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silver imac on top of brown wooden table

New blog layout

The blog has a new layout. Some of the most important changes:

  • Much smaller logo. The logo was taking up waaaaay too much space.
  • The thumbnails have a shadow on the main page.
  • I hope that the font is easier to read. I might tweak this later.
  • Less clutter in the sidebar!
  • The social links have moved to the Contact page.
  • The top menu is rearranged a bit.
  • The blog archive displays the full article, not just an excerpt.
  • Infinite scroll! I don’t know yet if I like it, I might change it later.
  • The blog archive has 2 columns. Again, I’m not sure about this, might change it later. Feedback is welcome, leave a comment!
  • The most recent post is displayed full width.
  • On individual posts the thumbnail image is now the background of the title.
  • I’m still not entirely happy that the author is shown at the bottom of each blog post. I’m the only author here, so that’s useless, but I have not yet found how to remove that. EDIT: fixed with some extra CSS. Thanks for the tip, Frank!

Do you have any suggestions or comments on the new layout?

black internal hdd on black surface

Find the Windows 11 product key using Linux

I have a dual boot on my desktop pc: Windows 11 and Ubuntu Linux. I hardly every use the Windows installation. Maybe for some games, but Steam has gotten better and better at supporting games on Linux. Or when you need to login on some government website with your eID and you can’t use the ItsMe app.

Many moons ago I did a boo-boo: for some reason I felt that I had to make my EFI system partition bigger. Which also meant resizing and moving all other partitions. Linux didn’t flinch but Windows pooped in its pants. Apparently that operating system is soooo legacy that it can’t cope with a simple partition move. I tried to fix it using a Windows system repair disk but the damn thing just couldn’t be arsed.

The partitions on my first hard disk

For a long time I just couldn’t be bothered with any further repair attempts. I don’t need that Windows anyway. I can always run Windows in VirtualBox if I really need it. It also means that I can nuke a 414 GiB partition and use that space for better things. As you can see in the screenshot, I mounted it on /mnt/windows with the intention of copying the directory Users/Amedee to Linux, in case there was still something of value there. Probably not, but better safe than sorry.

There’s just one small snag: for the life of me, I couldn’t find a Windows activation key, or remember where I put it. It’s not an OEM PC so the key isn’t stored in the BIOS. And I didn’t want to waste money on buying another license for an operating system that I hardly ever use.

I googled for methods to retrieve the Windows activation key. Some methods involve typing a command on the command prompt of a functioning Windows operating system, so those were not useful for me. Another method is just reading the activation key from the Windows Registry:

Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SoftwareProtectionPlatform\BackupProductKeyDefault

I don’t need a working Windows operating system to read Registry keys, I can just mount the Windows filesystem in Linux and query the Registry database files in /Windows/System32/config/. I found 2 tools for that purpose: hivexget and reglookup.

hivexget

This one is the simplest, it directly outputs the value of a registry key.

Installation:

sudo apt install --yes libhivex-bin

Usage:

hivexget /mnt/windows/Windows/System32/config/SOFTWARE \
     "\Microsoft\Windows NT\CurrentVersion\SoftwareProtectionPlatform" \
     BackupProductKeyDefault
XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

reglookup

This requires a bit more typing.

Installation:

sudo apt install --yes reglookup

Usage:

reglookup -p "/Microsoft/Windows NT/CurrentVersion/SoftwareProtectionPlatform/BackupProductKeyDefault" \
     /mnt/windows/Windows/System32/config/SOFTWARE
PATH,TYPE,VALUE,MTIME
/Microsoft/Windows NT/CurrentVersion/SoftwareProtectionPlatform/BackupProductKeyDefault,SZ,XXXXX-XXXXX-XXXXX-XXXXX-XXXXX,

The output has a header and is comma separated. Using -H removes the header, and then cut does the rest of the work;

reglookup -H -p "/Microsoft/Windows NT/CurrentVersion/SoftwareProtectionPlatform/BackupProductKeyDefault" \
     /mnt/windows/Windows/System32/config/SOFTWARE \
     | cut --delimiter="," --fields=3
XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

Unboxing the Ghent box (video in Dutch)

Last month I moved from Merelbeke to Ghent. I registered my new address on the government website, and last week I was invited to update my eID with my new address.

