \\todo ). And finally

• Don't stop to write a blog post about it.

Welcome to the September 2022 report from the Reproducible Builds project! In our reports we try to 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. If you are interested in contributing to the project, please visit our Contribute page on our website.

---

David A. Wheeler reported to us that the US National Security Agency (NSA), Cybersecurity and Infrastructure Security Agency (CISA) and the Office of the Director of National Intelligence (ODNI) have released a document called Securing the Software Supply Chain: Recommended Practices Guide for Developers (PDF). As David remarked in his post to our mailing list, it expressly recommends having reproducible builds as part of advanced recommended mitigations . The publication of this document has been accompanied by a press release.

---

Holger Levsen was made aware of a small Microsoft project called oss-reproducible. Part of, OSSGadget, a larger collection of tools for analyzing open source packages , the purpose of oss-reproducible is to:

analyze open source packages for reproducibility. We start with an existing package (for example, the NPM left-pad package, version 1.3.0), and we try to answer the question, Do the package contents authentically reflect the purported source code?

More details can be found in the README.md file within the code repository.

---

David A. Wheeler also pointed out that there are some potential upcoming changes to the OpenSSF Best Practices badge for open source software in relation to reproducibility. Whilst the badge programme has three certification levels ( passing , silver and gold ), the gold level includes the criterion that The project MUST have a reproducible build . David reported that some projects have argued that this reproducibility criterion should be slightly relaxed as outlined in an issue on the best-practices-badge GitHub project. Essentially, though, the claim is that the reproducibility requirement doesn t make sense for projects that do not release built software, and that timestamp differences by themselves don t necessarily indicate malicious changes. Numerous pragmatic problems around excluding timestamps were raised in the discussion of the issue.

---

Sonatype, a pioneer of software supply chain management , issued a press release month to report that they had found:

[ ] a massive year-over-year increase in cyberattacks aimed at open source project ecosystems. According to early data from Sonatype s 8th annual State of the Software Supply Chain Report, which will be released in full this October, Sonatype has recorded an average 700% jump in repository attacks over the last three years.

More information is available in the press release.

---

A number of changes were made to the Reproducible Builds website and documentation this month, including Chris Lamb adding a redirect from /projects/ to /who/ in order to keep old or archived links working [ ], Jelle van der Waa added a Rust programming language example for SOURCE_DATE_EPOCH [ ][ ] and Mattia Rizzolo included Protocol Labs amongst our project-level sponsors [ ].

Debian There was a large amount of reproducibility work taking place within Debian this month:

• The nfft source package was removed from the archive, and now all packages in Debian bookworm now have a corresponding .buildinfo file. This can be confirmed and tracked on the associated page on the tests.reproducible-builds.org site.
• Vagrant Cascadian announced on our mailing list an informal online sprint to help clear the huge backlog of reproducible builds patches submitted by performing NMU (Non-Maintainer Uploads). The first such sprint took place on September 22nd with the following results:
  • Holger Levsen:
    • Mailed #1010957 in man-db asking for an update and whether to remove the patch tag for now. This was subsequently removed and the maintainer started to address the issue.
    • Uploaded gmp to DELAYED/15, fixing #1009931.
    • Emailed #1017372 in plymouth and asked for the maintainer s opinion on the patch. This resulted in the maintainer improving Vagrant s original patch (and uploading it) as well as filing an issue upstream.
    • Uploaded time to DELAYED/15, fixing #983202.
  • Vagrant Cascadian:
    • Verify and updated patch for mylvmbackup (#782318)
    • Verified/updated patches for libranlip. (#788000, #846975 & #1007137)
    • Uploaded libranlip to DELAYED/10.
    • Verified patch for cclive. (#824501)
    • Uploaded cclive to DELAYED/10.
    • Vagrant was unable to reproduce the underlying issue within #791423 (linuxtv-dvb-apps) and so the bug was marked as done .
    • Researched #794398 (in clhep).
  The plan is to repeat these sprints every two weeks, with the next taking place on Thursday October 6th at 16:00 UTC on the #debian-reproducible IRC channel.
• Roland Clobus posted his 13th update of the status of reproducible Debian ISO images on our mailing list. During the last month, Roland ensured that the live images are now automatically fed to openQA for automated testing after they have been shown to be reproducible. Additionally Roland asked on the debian-devel mailing list about a way to determine the canonical timestamp of the Debian archive. [ ]
• Following up on last month s work on reproducible bootstrapping, Holger Levsen filed two bugs against the debootstrap and cdebootstrap utilities. (#1019697 & #1019698)

Lastly, 44 reviews of Debian packages were added, 91 were updated and 17 were removed this month adding to our knowledge about identified issues. A number of issue types have been updated too, including the descriptions of cmake_rpath_contains_build_path [ ], nondeterministic_version_generated_by_python_param [ ] and timestamps_in_documentation_generated_by_org_mode [ ]. Furthermore, two new issue types were created: build_path_used_to_determine_version_or_package_name [ ] and captures_build_path_via_cmake_variables [ ].

Other distributions In openSUSE, Bernhard M. Wiedemann published his usual openSUSE monthly report.

diffoscope diffoscope is our in-depth and content-aware diff utility. Not only can it locate and diagnose reproducibility issues, it can provide human-readable diffs from many kinds of binary formats. This month, Chris Lamb prepared and uploaded versions 222 and 223 to Debian, as well as made the following changes:

• The cbfstools utility is now provided in Debian via the coreboot-utils package so we can enable that functionality within Debian. [ ]
• Looked into Mach-O support.
• Fixed the try.diffoscope.org service by addressing a compatibility issue between glibc/seccomp that was preventing the Docker-contained diffoscope instance from spawning any external processes whatsoever [ ]. I also updated the requirements.txt file, as some of the specified packages were no longer available [ ][ ].

In addition Jelle van der Waa added support for file version 5.43 [ ] and Mattia Rizzolo updated the packaging:

• Also include coreboot-utils in the Build-Depends and Test-Depends fields so that it is available for tests. [ ]
• Use pep517 and pip to load the requirements. [ ]
• Remove packages in Breaks/Replaces that have been obsoleted since the release of Debian bullseye. [ ]

Reprotest reprotest is our end-user tool to build the same source code twice in widely and deliberate different environments, and checking whether the binaries produced by the builds have any differences. This month, reprotest version 0.7.22 was uploaded to Debian unstable by Holger Levsen, which included the following changes by Philip Hands:

• Actually ensure that the setarch(8) utility can actually execute before including an architecture to test. [ ]
• Include all files matching *.*deb in the default artifact_pattern in order to archive all results of the build. [ ]
• Emit an error when building the Debian package if the Debian packaging version does not patch the Python version of reprotest. [ ]
• Remove an unneeded invocation of the head(1) utility. [ ]

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:

• Bernhard M. Wiedemann (18 bugs):
  • DateTime (fails to build in 2038)
  • FreeRCT (date-related issue)
  • clanlib1 (filesystem ordering)
  • cli (fails to build in 2038)
  • deepin-gettext-tools (patch+version update toolchain sort python glob)
  • mariadb (fails to build in 2038)
  • mercurial (fails to build in 2038)
  • mirrormagic (parallelism-related issue)
  • ocaml-extlib (parallelism-related issue)
  • python-xmlrpc/python-softlayer (fails to build in 2038)
  • python (fails to build in 2038)
  • q3rally (zip-related issue)
  • rnd_jue (parallelism-related issue)
  • rsync (workaround an issue in GCC 7.x)
  • scons (SOURCE_DATE_EPOCH-related issue)
  • stratagus (date-related issue)
  • triplane (nondeterminism caused by uninitialised memory)
  • tyrquake (date-related issue)
• Chris Lamb:
  • #1019382 filed against gnome-online-accounts.
  • There was renewed activity on a reproducibility-related bug in the Sphinx documentation tool this month. Originally filed in October 2021 by Chris Lamb, the bug in question relates to contents of the LANGUAGE environment variable inconsistently affecting the output of objects.inv files.
• Jelle van der Waa:
  • mp4v2 (date-related issue)
  • mm-common (uid/gid issue)
  • aardvark-dns (date-related issue)
• Vagrant Cascadian (70 bugs!):
  • #1020648 filed against extrepo-data.
  • #1020650 filed against tmpreaper.
  • #1020651 filed against xmlrpc-epi.
  • #1020653 filed against pal.
  • #1020656 filed against nvram-wakeup.
  • #1020657 filed against netris.
  • #1020658 filed against netpbm-free.
  • #1020659 filed against lookup.
  • #1020660 filed against logtools.
  • #1020661 filed against libid3tag.
  • #1020662 filed against log4cpp.
  • #1020665 filed against libimage-imlib2-perl.
  • #1020668 filed against jnettop.
  • #1020670 filed against gwaei.
  • #1020671 filed against ipfm.
  • #1020672 filed against tarlz.
  • #1020673 filed against w3cam.
  • #1020674 filed against ifstat.
  • #1020715 filed against xserver-xorg-input-joystick.
  • #1020719 filed against chibicc.
  • #1020723 filed against python-omegaconf.
  • #1020724 and #1020725 filed against snapper.
  • #1020736 filed against libreswan.
  • #1020743 filed against pure-ftpd.
  • #1020748 filed against xcolmix.
  • #1020749 filed against gigalomania.
  • #1020750 filed against xjump.
  • #1020751 filed against waili.
  • #1020752 filed against sjeng.
  • #1020753 filed against seqtk.
  • #1020754 filed against shapetools.
  • #1020755 filed against rotter.
  • #1020756 filed against rakarrack.
  • #1020757 filed against rig.
  • #1020759 filed against postal.
  • #1020798 filed against netkit-rsh.
  • #1020800 filed against libapache-mod-evasive.
  • #1020804 filed against paxctl.
  • #1020805 filed against png23d.
  • #1020806 filed against perl-byacc.
  • #1020807 filed against poster.
  • #1020808 filed against powerdebug.
  • #1020809 filed against aespipe.
  • #1020810 filed against aewm++-goodies.
  • #1020811 filed against apache-upload-progress-module.
  • #1020812 filed against ascii2binary.
  • #1020813 filed against bible-kjv.
  • #1020814 filed against dradio.
  • #1020815 filed against libapache2-mod-python.
  • #1020816 filed against tempest-for-eliza.
  • #1020817 filed against aplus-fsf.
  • #1020866 filed against wrapsrv.
  • #1020867 filed against uclibc.
  • #1020870 filed against xppaut.
  • #1020872 filed against xvier.
  • #1020873 filed against xserver-xorg-video-glide.
  • #1020875 filed against z80asm.
  • #1020876 filed against yaskkserv.
  • #1020877 filed against edid-decode.
  • #1020878 filed against dustmite.
  • #1020879 filed against dustmite.
  • #1020880 filed against libapache2-mod-authnz-pam.
  • #1020881 filed against kafs-client.
  • #1020882 filed against yaku-ns.
  • #1020884 filed against bplay.
  • #1020886 filed against chise-base.
  • #1020887 filed against checkpw.
  • #1020888 filed against clamz.
  • #1020889 filed against libapache2-mod-auth-pgsql.

Testing framework The Reproducible Builds project runs a significant testing framework at tests.reproducible-builds.org in order to check packages and other artifacts for reproducibility. This month, however, the following changes were made:

• Holger Levsen:
  • Add a job to build reprotest from Git [ ] and use the correct Git branch when building it [ ].
• Mattia Rizzolo:
  • Enable syncing of results from building live Debian ISO images. [ ]
  • Use scp -p in order to preserve modification times when syncing live ISO images. [ ]
  • Apply the shellcheck shell script analysis tool. [ ]
  • In a build node wrapper script, remove some debugging code which was messing up calling scp(1) correctly [ ] and consquently add support to use both scp -p and regular scp [ ].
• Roland Clobus:
  • Track and handle the case where the Debian archive gets updated between two live image builds. [ ]
  • Remove a call to sudo(1) as it is not (or no longer) required to delete old live-build results. [ ]

Contact As ever, 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:

• IRC: #reproducible-builds on irc.oftc.net.
• Twitter: @ReproBuilds
• Mailing list: rb-general@lists.reproducible-builds.org

Fast laptops are expensive, cheap laptops are slow. But even a fast laptop is slower than a decent workstation, and if your developers want a local build environment they're probably going to want a decent workstation. They'll want a fast (and expensive) laptop as well, though, because they're not going to carry their workstation home with them and obviously you expect them to be able to work from home. And in two or three years they'll probably want a new laptop and a new workstation, and that's even more money. Not to mention the risks associated with them doing development work on their laptop and then drunkenly leaving it in a bar or having it stolen or the contents being copied off it while they're passing through immigration at an airport. Surely there's a better way?

This is the thinking that leads to "Let's give developers a Chromebook and a VM running in the cloud". And it's an appealing option! You spend far less on the laptop, and the VM is probably cheaper than the workstation - you can shut it down when it's idle, you can upgrade it to have more CPUs and RAM as necessary, and you get to impose all sorts of additional neat security policies because you have full control over the network. You can run a full desktop environment on the VM, stream it to a cheap laptop, and get the fast workstation experience on something that weighs about a kilogram. Your developers get the benefit of a fast machine wherever they are, and everyone's happy.

But having worked at more than one company that's tried this approach, my experience is that very few people end up happy. I'm going to give a few reasons here, but I can't guarantee that they cover everything - and, to be clear, many (possibly most) of the reasons I'm going to describe aren't impossible to fix, they're simply not priorities. I'm also going to restrict this discussion to the case of "We run a full graphical environment on the VM, and stream that to the laptop" - an approach that only offers SSH access is much more manageable, but also significantly more restricted in certain ways. With those details mentioned, let's begin.