I made an appointment with one of the administrative centers of the city. The entire process took less than 5 minutes, and at the end I got a welcome gift: a box with a lot of information about the city services.

It’s been a while since I last did an unboxing video. The audio is in Dutch, maybe if I’m not too lazy (and only if people ask for it in the comments) I’ll provide subtitles.

Unboxing van het verwelkomingspakket van @StadGentVideos
Pocket knife with eleven blades, Chinese copy of t (pocket knives)

Convert ODT to PDF with Pandoc and LaTeX

  • Receive an ODT file (OpenDocument Text Document).
  • Everyone: opens the file with either LibreOffice or even Microsoft Office nowadays, apparently.
  • Me: uses Pandoc and LaTeX to convert the file to PDF and read it in Evince because I don’t have LibreOffice installed and I’m too lazy to upload the document to Google Docs.

I needed to review an addendum to a rental contract. (I moved! I’ll write about that later.) The addendum was sent to me in ODT format. At the time, my desktop pc was still packed in a box. On my laptop (a 2011 MacBook Air with Ubuntu 20.04) I only have the most essential software installed, which for me doesn’t include an office suite. I could install LibreOffice, but why make it easy if I can also do it the hard way? 😀

I do have Evince installed, which is a lightweight PDF viewer. To convert ODT to PDF I’m using Pandoc, which is a Swiss army knife for converting document formats. For PDF it needs the help of LaTeX, a document preparation system for typesetting.

First I installed the required software:

$ sudo apt install pandoc texlive texlive-latex-extra
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  libapache-pom-java libcommons-logging-java libcommons-parent-java libfontbox-java libpdfbox-java preview-latex-style texlive-base texlive-binaries
  texlive-fonts-recommended texlive-latex-base texlive-latex-recommended texlive-pictures texlive-plain-generic tipa
Suggested packages:
  libavalon-framework-java libcommons-logging-java-doc libexcalibur-logkit-java liblog4j1.2-java texlive-xetex texlive-luatex pandoc-citeproc
  context wkhtmltopdf librsvg2-bin groff ghc php python r-base-core libjs-mathjax node-katex perl-tk xzdec texlive-fonts-recommended-doc
  texlive-latex-base-doc python3-pygments icc-profiles libfile-which-perl libspreadsheet-parseexcel-perl texlive-latex-extra-doc
  texlive-latex-recommended-doc texlive-pstricks dot2tex prerex ruby-tcltk | libtcltk-ruby texlive-pictures-doc vprerex
The following NEW packages will be installed:
  libapache-pom-java libcommons-logging-java libcommons-parent-java libfontbox-java libpdfbox-java pandoc preview-latex-style texlive texlive-base
  texlive-binaries texlive-fonts-recommended texlive-latex-base texlive-latex-extra texlive-latex-recommended texlive-pictures texlive-plain-generic
  tipa
0 upgraded, 17 newly installed, 0 to remove and 1 not upgraded.
Need to get 116 MB of archives.
After this operation, 448 MB of additional disk space will be used.
Do you want to continue? [Y/n]

Just to compare, installing LibreOffice Writer would actually use less disk space. Pandoc is a lot faster though.