The first thing to note is that the overall experience is heavily tied to the protocol you use for the remote display. Chrome Remote Desktop is extremely appealing from a simplicity perspective, but is also lacking some extremely key features (eg, letting you use multiple displays on the local system), so from a developer perspective it's suboptimal. If you read the rest of this post and want to try this anyway, spend some time working with your users to find out what their requirements are and figure out which technology best suits them.

Second, let's talk about GPUs. Trying to run a modern desktop environment without any GPU acceleration is going to be a miserable experience. Sure, throwing enough CPU at the problem will get you past the worst of this, but you're still going to end up with users who need to do 3D visualisation, or who are doing VR development, or who expect WebGL to work without burning up every single one of the CPU cores you so graciously allocated to their VM. Cloud providers will happily give you GPU instances, but that's going to cost more and you're going to need to re-run your numbers to verify that this is still a financial win. "But most of my users don't need that!" you might say, and we'll get to that later on.

Next! Video quality! This seems like a trivial point, but if you're giving your users a VM as their primary interface, then they're going to do things like try to use Youtube inside it because there's a conference presentation that's relevant to their interests. The obvious solution here is "Do your video streaming in a browser on the local system, not on the VM" but from personal experience that's a super awkward pain point! If I click on a link inside the VM it's going to open a browser there, and now I have a browser in the VM and a local browser and which of them contains the tab I'm looking for WHO CAN SAY. So your users are going to watch stuff inside their VM, and re-compressing decompressed video is going to look like shit unless you're throwing a huge amount of bandwidth at the problem. And this is ignoring the additional irritation of your browser being unreadable while you're rapidly scrolling through pages, or terminal output from build processes being a muddy blur of artifacts, or the corner case of "I work for Youtube and I need to be able to examine 4K streams to determine whether changes have resulted in a degraded experience" which is a very real job and one that becomes impossible when you pass their lovingly crafted optimisations through whatever codec your remote desktop protocol has decided to pick based on some random guesses about the local network, and look everyone is going to have a bad time.

The browser experience. As mentioned before, you'll have local browsers and remote browsers. Do they have the same security policy? Who knows! Are all the third party services you depend on going to be ok with the same user being logged in from two different IPs simultaneously because they lost track of which browser they had an open session in? Who knows! Are your users going to become frustrated? Who knows oh wait no I know the answer to this one, it's "yes".

Accessibility! More of your users than you expect rely on various accessibility interfaces, be those mechanisms for increasing contrast, screen magnifiers, text-to-speech, speech-to-text, alternative input mechanisms and so on. And you probably don't know this, but most of these mechanisms involve having accessibility software be able to introspect the UI of applications in order to provide appropriate input or expose available options and the like. So, I'm running a local text-to-speech agent. How does it know what's happening in the remote VM? It doesn't because it's just getting an a/v stream, so you need to run another accessibility stack inside the remote VM and the two of them are unaware of each others existence and this works just as badly as you'd think. Alternative input mechanism? Good fucking luck with that, you're at best going to fall back to "Send synthesized keyboard inputs" and that is nowhere near as good as "Set the contents of this text box to this unicode string" and yeah I used to work on accessibility software maybe you can tell. And how is the VM going to send data to a braille output device? Anyway, good luck with the lawsuits over arbitrarily making life harder for a bunch of members of a protected class.

One of the benefits here is supposed to be a security improvement, so let's talk about WebAuthn. I'm a big fan of WebAuthn, given that it's a multi-factor authentication mechanism that actually does a good job of protecting against phishing, but if my users are running stuff inside a VM, how do I use it? If you work at Google there's a solution, but that does mean limiting yourself to Chrome Remote Desktop (there are extremely good reasons why this isn't generally available). Microsoft have apparently just specced a mechanism for doing this over RDP, but otherwise you're left doing stuff like forwarding USB over IP, and that means that your USB WebAuthn no longer works locally. It also doesn't work for any other type of WebAuthn token, such as a bluetooth device, or an Apple TouchID sensor, or any of the Windows Hello support. If you're planning on moving to WebAuthn and also planning on moving to remote VM desktops, you're going to have a bad time.

That's the stuff that comes to mind immediately. And sure, maybe each of these issues is irrelevant to most of your users. But the actual question you need to ask is what percentage of your users will hit one or more of these, because if that's more than an insignificant percentage you'll still be staffing all the teams that dealt with hardware, handling local OS installs, worrying about lost or stolen devices, and the glorious future of just being able to stop worrying about this is going to be gone and the financial benefits you promised would appear are probably not going to work out in the same way.

A lot of this falls back to the usual story of corporate IT - understand the needs of your users and whether what you're proposing actually meets them. Almost everything I've described here is a corner case, but if your company is larger than about 20 people there's a high probability that at least one person is going to fall into at least one of these corner cases. You're going to need to spend a lot of time understanding your user population to have a real understanding of what the actual costs are here, and I haven't seen anyone do that work before trying to launch this and (inevitably) going back to just giving people actual computers.

There are alternatives! Modern IDEs tend to support SSHing out to remote hosts to perform builds there, so as long as you're ok with source code being visible on laptops you can at least shift the "I need a workstation with a bunch of CPU" problem out to the cloud. The laptops are going to need to be more expensive because they're also going to need to run more software locally, but it wouldn't surprise me if this ends up being cheaper than the full-on cloud desktop experience in most cases.

Overall, the most important thing to take into account here is that your users almost certainly have more use cases than you expect, and this sort of change is going to have direct impact on the workflow of every single one of your users. Make sure you know how much that's going to be, and take that into consideration when suggesting it'll save you money.

comments

I work on OpenJDK backports: taking a patch that was committed to a current version of JDK, and adapting it to an older one. There are four main OpenJDK versions that I am concerned with: the current version ("jdk"), 8, 11 and 17. These are all maintained in separate Git(Hub) repositories. It's very useful to have access to the other JDKs when working on any particular version. For example, to backport a patch from the latest version to 17, where the delta is not too big, a lot of the time you can cherry-pick the patch unmodified. To do git cherry-pick <some-commit> in a git repository tracking JDK17, where <some-commit> is in "jdk", I need the "jdk" repository configured as a remote for my local jdk17 repository. Maintaining completely separate local git repositories for all four JDK versions, with each of them having a subset of the others added as remotes, adds up to a lot of duplicated data on local storage. For a little while I was exploring using shared clones: a local clone of another local git repository which share some local metadata. This saves on some disc space, but it does not share the configuration for remotes: so I still have to add any other JDK versions I want as remotes in each shared clone (even if the underlying objects already exist in the shared metadata) Then I discovered git worktree. The git repositories that I've used up until now have had exactly zero (for a bare clone) or one worktree: in other words, the check-out, the actual source code files. Git does actually support having more than one worktree, which can be achieved like so:

git worktree add --checkout \
    -b jdk8u-master \
    ../jdk.worktree.jdk8u \
    jdk8u-dev/master

The result (in this example) is a new checkout, in this case of a new local branch named jdk8u-master at the sibling directory path jdk.worktree.jdk8u, tracking the remote branch jdk8u-dev/master. Within that checkout, there is a file .git which contains a pointer to (indirectly) the main local repository path:

gitdir: /home/jon/rh/git/jdk/.git/worktrees/jdk.worktree.jdk8u-dev

The directory itself behaves exactly like the real one, in that I can see all the configured remotes, and other checked out branches in other worktree paths:

$ git branch
  JDK-8214520-11u                               + 8284977-jdk11u-dev
  JDK-8268362-11u                               + master
  8231111-jdk11u-merged                         * 8237479-jdk8u-dev

Above, you can see that the current worktree is the branch 8237479-jdk8u-dev, marked (as usual) by the prefix *, and two other branches are checked out in other worktrees, marked by the prefix +. I only need to configure one local git repository with all of the remotes I am concerned about; I can inspect, compare, cherry-pick, check out, etc. any objects from any of those branches from any of my work trees; there's only one .git directory with all the configuration and storage for the git blobs across all the versions.

Almost to the week one year since the last maintenance release, we can announce another maintenance release, now at version 0.0.17, of the RVowpalWabbit package. The CRAN maintainers kindly and politly pointed out that I was (cough, cough) apparently the last maintainer who had packages that set StagedInstall: no. Guilty as charged. RVowpalWabbit is one the two packages; the other one will hopefully follow shortly . And while I long suspected linking aspects to drive this (this is an old package, newer R packaging of the awesome VowpalWabbit is in rvw, I was plain wrong here. The cause was an absolute path to an included dataset, computed in an example, which then gets serialized. As Tomas Kalibera suggested, we can replace the constant with a function and all is well. So here is 0.0.17. As noted before, there is a newer package rvw based on the excellent GSoC 2018 and beyond work by Ivan Pavlov (mentored by James and myself) so if you are into VowpalWabbit from R go check it out. CRANberries provides a summary of changes to the previous version. More information is on the RVowpalWabbit page. Issues and bugreports should go to the GitHub issue tracker. 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.

I've begun writing up my phd and, not for the first time, I'm pondering issues of how best to represent things. Specifically, rewrite rules. Here's one way of representing an example rewrite rule:

streamFilter g . streamFilter f = streamFilter (g . f)

This is a fairly succinct representation. It's sort-of Haskell, but not quite. It's an equation. The left-hand side is a pattern: it's intended to describe not one expression but a family of expressions that match. The lower case individual letters g and f are free variables: labelled placeholders within the pattern that can be referred to on the right hand side. I haven't stipulated what defines a free variable and what is a more concrete part of the pattern. It's kind-of Haskell, and I've used the well-known operator . to represent the two stream operators (streamFilters) being connected together. (In practice, when we get to the system where rules are actually applied, the connecting operator is not going to be . at all, so this is also an approximation). One thing I don't like about . here, despite its commonness, is having to read right-to-left. I adopted the habit of using the lesser-known >>> in a lot of my work (which is defined as (>>>) = flip (.)), which reads left-to-right. And then I have the reverse problem: people aren't familiar with >>>, and, just like ., it's a stand-in anyway. Towards the beginning of my PhD, I spent some time inventing rewrite rules to operate on pairs of operators taken from a defined, known set. I began representing the rules much as in the example above. Later on, I wanted to encode them as real Haskell, in order to check them more thoroughly. The above rule, I first encoded like this

filterFilterPre     = streamFilter g . streamFilter f
filterFilterPost    = streamFilter (g . f)
prop_filterFilter s = filterFilterPre s == filterFilterPost s

This is real code: the operators were already implemented in StrIoT, and the final expression defined a property for QuickCheck. However, it's still not quite a rewrite rule. The left-hand side, which should be a pattern, is really a concrete expression. The names f and g are masquerading as free variables but are really concretely defined in a preamble I wrote to support running QuickCheck against these things: usually simple stuff like g = odd, etc. Eventually, I had to figure out how to really implement rewrite rules in StrIoT. There were a few approaches I could take. One would be to express the rules in some abstract form like the first example (but with properly defined semantics) and write a parser for them: I really wanted to avoid doing that. As a happy accident, the solution I landed on was enabled by the semantics of algebraic-graphs, a Graph library we adopted to support representing a stream-processing topology. I wrote more about that in data-types for representing stream-processing programs. I was able to implement rewrite rules as ordinary Haskell functions. The left-hand side of the rewrite rule maps to the left-hand side (pattern) part of a function definition. The function body implements the right-hand side. The system that applies the rules attempts to apply each rewrite rule to every sub-graph of a stream-processing program. The rewrite functions therefore need to signal whether or not they're applicable at runtime. For that reason, the return type is wrapped in Maybe, and we provide a catch-all pattern for every rule which simply returns Nothing. The right-hand side implementation can be pretty thorny. On the left-hand side, the stream operator connector we've finally ended up with is Connect from algebraic-graphs. Here's filter fuse, taken from the full ruleset:

filterFuse :: RewriteRule
filterFuse (Connect (Vertex a@(StreamVertex i (Filter sel1) (p:_) ty _ s1))
                    (Vertex b@(StreamVertex _ (Filter sel2) (q:_) _ _ s2))) =
    let c = a   operator    = Filter (sel1 * sel2)
              , parameters  = [\[  (\p q x -> p x && q x) $(p) $(q)  ]]
              , serviceTime = sumTimes s1 sel1 s2
               
    in Just (removeEdge c c . mergeVertices ( elem  [a,b]) c)
filterFuse _ = Nothing

That's perhaps the simplest rule in the set. (See e.g. hoistOp for one of the worst!) The question that remains to me, is, which representation, or representations, to use in the thesis? I'm currently planning to skip the abstract example I started with and start with the concrete Haskell encoding using QuickCheck. I'm not sure if it seems weird to have two completely separate implementations of the rules, but the simpler QuickCheck-checked rules are much closer to the "core essence" of the rules than the final implementation in StrIoT. And the derivation of the rules comes earlier in the timeline than the design work that led to the final StrIoT implementation. The middle-option is still compromised, however, by having concrete expressions pretending to be patterns. So I'm not sure.

Today I released mrcal 2.2 (the release notes are available here). This release contains lots of medium-important internal improvements, and is a result of

• Heavy dogfooding. I use these tools a lot every day, and many things are nicer, easier and work better in 2.2 than in 2.1
• Not-yet-completed cool new functionality. Some of the required internal improvements for the big new features are being released here.