$ sudo apt install libreoffice-writer
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  libabw-0.1-1 libboost-date-time1.71.0 libboost-filesystem1.71.0 libboost-iostreams1.71.0 libboost-locale1.71.0 libclucene-contribs1v5
  libclucene-core1v5 libcmis-0.5-5v5 libe-book-0.1-1 libeot0 libepubgen-0.1-1 libetonyek-0.1-1 libexttextcat-2.0-0 libexttextcat-data libgpgmepp6
  libjuh-java libjurt-java liblangtag-common liblangtag1 libmhash2 libmwaw-0.3-3 libmythes-1.2-0 libneon27-gnutls libodfgen-0.1-1 liborcus-0.15-0
  libraptor2-0 librasqal3 librdf0 libreoffice-base-core libreoffice-common libreoffice-core libreoffice-math libreoffice-style-colibre
  libreoffice-style-tango librevenge-0.0-0 libridl-java libuno-cppu3 libuno-cppuhelpergcc3-3 libuno-purpenvhelpergcc3-3 libuno-sal3
  libuno-salhelpergcc3-3 libunoloader-java libwpd-0.10-10 libwpg-0.3-3 libwps-0.4-4 libxmlsec1 libxmlsec1-nss libyajl2 python3-uno uno-libs-private
  ure
Suggested packages:
  raptor2-utils rasqal-utils librdf-storage-postgresql librdf-storage-mysql librdf-storage-sqlite librdf-storage-virtuoso redland-utils
  libreoffice-base gstreamer1.0-plugins-bad tango-icon-theme fonts-crosextra-caladea fonts-crosextra-carlito libreoffice-java-common
The following NEW packages will be installed:
  libabw-0.1-1 libboost-date-time1.71.0 libboost-filesystem1.71.0 libboost-iostreams1.71.0 libboost-locale1.71.0 libclucene-contribs1v5
  libclucene-core1v5 libcmis-0.5-5v5 libe-book-0.1-1 libeot0 libepubgen-0.1-1 libetonyek-0.1-1 libexttextcat-2.0-0 libexttextcat-data libgpgmepp6
  libjuh-java libjurt-java liblangtag-common liblangtag1 libmhash2 libmwaw-0.3-3 libmythes-1.2-0 libneon27-gnutls libodfgen-0.1-1 liborcus-0.15-0
  libraptor2-0 librasqal3 librdf0 libreoffice-base-core libreoffice-common libreoffice-core libreoffice-math libreoffice-style-colibre
  libreoffice-style-tango libreoffice-writer librevenge-0.0-0 libridl-java libuno-cppu3 libuno-cppuhelpergcc3-3 libuno-purpenvhelpergcc3-3
  libuno-sal3 libuno-salhelpergcc3-3 libunoloader-java libwpd-0.10-10 libwpg-0.3-3 libwps-0.4-4 libxmlsec1 libxmlsec1-nss libyajl2 python3-uno
  uno-libs-private ure
0 upgraded, 52 newly installed, 0 to remove and 1 not upgraded.
Need to get 78,5 MB of archives.
After this operation, 283 MB of additional disk space will be used.
Do you want to continue? [Y/n] n
Abort.

Next, converting the file. It’s possible to tell Pandoc which file formats to use with the -f (from) and -t (to) switches, but it can usually guess correctly based on the file extensions.

$ time pandoc 2022-06-house-contract-adendum.odt -o 2022-06-house-contract-adendum.pdf

real	0m0,519s
user	0m0,475s
sys	0m0,059s

It took only half a second to convert the file. Opening LibreOffice takes a bit more time on this old laptop.

You can see the PDF document properties with pdfinfo:

$ pdfinfo 2022-06-house-contract-adendum.pdf 
Title:          
Subject:        
Keywords:       
Author:         
Creator:        LaTeX with hyperref
Producer:       pdfTeX-1.40.20
CreationDate:   Sat Jun 11 23:32:30 2022 CEST
ModDate:        Sat Jun 11 23:32:30 2022 CEST
Tagged:         no
UserProperties: no
Suspects:       no
Form:           none
JavaScript:     no
Pages:          2
Encrypted:      no
Page size:      612 x 792 pts (letter)
Page rot:       0
File size:      64904 bytes
Optimized:      no
PDF version:    1.5

I don’t want it in letter format, I want A4:

$ time pandoc -V papersize:a4 -o 2022-06-house-contract-adendum.pdf 2022-06-house-contract-adendum.odt

real	0m0,520s
user	0m0,469s
sys	0m0,060s
$ pdfinfo 2022-06-house-contract-adendum.pdf 
Title:          
Subject:        
Keywords:       
Author:         
Creator:        LaTeX with hyperref
Producer:       pdfTeX-1.40.20
CreationDate:   Sat Jun 11 23:40:16 2022 CEST
ModDate:        Sat Jun 11 23:40:16 2022 CEST
Tagged:         no
UserProperties: no
Suspects:       no
Form:           none
JavaScript:     no
Pages:          2
Encrypted:      no
Page size:      595.276 x 841.89 pts (A4)
Page rot:       0
File size:      64935 bytes
Optimized:      no
PDF version:    1.5

Then I could open the file with evince 2022-06-house-contract-adendum.pdf.

And yes, I know that addendum is with double d. 🙂

silver and black hard disk drive

Suspending cloud backup of a NAS that cannot be reached

I use CrashPlan for cloud backups. In 2018 they stopped their Home solution, so I switched to their Business plan.