The biggest single new feature in this release is the interactive graphical tool for examining dense stereo results: accessed via mrcal-stereo --viz stereo. The next pressing thing is improved documentation. The tour of mrcal is still a good overview of some of the functionality that makes mrcal unique and far better than traditional calibration tools. But it doesn't do a good job of demonstrating how you would actually use mrcal to diagnose and handle common calibration issues. I need to gather some releasable representative data, and write docs around that. Then I'm going to start finishing the big new features in the roadmap (these are all already functional, but need polish):

• Triangulation functions in the optimization loop for efficient structure-from-motion
• Support for non-central projection to remove a significant source of bias present in very wide lenses
• Improved projection uncertainty quantification to resolve accuracy and performance issues in the current projection uncertainty method

Death Certificate After waiting for almost two, two, and a half months, I finally got mum s death certificate last week. A part of me was saddened as it felt like I was nailing her or putting nails to the coffin or whatever it is, (even though I m an Agarwal) I just felt sad and awful. I was told just get a death certificate and your problems will be over. Some people wanted me to give some amount under the table or something which I didn t want to party of and because of that perhaps it took a month, month and a half more as I came to know later that it had been issued almost a month and a half back. The inflation over the last 8 years of the present Govt. has made the corrupt even more corrupt, all the while projecting and telling others that the others are corrupt. There had been also a few politicians who were caught red-handed but then pieces of evidence & witnesses vanish overnight. I don t really wanna go in that direction as it would make for an unpleasant reading with no solutions at all unless the present Central Govt. goes out.

Intestate and Will I came to know the word Intestate. This was a new word/term for me. A lookup told me that intestate means a person dying without putting a will. That legal term comes from U.K. law. I had read a long long time back that almost all our laws have and were made or taken from U.K. law. IIRC, massive sections of the CRPC Act even today have that colonial legacy. While in its (BJP) manifesto that had been shared with the public at the time of the election, they had shared that they will remove a whole swathe of laws that don t make sense in today s environment. But when hard and good questions were asked, they trimmed a few, modified a few, and left most of them as it is. Sadly, most of the laws that they did modify increased Government control over people instead of decreasing, It s been 8 years and yet we still don t have a Privacy law. They had made something but it was too vague and would have invited suits from day 1 so pretty much on backburner :(. A good insight into what I mean is an article in the Hindu I read a few days back. Once you read that article, I am sure you will have as many questions as I have but sadly no answers. Law is not supposed to be partisan but today it is. I could cite examples from both the U.S. and UK courts about progressive judgments or the way they go about it, but then again when our people think they know better But this again does not help me apart from setting some kind of background of where we are.) I have on this blog also shared how Africans have been setting new records in transparency and they did it almost 5 years back. For those new to the blog, African countries have been now broadcasting proceedings of their SC for almost 5 years now. I noticed it when privacy law was being debated and a few handles that I follow on Twitter and elsewhere had gone and given their submission in their SC. It was fascinating to not only hear but also read about the case from multiple viewpoints. And just to remind people, I am sharing all of this from Pune, Maharashtra which is the second-biggest city in Maharashtra that has something like six million people and probably a million or more transitory students, and casual laborers but then again that doesn t help me other than providing a kind of context to what I m sharing.. Now a couple of years back or more I had asked mum to make a will. If she wanted to bequeath something to somebody else she could do that, had shared about that. There was some article in Indian Express or elsewhere that told people what they should be doing, especially if they had cost the barrier of age 60. Now for reasons best known to her, she refused and now I have to figure out what is the right way to go about doing things.

Twitter Experiences Now before Twitter, a few people had been asking me about having a legal heir certificate, while others are asking about a succession certificate and some claim a Death Certificate is enough. Now I asked the same question on Twitter hoping at the max of 5-10 responses but was overwhelmed by the response. I got something like 50-60 odd replies. Probably, one of the better responses was given by Dr. Paras Jain who shared the following

Answer is qualified Movable assets nothing required Bank LIC flat with society nomination done nothing required except death certificate. However, each will insist on a notarized indemnity bond If the nomination is not done. Depends on whims & fancy of each mind legal heir certificate,+ all Dr. Paras Jain. (cleared up the grammar a little, otherwise, views are of Dr. Paras.) What was interesting for me is that most people just didn t give me advice, many of them also shared their own experiences or what they did or went through. I was surprised to learn e.g. that a succession certificate can take up to 6 months or more. Part of me isn t surprised to learn that as do know we have a huge pendency of cases in High Courts, District Courts leading all the way to the Supreme Court. India Today shared a brief article sharing the same and similar issues. Such delays have become far too common now

Supertech Demolition and Others Over the last couple of months, a number of high-profile demolitions have taken place and in most cases, the loss has been of homebuyers. See for e.g. the case of Supertech. A much more detailed article was penned by Moneylife. There were a few Muslims whose homes were demolished just a couple of months back that were being celebrated, but now just 2-3 days back a politician by the name of Shrikant Tyagi, a BJP leader, his flat was partly demolished and there was a lot of hue and cry. Although we shouldn t be discussing on the basis of religion but legality, somehow the idea has been put that there are two kinds of laws, one for the majority, the other for the minority. And this has been going on for the last 8 odd years, hence you see different reactions to the same incidents instead of similar reactions. In all the cases, no strictures are passed either against the Municipality or against lenders. The most obvious question, let s say for argument s sake, I was a homeowner in Supertech. I bought a flat for say 10 lakhs in 2012. According to the courts, today I am supposed to get 22 lakhs at 12% simple interest for 10 years. Let s say even if the builder was in a position and does honor the order, the homeowner will not get a house in the same area as the circle rate would probably have quadrupled by then at the very least. The circle rate alone might be the above amount. The reason is very simple, a builder buys land on the cheap when there is no development around. His/her/their whole idea is once development happens due to other builders also building flats, the whole area gets developed and they are able to sell the flats at a premium. Even Circle rates get affected as the builder pays below the table and asks the officers of the municipal authority to hike the circle rate every few months. Again, wouldn t go into much depth as the whole thing is rotten to the core. There are many such projects. I have shared Krishnaraj Rao s videos on this blog a few times. I am sure there are a few good men like him. At the end, sadly this is where we are P.S. I haven t shared any book reviews this week as this post itself has become too long. I probably may blog about a couple of books in the next couple of days, till later.

Focus This month I didn't have any particular focus. I just worked on issues in my info bubble.

Changes

• halibut: add documentation generator metadata
• mpv-mpris: fix tests
• duck: obsolete site indicators
• devscripts: fix example, add experimental pseudo-excuses
• dpkg-repack: show dpkg-deb cmd
• Debian QA services: add experimental pseudo-excuses, improve excuses page
• Debian usertags: fixed ports, lintian usertags
• Debian package uploads: mpv-mpris backport
• Debian wiki pages: ArchitectureSpecificsMemo, DebianArt/Themes/Emerald, DebianDesktop/Artwork (Bookworm), DebianLogo, DeveloperNews, FPGA, Gnome, HomeAssistant, InstructionSelection (1 2), LTS, PackageKit, PipeWire, Salsa/support, Services, ServicesHosting, SIMDEverywhere, SimpleBackportCreation, spotify, SystemBuildTools, ThomasChung, UsingSymbolsFiles, ZRam, Zswap
• Libreplanet wiki pages: Group:Free_Software_Foundation/Ideas
• FOSSjobs wiki pages: Resources
• Wikipedia: Message-ID

Issues

• Conffile removal in dkms
• Features in UDD, virtual-fido
• Security hardening in open-in-mpv
• Packaging needed for prr, libredirect, wayback-machine-webextension
• Underlinking in libgrpc
• Data import problem in UDD
• HTML injection in a conversion utility (sent privately)

Review

• Debian wiki: RecentChanges for the month
• Debian BTS usertags: changes for the month
• Debian screenshots:
  • approved apticron-systemd argyll chromium-browser coreutils e2fsprogs exuberant-ctags firefox gnome-flashback gnome-recipes gparted initramfs-tools kdocker kleopatra latte-dock mac-robber mail-expire mgba-qt mount parolottero-data-us plasma-widget-folderview reglookup stockfish sxmo-utils uuid-runtime yoshimi
  • rejected weboob-qt/quake (politics), pass (baby photo), hylafax-client/libc6/ (photo of broken screen), aptitude (screenshots website), apt-file (NSFW photo), synaesthesia (meme image), kde-full (photo of human), ubuntustudio-menu (too small), tesseract-ocr-eng (identification card), mpv (proprietary video), g++-9/python3-ldap (random logo), synaptic (logo), openjdk-8-jre (NSFW, mobile browser), libreoffice-base-core/librtmp1/audacity (Android/iOS app), virtualbox-guest-additions-iso (ISO contents not interface), weboob-qt (another package), freecell-solver-bin (accidentally)

Administration

• Debian QA services: deploy changes
• Debian wiki: approve accounts

Communication

• Respond to queries from Debian users and contributors on the mailing lists and IRC

Sponsors All work was done on a volunteer basis.

Well this is a mouthful. I recently worked on a neat hack called puppet-package-check. It is designed to warn about manually installed packages, to make sure "everything is in Puppet". But it turns out it can (probably?) dramatically decrease the bootstrap time of Puppet bootstrap when it needs to install a large number of packages.

Detecting manual packages On a cleanly filed workstation, it looks like this:

root@emma:/home/anarcat/bin# ./puppet-package-check -v
listing puppet packages...
listing apt packages...
loading apt cache...
0 unmanaged packages found

A messy workstation will look like this:

root@curie:/home/anarcat/bin# ./puppet-package-check -v
listing puppet packages...
listing apt packages...
loading apt cache...
288 unmanaged packages found
apparmor-utils beignet-opencl-icd bridge-utils clustershell cups-pk-helper davfs2 dconf-cli dconf-editor dconf-gsettings-backend ddccontrol ddrescueview debmake debootstrap decopy dict-devil dict-freedict-eng-fra dict-freedict-eng-spa dict-freedict-fra-eng dict-freedict-spa-eng diffoscope dnsdiag dropbear-initramfs ebtables efibootmgr elpa-lua-mode entr eog evince figlet file file-roller fio flac flex font-manager fonts-cantarell fonts-inconsolata fonts-ipafont-gothic fonts-ipafont-mincho fonts-liberation fonts-monoid fonts-monoid-tight fonts-noto fonts-powerline fonts-symbola freeipmi freetype2-demos ftp fwupd-amd64-signed gallery-dl gcc-arm-linux-gnueabihf gcolor3 gcp gdisk gdm3 gdu gedit gedit-plugins gettext-base git-debrebase gnome-boxes gnote gnupg2 golang-any golang-docker-credential-helpers golang-golang-x-tools grub-efi-amd64-signed gsettings-desktop-schemas gsfonts gstreamer1.0-libav gstreamer1.0-plugins-base gstreamer1.0-plugins-good gstreamer1.0-plugins-ugly gstreamer1.0-pulseaudio gtypist gvfs-backends hackrf hashcat html2text httpie httping hugo humanfriendly iamerican-huge ibus ibus-gtk3 ibus-libpinyin ibus-pinyin im-config imediff img2pdf imv initramfs-tools input-utils installation-birthday internetarchive ipmitool iptables iptraf-ng jackd2 jupyter jupyter-nbextension-jupyter-js-widgets jupyter-qtconsole k3b kbtin kdialog keditbookmarks keepassxc kexec-tools keyboard-configuration kfind konsole krb5-locales kwin-x11 leiningen lightdm lintian linux-image-amd64 linux-perf lmodern lsb-base lvm2 lynx lz4json magic-wormhole mailscripts mailutils manuskript mat2 mate-notification-daemon mate-themes mime-support mktorrent mp3splt mpdris2 msitools mtp-tools mtree-netbsd mupdf nautilus nautilus-sendto ncal nd ndisc6 neomutt net-tools nethogs nghttp2-client nocache npm2deb ntfs-3g ntpdate nvme-cli nwipe obs-studio okular-extra-backends openstack-clients openstack-pkg-tools paprefs pass-extension-audit pcmanfm pdf-presenter-console pdf2svg percol pipenv playerctl plymouth plymouth-themes popularity-contest progress prometheus-node-exporter psensor pubpaste pulseaudio python3-ldap qjackctl qpdfview qrencode r-cran-ggplot2 r-cran-reshape2 rake restic rhash rpl rpm2cpio rs ruby ruby-dev ruby-feedparser ruby-magic ruby-mocha ruby-ronn rygel-playbin rygel-tracker s-tui sanoid saytime scrcpy scrcpy-server screenfetch scrot sdate sddm seahorse shim-signed sigil smartmontools smem smplayer sng sound-juicer sound-theme-freedesktop spectre-meltdown-checker sq ssh-audit sshuttle stress-ng strongswan strongswan-swanctl syncthing system-config-printer system-config-printer-common system-config-printer-udev systemd-bootchart systemd-container tardiff task-desktop task-english task-ssh-server tasksel tellico texinfo texlive-fonts-extra texlive-lang-cyrillic texlive-lang-french texlive-lang-german texlive-lang-italian texlive-xetex tftp-hpa thunar-archive-plugin tidy tikzit tint2 tintin++ tipa tpm2-tools traceroute tree trocla ucf udisks2 unifont unrar-free upower usbguard uuid-runtime vagrant-cachier vagrant-libvirt virt-manager vmtouch vorbis-tools w3m wamerican wamerican-huge wfrench whipper whohas wireshark xapian-tools xclip xdg-user-dirs-gtk xlax xmlto xsensors xserver-xorg xsltproc xxd xz-utils yubioath-desktop zathura zathura-pdf-poppler zenity zfs-dkms zfs-initramfs zfsutils-linux zip zlib1g zlib1g-dev
157 old: apparmor-utils clustershell davfs2 dconf-cli dconf-editor ddccontrol ddrescueview decopy dnsdiag ebtables efibootmgr elpa-lua-mode entr figlet file-roller fio flac flex font-manager freetype2-demos ftp gallery-dl gcc-arm-linux-gnueabihf gcolor3 gcp gdu gedit git-debrebase gnote golang-docker-credential-helpers golang-golang-x-tools gtypist hackrf hashcat html2text httpie httping hugo humanfriendly iamerican-huge ibus ibus-pinyin imediff input-utils internetarchive ipmitool iptraf-ng jackd2 jupyter-qtconsole k3b kbtin kdialog keditbookmarks keepassxc kexec-tools kfind konsole leiningen lightdm lynx lz4json magic-wormhole manuskript mat2 mate-notification-daemon mktorrent mp3splt msitools mtp-tools mtree-netbsd nautilus nautilus-sendto nd ndisc6 neomutt net-tools nethogs nghttp2-client nocache ntpdate nwipe obs-studio openstack-pkg-tools paprefs pass-extension-audit pcmanfm pdf-presenter-console pdf2svg percol pipenv playerctl qjackctl qpdfview qrencode r-cran-ggplot2 r-cran-reshape2 rake restic rhash rpl rpm2cpio rs ruby-feedparser ruby-magic ruby-mocha ruby-ronn s-tui saytime scrcpy screenfetch scrot sdate seahorse shim-signed sigil smem smplayer sng sound-juicer spectre-meltdown-checker sq ssh-audit sshuttle stress-ng system-config-printer system-config-printer-common tardiff tasksel tellico texlive-lang-cyrillic texlive-lang-french tftp-hpa tikzit tint2 tintin++ tpm2-tools traceroute tree unrar-free vagrant-cachier vagrant-libvirt vmtouch vorbis-tools w3m wamerican wamerican-huge wfrench whipper whohas xdg-user-dirs-gtk xlax xmlto xsensors xxd yubioath-desktop zenity zip
131 new: beignet-opencl-icd bridge-utils cups-pk-helper dconf-gsettings-backend debmake debootstrap dict-devil dict-freedict-eng-fra dict-freedict-eng-spa dict-freedict-fra-eng dict-freedict-spa-eng diffoscope dropbear-initramfs eog evince file fonts-cantarell fonts-inconsolata fonts-ipafont-gothic fonts-ipafont-mincho fonts-liberation fonts-monoid fonts-monoid-tight fonts-noto fonts-powerline fonts-symbola freeipmi fwupd-amd64-signed gdisk gdm3 gedit-plugins gettext-base gnome-boxes gnupg2 golang-any grub-efi-amd64-signed gsettings-desktop-schemas gsfonts gstreamer1.0-libav gstreamer1.0-plugins-base gstreamer1.0-plugins-good gstreamer1.0-plugins-ugly gstreamer1.0-pulseaudio gvfs-backends ibus-gtk3 ibus-libpinyin im-config img2pdf imv initramfs-tools installation-birthday iptables jupyter jupyter-nbextension-jupyter-js-widgets keyboard-configuration krb5-locales kwin-x11 lintian linux-image-amd64 linux-perf lmodern lsb-base lvm2 mailscripts mailutils mate-themes mime-support mpdris2 mupdf ncal npm2deb ntfs-3g nvme-cli okular-extra-backends openstack-clients plymouth plymouth-themes popularity-contest progress prometheus-node-exporter psensor pubpaste pulseaudio python3-ldap ruby ruby-dev rygel-playbin rygel-tracker sanoid scrcpy-server sddm smartmontools sound-theme-freedesktop strongswan strongswan-swanctl syncthing system-config-printer-udev systemd-bootchart systemd-container task-desktop task-english task-ssh-server texinfo texlive-fonts-extra texlive-lang-german texlive-lang-italian texlive-xetex thunar-archive-plugin tidy tipa trocla ucf udisks2 unifont upower usbguard uuid-runtime virt-manager wireshark xapian-tools xclip xserver-xorg xsltproc xz-utils zathura zathura-pdf-poppler zfs-dkms zfs-initramfs zfsutils-linux zlib1g zlib1g-dev

Yuck! That's a lot of shit to go through. Notice how the packages get sorted between "old" and "new" packages. This is because popcon is used as a tool to mark which packages are "old". If you have unmanaged packages, the "old" ones are likely things that you can uninstall, for example. If you don't have popcon installed, you'll also get this warning:

popcon stats not available: [Errno 2] No such file or directory: '/var/log/popularity-contest'

The error can otherwise be safely ignored, but you won't get "help" prioritizing the packages to add to your manifests. Note that the tool ignores packages that were "marked" (see apt-mark(8)) as automatically installed. This implies that you might have to do a little bit of cleanup the first time you run this, as Debian doesn't necessarily mark all of those packages correctly on first install. For example, here's how it looks like on a clean install, after Puppet ran:

root@angela:/home/anarcat# ./bin/puppet-package-check -v
listing puppet packages...
listing apt packages...
loading apt cache...
127 unmanaged packages found
ca-certificates console-setup cryptsetup-initramfs dbus file gcc-12-base gettext-base grub-common grub-efi-amd64 i3lock initramfs-tools iw keyboard-configuration krb5-locales laptop-detect libacl1 libapparmor1 libapt-pkg6.0 libargon2-1 libattr1 libaudit-common libaudit1 libblkid1 libbpf0 libbsd0 libbz2-1.0 libc6 libcap-ng0 libcap2 libcap2-bin libcom-err2 libcrypt1 libcryptsetup12 libdb5.3 libdebconfclient0 libdevmapper1.02.1 libedit2 libelf1 libext2fs2 libfdisk1 libffi8 libgcc-s1 libgcrypt20 libgmp10 libgnutls30 libgpg-error0 libgssapi-krb5-2 libhogweed6 libidn2-0 libip4tc2 libiw30 libjansson4 libjson-c5 libk5crypto3 libkeyutils1 libkmod2 libkrb5-3 libkrb5support0 liblocale-gettext-perl liblockfile-bin liblz4-1 liblzma5 libmd0 libmnl0 libmount1 libncurses6 libncursesw6 libnettle8 libnewt0.52 libnftables1 libnftnl11 libnl-3-200 libnl-genl-3-200 libnl-route-3-200 libnss-systemd libp11-kit0 libpam-systemd libpam0g libpcre2-8-0 libpcre3 libpcsclite1 libpopt0 libprocps8 libreadline8 libselinux1 libsemanage-common libsemanage2 libsepol2 libslang2 libsmartcols1 libss2 libssl1.1 libssl3 libstdc++6 libsystemd-shared libsystemd0 libtasn1-6 libtext-charwidth-perl libtext-iconv-perl libtext-wrapi18n-perl libtinfo6 libtirpc-common libtirpc3 libudev1 libunistring2 libuuid1 libxtables12 libxxhash0 libzstd1 linux-image-amd64 logsave lsb-base lvm2 media-types mlocate ncurses-term pass-extension-otp puppet python3-reportbug shim-signed tasksel ucf usr-is-merged util-linux-extra wpasupplicant xorg zlib1g
popcon stats not available: [Errno 2] No such file or directory: '/var/log/popularity-contest'

Normally, there should be unmanaged packages here. But because of the way Debian is installed, a lot of libraries and some core packages are marked as manually installed, and are of course not managed through Puppet. There are two solutions to this problem:

• really manage everything in Puppet (argh)
• mark packages as automatically installed

I typically chose the second path and mark a ton of stuff as automatic. Then either they will be auto-removed, or will stop being listed. In the above scenario, one could mark all libraries as automatically installed with:

apt-mark auto $(./bin/puppet-package-check   grep -o 'lib[^ ]*')

... but if you trust that most of that stuff is actually garbage that you don't really want installed anyways, you could just mark it all as automatically installed:

apt-mark auto $(./bin/puppet-package-check)

In my case, that ended up keeping basically all libraries (because of course they're installed for some reason) and auto-removing this:

dh-dkms discover-data dkms libdiscover2 libjsoncpp25 libssl1.1 linux-headers-amd64 mlocate pass-extension-otp pass-otp plocate x11-apps x11-session-utils xinit xorg

You'll notice xorg in there: yep, that's bad. Not what I wanted. But for some reason, on other workstations, I did not actually have xorg installed. Turns out having xserver-xorg is enough, and that one has dependencies. So now I guess I just learned to stop worrying and live without X(org).

Optimizing large package installs But that, of course, is not all. Why make things simple when you can have an unreadable title that is trying to be both syntactically correct and click-baity enough to flatter my vain ego? Right. One of the challenges in bootstrapping Puppet with large package lists is that it's slow. Puppet lists packages as individual resources and will basically run apt install $PKG on every package in the manifest, one at a time. While the overhead of apt is generally small, when you add things like apt-listbugs, apt-listchanges, needrestart, triggers and so on, it can take forever setting up a new host. So for initial installs, it can actually makes sense to skip the queue and just install everything in one big batch. And because the above tool inspects the packages installed by Puppet, you can run it against a catalog and have a full lists of all the packages Puppet would install, even before I even had Puppet running. So when reinstalling my laptop, I basically did this:

apt install puppet-agent/experimental
puppet agent --test --noop
apt install $(./puppet-package-check --debug \
    2>&1   grep ^puppet\ packages 
      sed 's/puppet packages://;s/ /\n/g'
      grep -v -e onionshare -e golint -e git-sizer -e github-backup -e hledger -e xsane -e audacity -e chirp -e elpa-flycheck -e elpa-lsp-ui -e yubikey-manager -e git-annex -e hopenpgp-tools -e puppet
) puppet-agent/experimental

That massive grep was because there are currently a lot of packages missing from bookworm. Those are all packages that I have in my catalog but that still haven't made it to bookworm. Sad, I know. I eventually worked around that by adding bullseye sources so that the Puppet manifest actually ran. The point here is that this improves the Puppet run time a lot. All packages get installed at once, and you get a nice progress bar. Then you actually run Puppet to deploy configurations and all the other goodies:

puppet agent --test

I wish I could tell you how much faster that ran. I don't know, and I will not go through a full reinstall just to please your curiosity. The only hard number I have is that it installed 444 packages (which exploded in 10,191 packages with dependencies) in a mere 10 minutes. That might also be with the packages already downloaded. In any case, I have that gut feeling it's faster, so you'll have to just trust my gut. It is, after all, much more important than you might think.

Similar work The blueprint system is something similar to this:

It figures out what you ve done manually, stores it locally in a Git repository, generates code that s able to recreate your efforts, and helps you deploy those changes to production

That tool has unfortunately been abandoned for a decade at this point. Also note that the AutoRemove::RecommendsImportant and AutoRemove::SuggestsImportant are relevant here. If it is set to true (the default), a package will not be removed if it is (respectively) a Recommends or Suggests of another package (as opposed to the normal Depends). In other words, if you want to also auto-remove packages that are only Suggests, you would, for example, add this to apt.conf:

AutoRemove::SuggestsImportant false;

Paul Wise has tried to make the Debian installer and debootstrap properly mark packages as automatically installed in the past, but his bug reports were rejected. The other suggestions in this section are also from Paul, thanks!

After upgrading to Ubuntu Jammy and Asterisk 18.10, I saw the following messages in my logs:

WARNING[360166]: loader.c:2487 in load_modules: Module 'chan_sip' has been loaded but was deprecated in Asterisk version 17 and will be removed in Asterisk version 21.
WARNING[360174]: chan_sip.c:35468 in deprecation_notice: chan_sip has no official maintainer and is deprecated.  Migration to
WARNING[360174]: chan_sip.c:35469 in deprecation_notice: chan_pjsip is recommended.  See guides at the Asterisk Wiki:
WARNING[360174]: chan_sip.c:35470 in deprecation_notice: https://wiki.asterisk.org/wiki/display/AST/Migrating+from+chan_sip+to+res_pjsip
WARNING[360174]: chan_sip.c:35471 in deprecation_notice: https://wiki.asterisk.org/wiki/display/AST/Configuring+res_pjsip

and so I decided it was time to stop postponing the overdue migration of my working setup from chan_sip to res_pjsip. It turns out that it was not as painful as I expected, though the conversion script bundled with Asterisk didn't work for me out of the box.

Debugging Before you start, one very important thing to note is that the SIP debug information you used to see when running this in the asterisk console (asterisk -r):

sip set debug on

now lives behind this command:

pjsip set logger on

SIP phones The first thing I migrated was the config for my two SIP phones (Snom 300 and Snom D715). The original config for them in sip.conf was:

[2000]
; Snom 300
type=friend
qualify=yes
secret=password123
encryption=no
context=full
host=dynamic
nat=no
directmedia=no
mailbox=10@internal
vmexten=707
dtmfmode=rfc2833
call-limit=2
disallow=all
allow=g722
allow=ulaw
[2001]
; Snom D715
type=friend
qualify=yes
secret=password456
encryption=no
context=full
host=dynamic
nat=no
directmedia=yes
mailbox=10@internal
vmexten=707
dtmfmode=rfc2833
call-limit=2
disallow=all
allow=g722
allow=ulaw

and that became the following in pjsip.conf:

[transport-udp]
type = transport
protocol = udp
bind = 0.0.0.0
external_media_address = myasterisk.dyn.example.com
external_signaling_address = myasterisk.dyn.example.com
local_net = 192.168.0.0/255.255.0.0
[2000]
type = aor
max_contacts = 1
[2000]
type = auth
username = 2000
password = password123
[2000]
type = endpoint
context = full
dtmf_mode = rfc4733
disallow = all
allow = g722
allow = ulaw
direct_media = no
mailboxes = 10@internal
auth = 2000
outbound_auth = 2000
aors = 2000
[2001]
type = aor
max_contacts = 1
[2001]
type = auth
username = 2001
password = password456
[2001]
type = endpoint
context = full
dtmf_mode = rfc4733
disallow = all
allow = g722
allow = ulaw
direct_media = yes
mailboxes = 10@internal
auth = 2001
outbound_auth = 2001
aors = 2001

The different direct_media line between the two phones has to do with how they each connect to my Asterisk server and whether or not they have access to the Internet.

Internal calls For some reason, my internal calls (from one SIP phone to the other) didn't work when using "aliases". I fixed it by changing this blurb in extensions.conf from:

[speeddial]
exten => 1000,1,Dial(SIP/2000,20)
exten => 1001,1,Dial(SIP/2001,20)

to:

[speeddial]
exten => 1000,1,Dial($ PJSIP_DIAL_CONTACTS(2000) ,20)
exten => 1001,1,Dial($ PJSIP_DIAL_CONTACTS(2001) ,20)

I have not yet dug into what this changes or why it's necessary and so feel free to leave a comment if you know more here.