It works very well on Linux, Windows and Mac, but it was always a bit fickle on my QNAP NAS. There is a qpkg package for CrashPlan, and there are lots of posts on the QNAP support forum. After 2018, none of the solutions to run a backup on the NAS itself stopped working. So I gave up, and I didn’t have a backup for almost 4 years.

Now that I have mounted most of the network shares on my local filesystem, I can just run the backup on my pc. I made 3 different backup sets, one for each of the shares. There’s only one thing that I had to fix: if Crashplan runs when the shares aren’t mounted, then it thinks that the directories are empty, and it will delete the backup on the cloud storage. As soon as the shares come back online, the files are backed up again. It doesn’t have to upload all files again, because Crashplan doesn’t purge the files on it’s cloud immediately, but the file verification still happens. That takes time and bandwidth.

I contacted CrashPlan support about this issue, and this was their reply:

I do not believe that this scenario can be avoided with this product – at least not in conjunction with your desired setup. If a location within CrashPlan’s file selection is detached from the host machine, then the program will need to rescan the selection. This is in inherent drawback to including network drives within your file selection. Your drives need to retain a stable connection in order to avoid the necessity of the software to run a new scan when it sees the drives attached to the device (so long as they’re within the file selection) detach and reattach.

Since the drive detaching will send a hardware event from the OS to CrashPlan, CrashPlan will see that that hardware event lies within its file selection – due to the fact that you mapped your network drives into a location which you’ve configured CrashPlan to watch. A hardware event pointing out that a drive within the /home/amedee/Multimedia/ file path has changed its connection status will trigger a scan. CrashPlan will not shut down upon receiving a drive detachment or attachment hardware event. The program needs to know what (if anything) is still there, and is designed firmly to track those types of changes, not to give up and stop monitoring the locations within its file selection.

There’s no way around this, aside from ensuring that you either keep a stable connection. This is an unavoidable negative consequence of mapping a network drive to a location which you’ve included in CrashPlan’s file selection. The only solution would be for you to engineer your network so as not to interrupt the connection.

Nathaniel, Technical Support Agent, Code42

I thought as much already. No problem, Nathaniel! I found a workaround: a shell script that checks if a certain marker file on the network share exists, and if it doesn’t, then the script stops the CrashPlan service, which will prevent CrashPlan from scanning the file selection. As soon as the file becomes available again, then the CrashPlan service is started. This workaround works, and is good enough for me. It may not be the cleanest solution but I’m happy with it.

I first considered using inotifywait, which listens to filesystem events like modifying or deleting files, or unmount. However when the network connection just drops for any reason, then inotifywait doesn’t get an event. So I have to resort to checking if a file exists.

#!/bin/bash
file_list="/home/amedee/bin/file_list.txt"

all_files_exist () {
    while read -r line; do
        [ -f "$line" ]
        status=$?
        if ! (exit $status); then
            echo "$line not found!"
            return $status
        fi
    done < "$file_list"
}

start_crashplan () {
    /etc/init.d/code42 start
}

stop_crashplan () {
    /etc/init.d/code42 stop
}

while true; do
    if all_files_exist; then
        start_crashplan
    else
        stop_crashplan
    fi
    sleep 60
done
  • file_list.txt contains a list of testfiles on different shares that I want to check. They all have to be present, if even only one of them is missing or can’t be reached, then the service must be stopped.
/home/amedee/Downloads/.testfile
/home/amedee/Multimedia/.testfile
/home/amedee/backup/.testfile
  • I can add or remove shares without needing to modify the script, I only need to edit file_list.txt – even while the script is still running.
  • Starting (or stopping) the service if it is already started (or stopped) is very much ok. The actual startup script itself takes care of checking if it has already started (or stopped).
  • This script needs to be run at startup as root, so I call it from cron (sudo crontab -u root -e):
@reboot /home/amedee/bin/test_cifs_shares.sh

This is what CrashPlan support replied when I told them about my workaround:

Hello Amedee,

That is excellent to hear that you have devised a solution which fits your needs!

This might not come in time to help smooth out your experience with your particular setup, but I can mark this ticket with a feature request tag. These tags help give a resource to our Product team to gauge customer interest in various features or improvements. While there is no way to use features within the program itself to properly address the scenario in which you unfortunately find yourself, as an avenue for adjustments to how the software currently operates in regards to the attachment or detachment of network drives, it’s an entirely valid request for changes in the future.