PSTN trunk Once I had the internal phones working, I moved to making and receiving phone calls over the PSTN, for which I use VoIP.ms with encryption. I had to change the following in my sip.conf:

[general]
register => tls://555123_myasterisk:password789@vancouver2.voip.ms
externhost=myasterisk.dyn.example.com
localnet=192.168.0.0/255.255.0.0
tcpenable=yes
tlsenable=yes
tlscertfile=/etc/asterisk/asterisk.cert
tlsprivatekey=/etc/asterisk/asterisk.key
tlscapath=/etc/ssl/certs/
[voipms]
type=peer
host=vancouver2.voip.ms
secret=password789
defaultuser=555123_myasterisk
context=from-voipms
disallow=all
allow=ulaw
allow=g729
insecure=port,invite
canreinvite=no
trustrpid=yes
sendrpid=yes
transport=tls
encryption=yes

to the following in pjsip.conf:

[transport-tls]
type = transport
protocol = tls
bind = 0.0.0.0
external_media_address = myasterisk.dyn.example.com
external_signaling_address = myasterisk.dyn.example.com
local_net = 192.168.0.0/255.255.0.0
cert_file = /etc/asterisk/asterisk.cert
priv_key_file = /etc/asterisk/asterisk.key
ca_list_path = /etc/ssl/certs/
method = tlsv1_2
[voipms]
type = registration
transport = transport-tls
outbound_auth = voipms
client_uri = sip:555123_myasterisk@vancouver2.voip.ms
server_uri = sip:vancouver2.voip.ms
[voipms]
type = auth
password = password789
username = 555123_myasterisk
[voipms]
type = aor
contact = sip:555123_myasterisk@vancouver2.voip.ms
[voipms]
type = identify
endpoint = voipms
match = vancouver2.voip.ms
[voipms]
type = endpoint
context = from-voipms
disallow = all
allow = ulaw
allow = g729
from_user = 555123_myasterisk
trust_id_inbound = yes
media_encryption = sdes
auth = voipms
outbound_auth = voipms
aors = voipms
rtp_symmetric = yes
rewrite_contact = yes
send_rpid = yes
timers = no

The TLS method line is needed since the default in Debian OpenSSL is too strict. The timers line is to prevent outbound calls from getting dropped after 15 minutes. Finally, I changed the Dial() lines in these extensions.conf blurbs from:

[from-voipms]
exten => 5551231000,1,Goto(2000,1)
exten => 2000,1,Dial(SIP/2000&SIP/2001,20)
exten => 2000,n,Goto(in2000-$ DIALSTATUS ,1)
exten => 2000,n,Hangup
exten => in2000-BUSY,1,VoiceMail(10@internal,su)
exten => in2000-BUSY,n,Hangup
exten => in2000-CONGESTION,1,VoiceMail(10@internal,su)
exten => in2000-CONGESTION,n,Hangup
exten => in2000-CHANUNAVAIL,1,VoiceMail(10@internal,su)
exten => in2000-CHANUNAVAIL,n,Hangup
exten => in2000-NOANSWER,1,VoiceMail(10@internal,su)
exten => in2000-NOANSWER,n,Hangup
exten => _in2000-.,1,Hangup(16)
[pstn-voipms]
exten => _1NXXNXXXXXX,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _1NXXNXXXXXX,n,Dial(SIP/voipms/$ EXTEN )
exten => _1NXXNXXXXXX,n,Hangup()
exten => _NXXNXXXXXX,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _NXXNXXXXXX,n,Dial(SIP/voipms/1$ EXTEN )
exten => _NXXNXXXXXX,n,Hangup()
exten => _011X.,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _011X.,n,Authenticate(1234)
exten => _011X.,n,Dial(SIP/voipms/$ EXTEN )
exten => _011X.,n,Hangup()
exten => _00X.,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _00X.,n,Authenticate(1234)
exten => _00X.,n,Dial(SIP/voipms/$ EXTEN )
exten => _00X.,n,Hangup()

to:

[from-voipms]
exten => 5551231000,1,Goto(2000,1)
exten => 2000,1,Dial(PJSIP/2000&PJSIP/2001,20)
exten => 2000,n,Goto(in2000-$ DIALSTATUS ,1)
exten => 2000,n,Hangup
exten => in2000-BUSY,1,VoiceMail(10@internal,su)
exten => in2000-BUSY,n,Hangup
exten => in2000-CONGESTION,1,VoiceMail(10@internal,su)
exten => in2000-CONGESTION,n,Hangup
exten => in2000-CHANUNAVAIL,1,VoiceMail(10@internal,su)
exten => in2000-CHANUNAVAIL,n,Hangup
exten => in2000-NOANSWER,1,VoiceMail(10@internal,su)
exten => in2000-NOANSWER,n,Hangup
exten => _in2000-.,1,Hangup(16)
[pstn-voipms]
exten => _1NXXNXXXXXX,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _1NXXNXXXXXX,n,Dial(PJSIP/$ EXTEN @voipms)
exten => _1NXXNXXXXXX,n,Hangup()
exten => _NXXNXXXXXX,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _NXXNXXXXXX,n,Dial(PJSIP/1$ EXTEN @voipms)
exten => _NXXNXXXXXX,n,Hangup()
exten => _011X.,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _011X.,n,Authenticate(1234)
exten => _011X.,n,Dial(PJSIP/$ EXTEN @voipms)
exten => _011X.,n,Hangup()
exten => _00X.,1,Set(CALLERID(all)=Francois Marier <5551231000>)
exten => _00X.,n,Authenticate(1234)
exten => _00X.,n,Dial(PJSIP/$ EXTEN @voipms)
exten => _00X.,n,Hangup()

Note that it's not just replacing SIP/ with PJSIP/, but it was also necessary to use a format supported by pjsip for the channel since SIP/trunkname/extension isn't supported by pjsip.

This post describes how I ve put together a simple static content server for kubernetes clusters using a Pod with a persistent volume and multiple containers: an sftp server to manage contents, a web server to publish them with optional access control and another one to run scripts which need access to the volume filesystem. The sftp server runs using MySecureShell, the web server is nginx and the script runner uses the webhook tool to publish endpoints to call them (the calls will come from other Pods that run backend servers or are executed from Jobs or CronJobs).

HistoryThe system was developed because we had a NodeJS API with endpoints to upload files and store them on S3 compatible services that were later accessed via HTTPS, but the requirements changed and we needed to be able to publish folders instead of individual files using their original names and apply access restrictions using our API. Thinking about our requirements the use of a regular filesystem to keep the files and folders was a good option, as uploading and serving files is simple. For the upload I decided to use the sftp protocol, mainly because I already had an sftp container image based on mysecureshell prepared; once we settled on that we added sftp support to the API server and configured it to upload the files to our server instead of using S3 buckets. To publish the files we added a nginx container configured to work as a reverse proxy that uses the ngx_http_auth_request_module to validate access to the files (the sub request is configurable, in our deployment we have configured it to call our API to check if the user can access a given URL). Finally we added a third container when we needed to execute some tasks directly on the filesystem (using kubectl exec with the existing containers did not seem a good idea, as that is not supported by CronJobs objects, for example). The solution we found avoiding the NIH Syndrome (i.e. write our own tool) was to use the webhook tool to provide the endpoints to call the scripts; for now we have three:

• one to get the disc usage of a PATH,
• one to hardlink all the files that are identical on the filesystem,
• one to copy files and folders from S3 buckets to our filesystem.

Container definitions

mysecureshellThe mysecureshell container can be used to provide an sftp service with multiple users (although the files are owned by the same UID and GID) using standalone containers (launched with docker or podman) or in an orchestration system like kubernetes, as we are going to do here. The image is generated using the following Dockerfile:

ARG ALPINE_VERSION=3.16.2
FROM alpine:$ALPINE_VERSION as builder
LABEL maintainer="Sergio Talens-Oliag <sto@mixinet.net>"
RUN apk update &&\
 apk add --no-cache alpine-sdk git musl-dev &&\
 git clone https://github.com/sto/mysecureshell.git &&\
 cd mysecureshell &&\
 ./configure --prefix=/usr --sysconfdir=/etc --mandir=/usr/share/man\
 --localstatedir=/var --with-shutfile=/var/lib/misc/sftp.shut --with-debug=2 &&\
 make all && make install &&\
 rm -rf /var/cache/apk/*
FROM alpine:$ALPINE_VERSION
LABEL maintainer="Sergio Talens-Oliag <sto@mixinet.net>"
COPY --from=builder /usr/bin/mysecureshell /usr/bin/mysecureshell
COPY --from=builder /usr/bin/sftp-* /usr/bin/
RUN apk update &&\
 apk add --no-cache openssh shadow pwgen &&\
 sed -i -e "s ^.*\(AuthorizedKeysFile\).*$ \1 /etc/ssh/auth_keys/%u "\
 /etc/ssh/sshd_config &&\
 mkdir /etc/ssh/auth_keys &&\
 cat /dev/null > /etc/motd &&\
 add-shell '/usr/bin/mysecureshell' &&\
 rm -rf /var/cache/apk/*
COPY bin/* /usr/local/bin/
COPY etc/sftp_config /etc/ssh/
COPY entrypoint.sh /
EXPOSE 22
VOLUME /sftp
ENTRYPOINT ["/entrypoint.sh"]
CMD ["server"]

The /etc/sftp_config file is used to configure the mysecureshell server to have all the user homes under /sftp/data, only allow them to see the files under their home directories as if it were at the root of the server and close idle connections after 5m of inactivity:

etc/sftp_config

# Default mysecureshell configuration
<Default>
   # All users will have access their home directory under /sftp/data
   Home /sftp/data/$USER
   # Log to a file inside /sftp/logs/ (only works when the directory exists)
   LogFile /sftp/logs/mysecureshell.log
   # Force users to stay in their home directory
   StayAtHome true
   # Hide Home PATH, it will be shown as /
   VirtualChroot true
   # Hide real file/directory owner (just change displayed permissions)
   DirFakeUser true
   # Hide real file/directory group (just change displayed permissions)
   DirFakeGroup true
   # We do not want users to keep forever their idle connection
   IdleTimeOut 5m
</Default>
# vim: ts=2:sw=2:et

The entrypoint.sh script is the one responsible to prepare the container for the users included on the /secrets/user_pass.txt file (creates the users with their HOME directories under /sftp/data and a /bin/false shell and creates the key files from /secrets/user_keys.txt if available). The script expects a couple of environment variables:

• SFTP_UID: UID used to run the daemon and for all the files, it has to be different than 0 (all the files managed by this daemon are going to be owned by the same user and group, even if the remote users are different).
• SFTP_GID: GID used to run the daemon and for all the files, it has to be different than 0.

And can use the SSH_PORT and SSH_PARAMS values if present. It also requires the following files (they can be mounted as secrets in kubernetes):

• /secrets/host_keys.txt: Text file containing the ssh server keys in mime format; the file is processed using the reformime utility (the one included on busybox) and can be generated using the gen-host-keys script included on the container (it uses ssh-keygen and makemime).
• /secrets/user_pass.txt: Text file containing lines of the form username:password_in_clear_text (only the users included on this file are available on the sftp server, in fact in our deployment we use only the scs user for everything).

And optionally can use another one:

• /secrets/user_keys.txt: Text file that contains lines of the form username:public_ssh_ed25519_or_rsa_key; the public keys are installed on the server and can be used to log into the sftp server if the username exists on the user_pass.txt file.

The contents of the entrypoint.sh script are:

entrypoint.sh

#!/bin/sh
set -e
# ---------
# VARIABLES
# ---------
# Expects SSH_UID & SSH_GID on the environment and uses the value of the
# SSH_PORT & SSH_PARAMS variables if present
# SSH_PARAMS
SSH_PARAMS="-D -e -p $ SSH_PORT:=22  $ SSH_PARAMS "
# Fixed values
# DIRECTORIES
HOME_DIR="/sftp/data"
CONF_FILES_DIR="/secrets"
AUTH_KEYS_PATH="/etc/ssh/auth_keys"
# FILES
HOST_KEYS="$CONF_FILES_DIR/host_keys.txt"
USER_KEYS="$CONF_FILES_DIR/user_keys.txt"
USER_PASS="$CONF_FILES_DIR/user_pass.txt"
USER_SHELL_CMD="/usr/bin/mysecureshell"
# TYPES
HOST_KEY_TYPES="dsa ecdsa ed25519 rsa"
# ---------
# FUNCTIONS
# ---------
# Validate HOST_KEYS, USER_PASS, SFTP_UID and SFTP_GID
_check_environment()  
  # Check the ssh server keys ... we don't boot if we don't have them
  if [ ! -f "$HOST_KEYS" ]; then
    cat <<EOF
We need the host keys on the '$HOST_KEYS' file to proceed.
Call the 'gen-host-keys' script to create and export them on a mime file.
EOF
    exit 1
  fi
  # Check that we have users ... if we don't we can't continue
  if [ ! -f "$USER_PASS" ]; then
    cat <<EOF
We need at least the '$USER_PASS' file to provision users.
Call the 'gen-users-tar' script to create a tar file to create an archive that
contains public and private keys for users, a 'user_keys.txt' with the public
keys of the users and a 'user_pass.txt' file with random passwords for them 
(pass the list of usernames to it).
EOF
    exit 1
  fi
  # Check SFTP_UID
  if [ -z "$SFTP_UID" ]; then
    echo "The 'SFTP_UID' can't be empty, pass a 'GID'."
    exit 1
  fi
  if [ "$SFTP_UID" -eq "0" ]; then
    echo "The 'SFTP_UID' can't be 0, use a different 'UID'"
    exit 1
  fi
  # Check SFTP_GID
  if [ -z "$SFTP_GID" ]; then
    echo "The 'SFTP_GID' can't be empty, pass a 'GID'."
    exit 1
  fi
  if [ "$SFTP_GID" -eq "0" ]; then
    echo "The 'SFTP_GID' can't be 0, use a different 'GID'"
    exit 1
  fi
 