Nathaniel, Technical Support Agent, Code42

That’s very nice of you, Nathaniel! Thank you very much!

silver and black hard disk drive

Mounting NAS shares without slow startup

I have a NAS, a QNAP TS-419P II. It’s about a decade old and it has always served me well. Due to various reasons I have never used it in an efficient way, it was always like a huge external drive, not really integrated in the rest of my filesystems.

The NAS has a couple of CIFS shares with very obvious names:

  • backup
  • Download
  • Multimedia, with directories Music, Photos and Videos

(There are a few more shares, but they aren’t relevant now.)

In Ubuntu, a user home directory has these default directories:

  • Downloads
  • Music
  • Pictures
  • Videos

I want to store the files in these directories on my NAS.

Mounting shares, the obvious way

First I moved all existing files from ~/Downloads, ~/Music, ~/Pictures, ~/Videos to the corresponding directories on the NAS, to get empty directories. Then I made a few changes to the directories:

$ mkdir backup
$ mkdir Multimedia
$ rmdir Music
$ ln -s Multimedia/Music Music
$ rmdir Pictures
$ ln -s Multimedia/Photos Pictures
$ rmdir Videos
$ ln -s Multimedia/Videos Videos

The symbolic links now point to directories that don’t (yet) exist, so they appear broken – for now.

The next step is to mount the network shares to their corresponding directories.

The hostname of my NAS is minerva, after the Roman goddess of wisdom. To avoid using IP addresses, I added it’s IP address to /etc/hosts:

127.0.0.1	localhost
192.168.1.1     modem
192.168.1.63	minerva

The shares are password protected, and I don’t want to type the password each time I use the shares. So the login goes into a file /home/amedee/.smb:

username=amedee
password=NOT_GOING_TO_TELL_YOU_:-p

Even though I am the only user of this computer, it’s best practice to protect that file so I do

$ chmod 400 /home/amedee/.smb

Then I added these entries to /etc/fstab:

//minerva/download	/home/amedee/Downloads	cifs	uid=1000,gid=1000,credentials=/home/amedee/.smb,iocharset=utf8 0 0
//minerva/backup	/home/amedee/backup	cifs	uid=0,gid=1000,credentials=/home/amedee/.smb,iocharset=utf8 0 0
//minerva/multimedia	/home/amedee/Multimedia	cifs	uid=0,gid=1000,credentials=/home/amedee/.smb,iocharset=utf8 0 0
  • CIFS shares don’t have a concept of user per file, so the entire share is shown as owned by the same user. uid=1000 and gid=1000 are the user ID and group ID of the user amedee, so that all files appear to be owned by me when I do ls -l.
  • The credentials option points to the file with the username and password.
  • The default character encoding for mounts is iso8859-1, for legacy reasons. I may have files with funky characters, so iocharset=utf8 takes care of that.

Then I did sudo mount -a and yay, the files on the NAS appear as if they were on the local hard disk!

Fixing a slow startup

This all worked very well, until I did a reboot. It took a really, really long time to get to the login screen. I did lots of troubleshooting, which was really boring, so I’ll skip to the conclusion: the network mounts were slowing things down, and if I manually mount them after login, then there’s no problem.

It turns out that systemd provides a way to automount filesystems on demand. So they are only mounted when the operating system tries to access them. That sounds exactly like what I need.

To achieve this, I only needed to add noauto,x-systemd.automount to the mount options. I also added x-systemd.device-timeout=10, which means that systemd waits for 10 seconds, and then gives up if it’s unable to mount the share.

From now on I’ll never not use noauto,x-systemd.automount for network shares!

While researching this, I found some documentation that claims you don’t need noauto if you have x-systemd.automount in your mount options. Yours truly has tried it with and without noauto, and I can confirm, from first hand experience, that you definitely need noauto. Without it, there is still the long waiting time at login.

sky sunny wave space

Jag lĂ€r mig svenska 🇾đŸ‡Ș

Jag brukade skriva pÄ den hÀr bloggen pÄ nederlÀndska. Nu Àr det mest pÄ engelska, men undantagsvis Àr det hÀr blogginlÀgget pÄ svenska.