# Adjust ssh host keys
_setup_host_keys()  
  opwd="$(pwd)"
  tmpdir="$(mktemp -d)"
  cd "$tmpdir"
  ret="0"
  reformime <"$HOST_KEYS"   ret="1"
  for kt in $HOST_KEY_TYPES; do
    key="ssh_host_$ kt _key"
    pub="ssh_host_$ kt _key.pub"
    if [ ! -f "$key" ]; then
      echo "Missing '$key' file"
      ret="1"
    fi
    if [ ! -f "$pub" ]; then
      echo "Missing '$pub' file"
      ret="1"
    fi
    if [ "$ret" -ne "0" ]; then
      continue
    fi
    cat "$key" >"/etc/ssh/$key"
    chmod 0600 "/etc/ssh/$key"
    chown root:root "/etc/ssh/$key"
    cat "$pub" >"/etc/ssh/$pub"
    chmod 0600 "/etc/ssh/$pub"
    chown root:root "/etc/ssh/$pub"
  done
  cd "$opwd"
  rm -rf "$tmpdir"
  return "$ret"
 
# Create users
_setup_user_pass()  
  opwd="$(pwd)"
  tmpdir="$(mktemp -d)"
  cd "$tmpdir"
  ret="0"
  [ -d "$HOME_DIR" ]   mkdir "$HOME_DIR"
  # Make sure the data dir can be managed by the sftp user
  chown "$SFTP_UID:$SFTP_GID" "$HOME_DIR"
  # Allow the user (and root) to create directories inside the $HOME_DIR, if
  # we don't allow it the directory creation fails on EFS (AWS)
  chmod 0755 "$HOME_DIR"
  # Create users
  echo "sftp:sftp:$SFTP_UID:$SFTP_GID:::/bin/false" >"newusers.txt"
  sed -n "/^[^#]/   s/:/ /p  " "$USER_PASS"   while read -r _u _p; do
    echo "$_u:$_p:$SFTP_UID:$SFTP_GID::$HOME_DIR/$_u:$USER_SHELL_CMD"
  done >>"newusers.txt"
  newusers --badnames newusers.txt
  # Disable write permission on the directory to forbid remote sftp users to
  # remove their own root dir (they have already done it); we adjust that
  # here to avoid issues with EFS (see before)
  chmod 0555 "$HOME_DIR"
  # Clean up the tmpdir
  cd "$opwd"
  rm -rf "$tmpdir"
  return "$ret"
 
# Adjust user keys
_setup_user_keys()  
  if [ -f "$USER_KEYS" ]; then
    sed -n "/^[^#]/   s/:/ /p  " "$USER_KEYS"   while read -r _u _k; do
      echo "$_k" >>"$AUTH_KEYS_PATH/$_u"
    done
  fi
 
# Main function
exec_sshd()  
  _check_environment
  _setup_host_keys
  _setup_user_pass
  _setup_user_keys
  echo "Running: /usr/sbin/sshd $SSH_PARAMS"
  # shellcheck disable=SC2086
  exec /usr/sbin/sshd -D $SSH_PARAMS
 
# ----
# MAIN
# ----
case "$1" in
"server") exec_sshd ;;
*) exec "$@" ;;
esac
# vim: ts=2:sw=2:et

The container also includes a couple of auxiliary scripts, the first one can be used to generate the host_keys.txt file as follows:

$ docker run --rm stodh/mysecureshell gen-host-keys > host_keys.txt

Where the script is as simple as:

bin/gen-host-keys

#!/bin/sh
set -e
# Generate new host keys
ssh-keygen -A >/dev/null
# Replace hostname
sed -i -e 's/@.*$/@mysecureshell/' /etc/ssh/ssh_host_*_key.pub
# Print in mime format (stdout)
makemime /etc/ssh/ssh_host_*
# vim: ts=2:sw=2:et

And there is another script to generate a .tar file that contains auth data for the list of usernames passed to it (the file contains a user_pass.txt file with random passwords for the users, public and private ssh keys for them and the user_keys.txt file that matches the generated keys). To generate a tar file for the user scs we can execute the following:

$ docker run --rm stodh/mysecureshell gen-users-tar scs > /tmp/scs-users.tar

To see the contents and the text inside the user_pass.txt file we can do:

$ tar tvf /tmp/scs-users.tar
-rw-r--r-- root/root        21 2022-09-11 15:55 user_pass.txt
-rw-r--r-- root/root       822 2022-09-11 15:55 user_keys.txt
-rw------- root/root       387 2022-09-11 15:55 id_ed25519-scs
-rw-r--r-- root/root        85 2022-09-11 15:55 id_ed25519-scs.pub
-rw------- root/root      3357 2022-09-11 15:55 id_rsa-scs
-rw------- root/root      3243 2022-09-11 15:55 id_rsa-scs.pem
-rw-r--r-- root/root       729 2022-09-11 15:55 id_rsa-scs.pub
$ tar xfO /tmp/scs-users.tar user_pass.txt
scs:20JertRSX2Eaar4x

The source of the script is:

bin/gen-users-tar

#!/bin/sh
set -e
# ---------
# VARIABLES
# ---------
USER_KEYS_FILE="user_keys.txt"
USER_PASS_FILE="user_pass.txt"
# ---------
# MAIN CODE
# ---------
# Generate user passwords and keys, return 1 if no username is received
if [ "$#" -eq "0" ]; then
  return 1
fi
opwd="$(pwd)"
tmpdir="$(mktemp -d)"
cd "$tmpdir"
for u in "$@"; do
  ssh-keygen -q -a 100 -t ed25519 -f "id_ed25519-$u" -C "$u" -N ""
  ssh-keygen -q -a 100 -b 4096 -t rsa -f "id_rsa-$u" -C "$u" -N ""
  # Legacy RSA private key format
  cp -a "id_rsa-$u" "id_rsa-$u.pem"
  ssh-keygen -q -p -m pem -f "id_rsa-$u.pem" -N "" -P "" >/dev/null
  chmod 0600 "id_rsa-$u.pem"
  echo "$u:$(pwgen -s 16 1)" >>"$USER_PASS_FILE"
  echo "$u:$(cat "id_ed25519-$u.pub")" >>"$USER_KEYS_FILE"
  echo "$u:$(cat "id_rsa-$u.pub")" >>"$USER_KEYS_FILE"
done
tar cf - "$USER_PASS_FILE" "$USER_KEYS_FILE" id_* 2>/dev/null
cd "$opwd"
rm -rf "$tmpdir"
# vim: ts=2:sw=2:et

nginx-scsThe nginx-scs container is generated using the following Dockerfile:

ARG NGINX_VERSION=1.23.1
FROM nginx:$NGINX_VERSION
LABEL maintainer="Sergio Talens-Oliag <sto@mixinet.net>"
RUN rm -f /docker-entrypoint.d/*
COPY docker-entrypoint.d/* /docker-entrypoint.d/

Basically we are removing the existing docker-entrypoint.d scripts from the standard image and adding a new one that configures the web server as we want using a couple of environment variables:

• AUTH_REQUEST_URI: URL to use for the auth_request, if the variable is not found on the environment auth_request is not used.
• HTML_ROOT: Base directory of the web server, if not passed the default /usr/share/nginx/html is used.

Note that if we don t pass the variables everything works as if we were using the original nginx image. The contents of the configuration script are:

docker-entrypoint.d/10-update-default-conf.sh

#!/bin/sh
# Replace the default.conf nginx file by our own version.
set -e
if [ -z "$HTML_ROOT" ]; then
  HTML_ROOT="/usr/share/nginx/html"
fi
if [ "$AUTH_REQUEST_URI" ]; then
  cat >/etc/nginx/conf.d/default.conf <<EOF
server  
  listen       80;
  server_name  localhost;
  location /  
    auth_request /.auth;
    root  $HTML_ROOT;
    index index.html index.htm;
   
  location /.auth  
    internal;
    proxy_pass $AUTH_REQUEST_URI;
    proxy_pass_request_body off;
    proxy_set_header Content-Length "";
    proxy_set_header X-Original-URI \$request_uri;
   
  error_page   500 502 503 504  /50x.html;
  location = /50x.html  
    root /usr/share/nginx/html;
   
 
EOF
else
  cat >/etc/nginx/conf.d/default.conf <<EOF
server  
  listen       80;
  server_name  localhost;
  location /  
    root  $HTML_ROOT;
    index index.html index.htm;
   
  error_page   500 502 503 504  /50x.html;
  location = /50x.html  
    root /usr/share/nginx/html;
   
 
EOF
fi
# vim: ts=2:sw=2:et

As we will see later the idea is to use the /sftp/data or /sftp/data/scs folder as the root of the web published by this container and create an Ingress object to provide access to it outside of our kubernetes cluster.

webhook-scsThe webhook-scs container is generated using the following Dockerfile:

ARG ALPINE_VERSION=3.16.2
ARG GOLANG_VERSION=alpine3.16
FROM golang:$GOLANG_VERSION AS builder
LABEL maintainer="Sergio Talens-Oliag <sto@mixinet.net>"
ENV WEBHOOK_VERSION 2.8.0
ENV WEBHOOK_PR 549
ENV S3FS_VERSION v1.91
WORKDIR /go/src/github.com/adnanh/webhook
RUN apk update &&\
 apk add --no-cache -t build-deps curl libc-dev gcc libgcc patch
RUN curl -L --silent -o webhook.tar.gz\
 https://github.com/adnanh/webhook/archive/$ WEBHOOK_VERSION .tar.gz &&\
 tar xzf webhook.tar.gz --strip 1 &&\
 curl -L --silent -o $ WEBHOOK_PR .patch\
 https://patch-diff.githubusercontent.com/raw/adnanh/webhook/pull/$ WEBHOOK_PR .patch &&\
 patch -p1 < $ WEBHOOK_PR .patch &&\
 go get -d && \
 go build -o /usr/local/bin/webhook
WORKDIR /src/s3fs-fuse
RUN apk update &&\
 apk add ca-certificates build-base alpine-sdk libcurl automake autoconf\
 libxml2-dev libressl-dev mailcap fuse-dev curl-dev
RUN curl -L --silent -o s3fs.tar.gz\
 https://github.com/s3fs-fuse/s3fs-fuse/archive/refs/tags/$S3FS_VERSION.tar.gz &&\
 tar xzf s3fs.tar.gz --strip 1 &&\
 ./autogen.sh &&\
 ./configure --prefix=/usr/local &&\
 make -j && \
 make install
FROM alpine:$ALPINE_VERSION
LABEL maintainer="Sergio Talens-Oliag <sto@mixinet.net>"
WORKDIR /webhook
RUN apk update &&\
 apk add --no-cache ca-certificates mailcap fuse libxml2 libcurl libgcc\
 libstdc++ rsync util-linux-misc &&\
 rm -rf /var/cache/apk/*
COPY --from=builder /usr/local/bin/webhook /usr/local/bin/webhook
COPY --from=builder /usr/local/bin/s3fs /usr/local/bin/s3fs
COPY entrypoint.sh /
COPY hooks/* ./hooks/
EXPOSE 9000
ENTRYPOINT ["/entrypoint.sh"]
CMD ["server"]

Again, we use a multi-stage build because in production we wanted to support a functionality that is not already on the official versions (streaming the command output as a response instead of waiting until the execution ends); this time we build the image applying the PATCH included on this pull request against a released version of the source instead of creating a fork. The entrypoint.sh script is used to generate the webhook configuration file for the existing hooks using environment variables (basically the WEBHOOK_WORKDIR and the *_TOKEN variables) and launch the webhook service:

entrypoint.sh

#!/bin/sh
set -e
# ---------
# VARIABLES
# ---------
WEBHOOK_BIN="$ WEBHOOK_BIN:-/webhook/hooks "
WEBHOOK_YML="$ WEBHOOK_YML:-/webhook/scs.yml "
WEBHOOK_OPTS="$ WEBHOOK_OPTS:--verbose "
# ---------
# FUNCTIONS
# ---------
print_du_yml()  
  cat <<EOF
- id: du
  execute-command: '$WEBHOOK_BIN/du.sh'
  command-working-directory: '$WORKDIR'
  response-headers:
  - name: 'Content-Type'
    value: 'application/json'
  http-methods: ['GET']
  include-command-output-in-response: true
  include-command-output-in-response-on-error: true
  pass-arguments-to-command:
  - source: 'url'
    name: 'path'
  pass-environment-to-command:
  - source: 'string'
    envname: 'OUTPUT_FORMAT'
    name: 'json'
EOF
 
print_hardlink_yml()  
  cat <<EOF
- id: hardlink
  execute-command: '$WEBHOOK_BIN/hardlink.sh'
  command-working-directory: '$WORKDIR'
  http-methods: ['GET']
  include-command-output-in-response: true
  include-command-output-in-response-on-error: true
EOF
 
print_s3sync_yml()  
  cat <<EOF
- id: s3sync
  execute-command: '$WEBHOOK_BIN/s3sync.sh'
  command-working-directory: '$WORKDIR'
  http-methods: ['POST']
  include-command-output-in-response: true
  include-command-output-in-response-on-error: true
  pass-environment-to-command:
  - source: 'payload'
    envname: 'AWS_KEY'
    name: 'aws.key'
  - source: 'payload'
    envname: 'AWS_SECRET_KEY'
    name: 'aws.secret_key'
  - source: 'payload'
    envname: 'S3_BUCKET'
    name: 's3.bucket'
  - source: 'payload'
    envname: 'S3_REGION'
    name: 's3.region'
  - source: 'payload'
    envname: 'S3_PATH'
    name: 's3.path'
  - source: 'payload'
    envname: 'SCS_PATH'
    name: 'scs.path'
  stream-command-output: true
EOF
 
print_token_yml()  
  if [ "$1" ]; then
    cat << EOF
  trigger-rule:
    match:
      type: 'value'
      value: '$1'
      parameter:
        source: 'header'
        name: 'X-Webhook-Token'
EOF
  fi
 
exec_webhook()  
  # Validate WORKDIR
  if [ -z "$WEBHOOK_WORKDIR" ]; then
    echo "Must define the WEBHOOK_WORKDIR variable!" >&2
    exit 1
  fi
  WORKDIR="$(realpath "$WEBHOOK_WORKDIR" 2>/dev/null)"   true
  if [ ! -d "$WORKDIR" ]; then
    echo "The WEBHOOK_WORKDIR '$WEBHOOK_WORKDIR' is not a directory!" >&2
    exit 1
  fi
  # Get TOKENS, if the DU_TOKEN or HARDLINK_TOKEN is defined that is used, if
  # not if the COMMON_TOKEN that is used and in other case no token is checked
  # (that is the default)
  DU_TOKEN="$ DU_TOKEN:-$COMMON_TOKEN "
  HARDLINK_TOKEN="$ HARDLINK_TOKEN:-$COMMON_TOKEN "
  S3_TOKEN="$ S3_TOKEN:-$COMMON_TOKEN "
  # Create webhook configuration
    
    print_du_yml
    print_token_yml "$DU_TOKEN"
    echo ""
    print_hardlink_yml
    print_token_yml "$HARDLINK_TOKEN"
    echo ""
    print_s3sync_yml
    print_token_yml "$S3_TOKEN"
   >"$WEBHOOK_YML"
  # Run the webhook command
  # shellcheck disable=SC2086
  exec webhook -hooks "$WEBHOOK_YML" $WEBHOOK_OPTS
 
# ----
# MAIN
# ----
case "$1" in
"server") exec_webhook ;;
*) exec "$@" ;;
esac

The entrypoint.sh script generates the configuration file for the webhook server calling functions that print a yaml section for each hook and optionally adds rules to validate access to them comparing the value of a X-Webhook-Token header against predefined values. The expected token values are taken from environment variables, we can define a token variable for each hook (DU_TOKEN, HARDLINK_TOKEN or S3_TOKEN) and a fallback value (COMMON_TOKEN); if no token variable is defined for a hook no check is done and everybody can call it. The Hook Definition documentation explains the options you can use for each hook, the ones we have right now do the following:

• du: runs on the $WORKDIR directory, passes as first argument to the script the value of the path query parameter and sets the variable OUTPUT_FORMAT to the fixed value json (we use that to print the output of the script in JSON format instead of text).
• hardlink: runs on the $WORKDIR directory and takes no parameters.
• s3sync: runs on the $WORKDIR directory and sets a lot of environment variables from values read from the JSON encoded payload sent by the caller (all the values must be sent by the caller even if they are assigned an empty value, if they are missing the hook fails without calling the script); we also set the stream-command-output value to true to make the script show its output as it is working (we patched the webhook source to be able to use this option).

The du hook scriptThe du hook script code checks if the argument passed is a directory, computes its size using the du command and prints the results in text format or as a JSON dictionary:

hooks/du.sh

#!/bin/sh
set -e
# Script to print disk usage for a PATH inside the scs folder
# ---------
# FUNCTIONS
# ---------
print_error()  
  if [ "$OUTPUT_FORMAT" = "json" ]; then
    echo " \"error\":\"$*\" "
  else
    echo "$*" >&2
  fi
  exit 1
 
usage()  
  if [ "$OUTPUT_FORMAT" = "json" ]; then
    echo " \"error\":\"Pass arguments as '?path=XXX\" "
  else
    echo "Usage: $(basename "$0") PATH" >&2
  fi
  exit 1
 
# ----
# MAIN
# ----
if [ "$#" -eq "0" ]   [ -z "$1" ]; then
  usage
fi
if [ "$1" = "." ]; then
  DU_PATH="./"
else
  DU_PATH="$(find . -name "$1" -mindepth 1 -maxdepth 1)"   true
fi
if [ -z "$DU_PATH" ]   [ ! -d "$DU_PATH/." ]; then
  print_error "The provided PATH ('$1') is not a directory"
fi
# Print disk usage in bytes for the given PATH
OUTPUT="$(du -b -s "$DU_PATH")"
if [ "$OUTPUT_FORMAT" = "json" ]; then
  # Format output as  "path":"PATH","bytes":"BYTES" 
  echo "$OUTPUT"  
    sed -e "s%^\(.*\)\t.*/\(.*\)$% \"path\":\"\2\",\"bytes\":\"\1\" %"  
    tr -d '\n'
else
  # Print du output as is
  echo "$OUTPUT"
fi
# vim: ts=2:sw=2:et:ai:sts=2

The hardlink hook scriptThe hardlink hook script is really simple, it just runs the util-linux version of the hardlink command on its working directory:

hooks/hardlink.sh

#!/bin/sh
hardlink --ignore-time --maximize .

We use that to reduce the size of the stored content; to manage versions of files and folders we keep each version on a separate directory and when one or more files are not changed this script makes them hardlinks to the same file on disc, reducing the space used on disk.

The s3sync hook scriptThe s3sync hook script uses the s3fs tool to mount a bucket and synchronise data between a folder inside the bucket and a directory on the filesystem using rsync; all values needed to execute the task are taken from environment variables:

hooks/s3sync.sh

#!/bin/ash
set -euo pipefail
set -o errexit
set -o errtrace
# Functions
finish()  
  ret="$1"
  echo ""
  echo "Script exit code: $ret"
  exit "$ret"
 
# Check variables
if [ -z "$AWS_KEY" ]   [ -z "$AWS_SECRET_KEY" ]   [ -z "$S3_BUCKET" ]  
  [ -z "$S3_PATH" ]   [ -z "$SCS_PATH" ]; then
  [ "$AWS_KEY" ]   echo "Set the AWS_KEY environment variable"
  [ "$AWS_SECRET_KEY" ]   echo "Set the AWS_SECRET_KEY environment variable"
  [ "$S3_BUCKET" ]   echo "Set the S3_BUCKET environment variable"
  [ "$S3_PATH" ]   echo "Set the S3_PATH environment variable"
  [ "$SCS_PATH" ]   echo "Set the SCS_PATH environment variable"
  finish 1
fi
if [ "$S3_REGION" ] && [ "$S3_REGION" != "us-east-1" ]; then
  EP_URL="endpoint=$S3_REGION,url=https://s3.$S3_REGION.amazonaws.com"
else
  EP_URL="endpoint=us-east-1"
fi
# Prepare working directory
WORK_DIR="$(mktemp -p "$HOME" -d)"
MNT_POINT="$WORK_DIR/s3data"
PASSWD_S3FS="$WORK_DIR/.passwd-s3fs"
# Check the moutpoint
if [ ! -d "$MNT_POINT" ]; then
  mkdir -p "$MNT_POINT"
elif mountpoint "$MNT_POINT"; then
  echo "There is already something mounted on '$MNT_POINT', aborting!"
  finish 1
fi
# Create password file
touch "$PASSWD_S3FS"
chmod 0400 "$PASSWD_S3FS"
echo "$AWS_KEY:$AWS_SECRET_KEY" >"$PASSWD_S3FS"
# Mount s3 bucket as a filesystem
s3fs -o dbglevel=info,retries=5 -o "$EP_URL" -o "passwd_file=$PASSWD_S3FS" \
  "$S3_BUCKET" "$MNT_POINT"
echo "Mounted bucket '$S3_BUCKET' on '$MNT_POINT'"
# Remove the password file, just in case
rm -f "$PASSWD_S3FS"
# Check source PATH
ret="0"
SRC_PATH="$MNT_POINT/$S3_PATH"
if [ ! -d "$SRC_PATH" ]; then
  echo "The S3_PATH '$S3_PATH' can't be found!"
  ret=1
fi
# Compute SCS_UID & SCS_GID (by default based on the working directory owner)
SCS_UID="$ SCS_UID:=$(stat -c "%u" "." 2>/dev/null) "   true
SCS_GID="$ SCS_GID:=$(stat -c "%g" "." 2>/dev/null) "   true
# Check destination PATH
DST_PATH="./$SCS_PATH"
if [ "$ret" -eq "0" ] && [ -d "$DST_PATH" ]; then
  mkdir -p "$DST_PATH"   ret="$?"
fi
# Copy using rsync
if [ "$ret" -eq "0" ]; then
  rsync -rlptv --chown="$SCS_UID:$SCS_GID" --delete --stats \
    "$SRC_PATH/" "$DST_PATH/"   ret="$?"
fi
# Unmount the S3 bucket
umount -f "$MNT_POINT"
echo "Called umount for '$MNT_POINT'"
# Remove mount point dir
rmdir "$MNT_POINT"
# Remove WORK_DIR
rmdir "$WORK_DIR"
# We are done
finish "$ret"
# vim: ts=2:sw=2:et:ai:sts=2

Deployment objectsThe system is deployed as a StatefulSet with one replica. Our production deployment is done on AWS and to be able to scale we use EFS for our PersistenVolume; the idea is that the volume has no size limit, its AccessMode can be set to ReadWriteMany and we can mount it from multiple instances of the Pod without issues, even if they are in different availability zones. For development we use k3d and we are also able to scale the StatefulSet for testing because we use a ReadWriteOnce PVC, but it points to a hostPath that is backed up by a folder that is mounted on all the compute nodes, so in reality Pods in different k3d nodes use the same folder on the host.

secrets.yamlThe secrets file contains the files used by the mysecureshell container that can be generated using kubernetes pods as follows (we are only creating the scs user):

$ kubectl run "mysecureshell" --restart='Never' --quiet --rm --stdin \
  --image "stodh/mysecureshell:latest" -- gen-host-keys >"./host_keys.txt"
$ kubectl run "mysecureshell" --restart='Never' --quiet --rm --stdin \
  --image "stodh/mysecureshell:latest" -- gen-users-tar scs >"./users.tar"

Once we have the files we can generate the secrets.yaml file as follows:

$ tar xf ./users.tar user_keys.txt user_pass.txt
$ kubectl --dry-run=client -o yaml create secret generic "scs-secret" \
  --from-file="host_keys.txt=host_keys.txt" \
  --from-file="user_keys.txt=user_keys.txt" \
  --from-file="user_pass.txt=user_pass.txt" > ./secrets.yaml

The resulting secrets.yaml will look like the following file (the base64 would match the content of the files, of course):

secrets.yaml

apiVersion: v1
data:
  host_keys.txt: TWlt...
  user_keys.txt: c2Nz...
  user_pass.txt: c2Nz...
kind: Secret
metadata:
  creationTimestamp: null
  name: scs-secret

pvc.yamlThe persistent volume claim for a simple deployment (one with only one instance of the statefulSet) can be as simple as this:

pvc.yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: scs-pvc
  labels:
    app.kubernetes.io/name: scs
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 8Gi

On this definition we don t set the storageClassName to use the default one.

Volumes in our development environment (k3d)In our development deployment we create the following PersistentVolume as required by the Local Persistence Volume Static Provisioner (note that the /volumes/scs-pv has to be created by hand, in our k3d system we mount the same host directory on the /volumes path of all the nodes and create the scs-pv directory by hand before deploying the persistent volume):

k3d-pv.yaml

apiVersion: v1
kind: PersistentVolume
metadata:
  name: scs-pv
  labels:
    app.kubernetes.io/name: scs
spec:
  capacity:
    storage: 8Gi
  volumeMode: Filesystem
  accessModes:
  - ReadWriteOnce
  persistentVolumeReclaimPolicy: Delete
  claimRef:
    name: scs-pvc
  storageClassName: local-storage
  local:
    path: /volumes/scs-pv
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: node.kubernetes.io/instance-type
          operator: In
          values:
          - k3s

And to make sure that everything works as expected we update the PVC definition to add the right storageClassName:

k3d-pvc.yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: scs-pvc
  labels:
    app.kubernetes.io/name: scs
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 8Gi
  storageClassName: local-storage

Volumes in our production environment (aws)In the production deployment we don t create the PersistentVolume (we are using the aws-efs-csi-driver which supports Dynamic Provisioning) but we add the storageClassName (we set it to the one mapped to the EFS driver, i.e. efs-sc) and set ReadWriteMany as the accessMode:

efs-pvc.yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: scs-pvc
  labels:
    app.kubernetes.io/name: scs
spec:
  accessModes:
  - ReadWriteMany
  resources:
    requests:
      storage: 8Gi
  storageClassName: efs-sc

statefulset.yamlThe definition of the statefulSet is as follows:

statefulset.yaml

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: scs
  labels:
    app.kubernetes.io/name: scs
spec:
  serviceName: scs
  replicas: 1
  selector:
    matchLabels:
      app: scs
  template:
    metadata:
      labels:
        app: scs
    spec:
      containers:
      - name: nginx
        image: stodh/nginx-scs:latest
        ports:
        - containerPort: 80
          name: http
        env:
        - name: AUTH_REQUEST_URI
          value: ""
        - name: HTML_ROOT
          value: /sftp/data
        volumeMounts:
        - mountPath: /sftp
          name: scs-datadir
      - name: mysecureshell
        image: stodh/mysecureshell:latest
        ports:
        - containerPort: 22
          name: ssh
        securityContext:
          capabilities:
            add:
            - IPC_OWNER
        env:
        - name: SFTP_UID
          value: '2020'
        - name: SFTP_GID
          value: '2020'
        volumeMounts:
        - mountPath: /secrets
          name: scs-file-secrets
          readOnly: true
        - mountPath: /sftp
          name: scs-datadir
      - name: webhook
        image: stodh/webhook-scs:latest
        securityContext:
          privileged: true
        ports:
        - containerPort: 9000
          name: webhook-http
        env:
        - name: WEBHOOK_WORKDIR
          value: /sftp/data/scs
        volumeMounts:
        - name: devfuse
          mountPath: /dev/fuse
        - mountPath: /sftp
          name: scs-datadir
      volumes:
      - name: devfuse
        hostPath:
          path: /dev/fuse
      - name: scs-file-secrets
        secret:
          secretName: scs-secrets
      - name: scs-datadir
        persistentVolumeClaim:
          claimName: scs-pvc

Notes about the containers:

• nginx: As this is an example the web server is not using an AUTH_REQUEST_URI and uses the /sftp/data directory as the root of the web (to get to the files uploaded for the scs user we will need to use /scs/ as a prefix on the URLs).
• mysecureshell: We are adding the IPC_OWNER capability to the container to be able to use some of the sftp-* commands inside it, but they are not really needed, so adding the capability is optional.
• webhook: We are launching this container in privileged mode to be able to use the s3fs-fuse, as it will not work otherwise for now (see this kubernetes issue); if the functionality is not needed the container can be executed with regular privileges; besides, as we are not enabling public access to this service we don t define *_TOKEN variables (if required the values should be read from a Secret object).

Notes about the volumes:

• the devfuse volume is only needed if we plan to use the s3fs command on the webhook container, if not we can remove the volume definition and its mounts.

service.yamlTo be able to access the different services on the statefulset we publish the relevant ports using the following Service object:

service.yaml

apiVersion: v1
kind: Service
metadata:
  name: scs-svc
  labels:
    app.kubernetes.io/name: scs
spec:
  ports:
  - name: ssh
    port: 22
    protocol: TCP
    targetPort: 22
  - name: http
    port: 80
    protocol: TCP
    targetPort: 80
  - name: webhook-http
    port: 9000
    protocol: TCP
    targetPort: 9000
  selector:
    app: scs

ingress.yamlTo download the scs files from the outside we can add an ingress object like the following (the definition is for testing using the localhost name):

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: scs-ingress
  labels:
    app.kubernetes.io/name: scs
spec:
  ingressClassName: nginx
  rules:
  - host: 'localhost'
    http:
      paths:
      - path: /scs
        pathType: Prefix
        backend:
          service:
            name: scs-svc
            port:
              number: 80

DeploymentTo deploy the statefulSet we create a namespace and apply the object definitions shown before:

$ kubectl create namespace scs-demo
namespace/scs-demo created
$ kubectl -n scs-demo apply -f secrets.yaml
secret/scs-secrets created
$ kubectl -n scs-demo apply -f pvc.yaml
persistentvolumeclaim/scs-pvc created
$ kubectl -n scs-demo apply -f statefulset.yaml
statefulset.apps/scs created
$ kubectl -n scs-demo apply -f service.yaml
service/scs-svc created
$ kubectl -n scs-demo apply -f ingress.yaml
ingress.networking.k8s.io/scs-ingress created

Once the objects are deployed we can check that all is working using kubectl:

$ kubectl  -n scs-demo get all,secrets,ingress
NAME        READY   STATUS    RESTARTS   AGE
pod/scs-0   3/3     Running   0          24s
NAME            TYPE       CLUSTER-IP  EXTERNAL-IP  PORT(S)                  AGE
service/scs-svc ClusterIP  10.43.0.47  <none>       22/TCP,80/TCP,9000/TCP   21s

NAME                   READY   AGE
statefulset.apps/scs   1/1     24s
NAME                         TYPE                                  DATA   AGE
secret/default-token-mwcd7   kubernetes.io/service-account-token   3      53s
secret/scs-secrets           Opaque                                3      39s
NAME                                   CLASS  HOSTS      ADDRESS     PORTS   AGE
ingress.networking.k8s.io/scs-ingress  nginx  localhost  172.21.0.5  80      17s

At this point we are ready to use the system.

Usage examples

File uploadsAs previously mentioned in our system the idea is to use the sftp server from other Pods, but to test the system we are going to do a kubectl port-forward and connect to the server using our host client and the password we have generated (it is on the user_pass.txt file, inside the users.tar archive):

$ kubectl -n scs-demo port-forward service/scs-svc 2020:22 &
Forwarding from 127.0.0.1:2020 -> 22
Forwarding from [::1]:2020 -> 22
$ PF_PID=$!
$ sftp -P 2020 scs@127.0.0.1                                                 1
Handling connection for 2020
The authenticity of host '[127.0.0.1]:2020 ([127.0.0.1]:2020)' can't be \
  established.
ED25519 key fingerprint is SHA256:eHNwCnyLcSSuVXXiLKeGraw0FT/4Bb/yjfqTstt+088.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '[127.0.0.1]:2020' (ED25519) to the list of known \
  hosts.
scs@127.0.0.1's password: **********
Connected to 127.0.0.1.
sftp> ls -la
drwxr-xr-x    2 sftp     sftp         4096 Sep 25 14:47 .
dr-xr-xr-x    3 sftp     sftp         4096 Sep 25 14:36 ..
sftp> !date -R > /tmp/date.txt                                               2
sftp> put /tmp/date.txt .
Uploading /tmp/date.txt to /date.txt
date.txt                                      100%   32    27.8KB/s   00:00
sftp> ls -l
-rw-r--r--    1 sftp     sftp           32 Sep 25 15:21 date.txt
sftp> ln date.txt date.txt.1                                                 3
sftp> ls -l
-rw-r--r--    2 sftp     sftp           32 Sep 25 15:21 date.txt
-rw-r--r--    2 sftp     sftp           32 Sep 25 15:21 date.txt.1
sftp> put /tmp/date.txt date.txt.2                                           4
Uploading /tmp/date.txt to /date.txt.2
date.txt                                      100%   32    27.8KB/s   00:00
sftp> ls -l                                                                  5
-rw-r--r--    2 sftp     sftp           32 Sep 25 15:21 date.txt
-rw-r--r--    2 sftp     sftp           32 Sep 25 15:21 date.txt.1
-rw-r--r--    1 sftp     sftp           32 Sep 25 15:21 date.txt.2
sftp> exit
$ kill "$PF_PID"
[1]  + terminated  kubectl -n scs-demo port-forward service/scs-svc 2020:22

1. We connect to the sftp service on the forwarded port with the scs user.
2. We put a file we have created on the host on the directory.
3. We do a hard link of the uploaded file.
4. We put a second copy of the file we created locally.
5. On the file list we can see that the two first files have two hardlinks

File retrievalsIf our ingress is configured right we can download the date.txt file from the URL http://localhost/scs/date.txt:

$ curl -s http://localhost/scs/date.txt
Sun, 25 Sep 2022 17:21:51 +0200

Use of the webhook containerTo finish this post we are going to show how we can call the hooks directly, from a CronJob and from a Job.

Direct script call (du)In our deployment the direct calls are done from other Pods, to simulate it we are going to do a port-forward and call the script with an existing PATH (the root directory) and a bad one:

$ kubectl -n scs-demo port-forward service/scs-svc 9000:9000 >/dev/null &
$ PF_PID=$!
$ JSON="$(curl -s "http://localhost:9000/hooks/du?path=.")"
$ echo $JSON
 "path":"","bytes":"4160" 
$ JSON="$(curl -s "http://localhost:9000/hooks/du?path=foo")"
$ echo $JSON
 "error":"The provided PATH ('foo') is not a directory" 
$ kill $PF_PID

As we only have files on the base directory we print the disk usage of the . PATH and the output is in json format because we export OUTPUT_FORMAT with the value json on the webhook configuration.

Cronjobs (hardlink)As explained before, the webhook container can be used to run cronjobs; the following one uses an alpine container to call the hardlink script each minute (that setup is for testing, obviously):

webhook-cronjob.yaml

apiVersion: batch/v1
kind: CronJob
metadata:
  name: hardlink
  labels:
    cronjob: 'hardlink'
spec:
  schedule: "* */1 * * *"
  concurrencyPolicy: Replace
  jobTemplate:
    spec:
      template:
        metadata:
          labels:
            cronjob: 'hardlink'
        spec:
          containers:
          - name: hardlink-cronjob
            image: alpine:latest
            command: ["wget", "-q", "-O-", "http://scs-svc:9000/hooks/hardlink"]
          restartPolicy: Never

The following console session shows how we create the object, allow a couple of executions and remove it (in production we keep it running but once a day, not each minute):

$ kubectl -n scs-demo apply -f webhook-cronjob.yaml                          1
cronjob.batch/hardlink created
$ kubectl -n scs-demo get pods -l "cronjob=hardlink" -w                      2
NAME                      READY   STATUS    RESTARTS   AGE
hardlink-27735351-zvpnb   0/1     Pending   0          0s
hardlink-27735351-zvpnb   0/1     ContainerCreating   0          0s
hardlink-27735351-zvpnb   0/1     Completed           0          2s
^C
$ kubectl -n scs-demo logs pod/hardlink-27735351-zvpnb                       3
Mode:                     real
Method:                   sha256
Files:                    3
Linked:                   1 files
Compared:                 0 xattrs
Compared:                 1 files
Saved:                    32 B
Duration:                 0.000220 seconds
$ sleep 60
$ kubectl -n scs-demo get pods -l "cronjob=hardlink"                         4
NAME                      READY   STATUS      RESTARTS   AGE
hardlink-27735351-zvpnb   0/1     Completed   0          83s
hardlink-27735352-br5rn   0/1     Completed   0          23s
$ kubectl -n scs-demo logs pod/hardlink-27735352-br5rn                       5
Mode:                     real
Method:                   sha256
Files:                    3
Linked:                   0 files
Compared:                 0 xattrs
Compared:                 0 files
Saved:                    0 B
Duration:                 0.000070 seconds
$ kubectl -n scs-demo delete -f webhook-cronjob.yaml                         6
cronjob.batch "hardlink" deleted

1. This command creates the cronjob object.
2. This checks the pods with our cronjob label, we interrupt it once we see that the first run has been completed.
3. With this command we see the output of the execution, as this is the fist execution we see that date.txt.2 has been replaced by a hardlink (the summary does not name the file, but it is the only option knowing the contents from the original upload).
4. After waiting a little bit we check the pods executed again to get the name of the latest one.
5. The log now shows that nothing was done.
6. As this is a demo, we delete the cronjob.

Jobs (s3sync)The following job can be used to synchronise the contents of a directory in a S3 bucket with the SCS Filesystem:

job.yaml

apiVersion: batch/v1
kind: Job
metadata:
  name: s3sync
  labels:
    cronjob: 's3sync'
spec:
  template:
    metadata:
      labels:
        cronjob: 's3sync'
    spec:
      containers:
      - name: s3sync-job
        image: alpine:latest
        command: 
        - "wget"
        - "-q"
        - "--header"
        - "Content-Type: application/json"
        - "--post-file"
        - "/secrets/s3sync.json"
        - "-O-"
        - "http://scs-svc:9000/hooks/s3sync"
        volumeMounts:
        - mountPath: /secrets
          name: job-secrets
          readOnly: true
      restartPolicy: Never
      volumes:
      - name: job-secrets
        secret:
          secretName: webhook-job-secrets

The file with parameters for the script must be something like this:

s3sync.json

 
  "aws":  
    "key": "********************",
    "secret_key": "****************************************"
   ,
  "s3":  
    "region": "eu-north-1",
    "bucket": "blogops-test",
    "path": "test"
   ,
  "scs":  
    "path": "test"
   
 

Once we have both files we can run the Job as follows:

$ kubectl -n scs-demo create secret generic webhook-job-secrets \            1
  --from-file="s3sync.json=s3sync.json"
secret/webhook-job-secrets created
$ kubectl -n scs-demo apply -f webhook-job.yaml                              2
job.batch/s3sync created
$ kubectl -n scs-demo get pods -l "cronjob=s3sync"                           3
NAME           READY   STATUS      RESTARTS   AGE
s3sync-zx2cj   0/1     Completed   0          12s
$ kubectl -n scs-demo logs s3sync-zx2cj                                      4
Mounted bucket 's3fs-test' on '/root/tmp.jiOjaF/s3data'
sending incremental file list
created directory ./test
./
kyso.png
Number of files: 2 (reg: 1, dir: 1)
Number of created files: 2 (reg: 1, dir: 1)
Number of deleted files: 0
Number of regular files transferred: 1
Total file size: 15,075 bytes
Total transferred file size: 15,075 bytes
Literal data: 15,075 bytes
Matched data: 0 bytes
File list size: 0
File list generation time: 0.147 seconds
File list transfer time: 0.000 seconds
Total bytes sent: 15,183
Total bytes received: 74
sent 15,183 bytes  received 74 bytes  30,514.00 bytes/sec
total size is 15,075  speedup is 0.99
Called umount for '/root/tmp.jiOjaF/s3data'
Script exit code: 0
$ kubectl -n scs-demo delete -f webhook-job.yaml                             5
job.batch "s3sync" deleted
$ kubectl -n scs-demo delete secrets webhook-job-secrets                     6
secret "webhook-job-secrets" deleted

1. Here we create the webhook-job-secrets secret that contains the s3sync.json file.
2. This command runs the job.
3. Checking the label cronjob=s3sync we get the Pods executed by the job.
4. Here we print the logs of the completed job.
5. Once we are finished we remove the Job.
6. And also the secret.

Final remarksThis post has been longer than I expected, but I believe it can be useful for someone; in any case, next time I ll try to explain something shorter or will split it into multiple entries.