I september 2020 började jag lÀra mig svenska pÄ kvÀllsskolan i Aalst. Varför? Det finns flera anledningar:

  • Jag spelar nyckelharpa, ett typiskt svenskt musikinstrument. Jag gĂ„r pĂ„ kurser hemma och utomlands, ofta frĂ„n svenska lĂ€rare. Det var sĂ„ jag lĂ€rde kĂ€nna mĂ€nniskor i Sverige och dĂ„ Ă€r det bra att prata lite svenska för att hĂ„lla kontakten online.
  • NĂ€r man slĂ„r upp nĂ„got pĂ„ nĂ€tet om nyckelharpa Ă€r det ofta pĂ„ svenska. Jag har ocksĂ„ en underbar bok “Nyckelharpan – Ett unikt svenskt kulturarv” av Esbjörn Hogmark och jag vill kunna lĂ€sa den och inte bara titta pĂ„ bilderna.
  • Jag tycker att Sverige Ă€r ett vackert land som jag kanske vill besöka nĂ„gon gĂ„ng. Norge ocksĂ„, och dĂ€r talar man en mĂ€rklig dialekt av svenska. 😛
  • Jag vill gĂ„ en kurs pĂ„ Eric Sahlström Institutet i Tobo nĂ„gon gĂ„ng. DĂ„ skulle det vara bra att förstĂ„ lĂ€rarna pĂ„ deras eget sprĂ„k.
  • Jag gillar sprĂ„k och sprĂ„kinlĂ€rning! Det hĂ„ller min hjĂ€rna frĂ€sch och frisk. 😀

And if you didn’t understand anything: there’s always Google Translate!

men playing computer games

The hunt for a kernel bug, part 5

Armed with the information from my previous research on a possible kernel bug, I opened a bug report on the Ubuntu bug tracker: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1963555.

It wasn’t long until my bug got confirmed. Someone else chimed in that they had also experienced USB issues. In their case it were external drive devices. Definitely a showstopper!

As of this date, there is a beta for Ubuntu 22.04, and my hope is that this version will either include a new enough kernel (5.16 or up), or that Ubuntu developers have manually cherry-picked the commit that fixes the issue. Let’s check with the Ubuntu Kernel Team:

Ubuntu Kernel Team

Oops… based on upstream 5.15… that’s not good. Maybe they cherry-picked upstream commits? I checked https://packages.ubuntu.com/jammy/linux-generic and the kernel is currently at 5.15.0.25.27. The changelog doesn’t mention anything about xhci or usb. I guess I still have to wait a bit longer…

green and grey circuit board

I have a ridiculous amount of kernels

In previous blogposts I wrote about how I found a possible bug in the Linux kernel, or more precisely, in the kernel that Ubuntu derived from the mainline kernel.

To be able to install any kernel version 5.15.7 or higher, I also had to install libssl3.

The result is that I now have 37 kernels installed, taking up little over 2 GiB disk space:

$ (cd /boot ; ls -hgo initrd.img-* ; ls /boot/initrd.img-* | wc -l)
-rw-r--r-- 1 39M mrt  9 09:54 initrd.img-5.13.0-051300-generic
-rw-r--r-- 1 40M mrt  9 09:58 initrd.img-5.13.0-19-generic
-rw-r--r-- 1 40M mrt  9 09:58 initrd.img-5.13.0-20-generic
-rw-r--r-- 1 40M mrt  9 09:57 initrd.img-5.13.0-21-generic
-rw-r--r-- 1 44M mrt 30 17:46 initrd.img-5.13.0-22-generic
-rw-r--r-- 1 40M mrt  9 09:56 initrd.img-5.13.0-23-generic
-rw-r--r-- 1 40M mrt  9 09:56 initrd.img-5.13.0-25-generic
-rw-r--r-- 1 40M mrt  9 09:56 initrd.img-5.13.0-27-generic
-rw-r--r-- 1 40M mrt  9 09:55 initrd.img-5.13.0-28-generic
-rw-r--r-- 1 40M mrt  9 09:55 initrd.img-5.13.0-30-generic
-rw-r--r-- 1 45M mrt  9 12:02 initrd.img-5.13.0-35-generic
-rw-r--r-- 1 45M mrt 24 23:17 initrd.img-5.13.0-37-generic
-rw-r--r-- 1 45M mrt 30 17:49 initrd.img-5.13.0-39-generic
-rw-r--r-- 1 39M mrt  9 09:54 initrd.img-5.13.1-051301-generic
-rw-r--r-- 1 39M mrt  9 09:54 initrd.img-5.13.19-051319-generic
-rw-r--r-- 1 37M mrt  9 09:53 initrd.img-5.13.19-ubuntu-5.13.0-22.22
-rw-r--r-- 1 37M mrt  9 09:53 initrd.img-5.13.19-ubuntu-5.13.0-22.22-0-g3ab15e228151
-rw-r--r-- 1 37M mrt  9 09:52 initrd.img-5.13.19-ubuntu-5.13.0-22.22-317-g398351230dab
-rw-r--r-- 1 37M mrt  9 09:52 initrd.img-5.13.19-ubuntu-5.13.0-22.22-356-g8ac4e2604dae
-rw-r--r-- 1 37M mrt  9 09:52 initrd.img-5.13.19-ubuntu-5.13.0-22.22-376-gfab6fb5e61e1
-rw-r--r-- 1 37M mrt  9 09:51 initrd.img-5.13.19-ubuntu-5.13.0-22.22-386-gce5ff9b36bc3
-rw-r--r-- 1 37M mrt  9 09:51 initrd.img-5.13.19-ubuntu-5.13.0-22.22-387-g0fc979747dec
-rw-r--r-- 1 37M mrt  9 09:50 initrd.img-5.13.19-ubuntu-5.13.0-22.22-388-g20210d51e24a
-rw-r--r-- 1 37M mrt  9 09:50 initrd.img-5.13.19-ubuntu-5.13.0-22.22-388-gab2802ea6621
-rw-r--r-- 1 37M mrt  9 09:50 initrd.img-5.13.19-ubuntu-5.13.0-22.22-391-ge24e59fa409c
-rw-r--r-- 1 37M mrt  9 09:49 initrd.img-5.13.19-ubuntu-5.13.0-22.22-396-gc3d35f3acc3a
-rw-r--r-- 1 37M mrt  9 09:49 initrd.img-5.13.19-ubuntu-5.13.0-22.22-475-g79b62d0bba89
-rw-r--r-- 1 37M mrt  9 09:48 initrd.img-5.13.19-ubuntu-5.13.0-23.23
-rw-r--r-- 1 40M mrt  9 09:48 initrd.img-5.14.0-051400-generic
-rw-r--r-- 1 40M mrt  9 10:31 initrd.img-5.14.21-051421-generic
-rw-r--r-- 1 44M mrt  9 12:39 initrd.img-5.15.0-051500-generic
-rw-r--r-- 1 46M mrt  9 12:16 initrd.img-5.15.0-22-generic
-rw-r--r-- 1 46M mrt 28 23:27 initrd.img-5.15.32-051532-generic
-rw-r--r-- 1 46M mrt 17 21:12 initrd.img-5.16.0-051600-generic
-rw-r--r-- 1 48M mrt 28 23:19 initrd.img-5.16.16-051616-generic
-rw-r--r-- 1 45M mrt 28 23:11 initrd.img-5.17.0-051700-generic
-rw-r--r-- 1 46M apr  8 17:02 initrd.img-5.17.2-051702-generic
37
  • Versions 5.xx.yy-zz-generic are installed with apt.
  • Versions 5.xx.yy-05xxyy-generic are installed with the Ubuntu Mainline Kernel Installer.
  • Versions 5.xx.yy-ubuntu-5.13.0-zz.zz-nnn-g<commithash> are compiled from source, where <commithash> is the commit of the kernel repository that I compiled.

The kernels in bold are the kernels where something unexpected happens with my USB devices:

  • Ubuntu kernels 5.13.23 and up – including 5.15 kernels of Ubuntu 22.04 LTS (Jammy Jellyfish).
  • Ubuntu compiled kernels, starting 387 commits after kernel 5.13.22.
  • Mainline kernels 5.15.xx.

When Ubuntu finally bases their kernel on mainline 5.16 or higher, then the USB bug will be solved.

colorful toothed wheels

This may be a controversial opinion…

… but you don’t need --- at the start of a YAML file in Ansible.

What does the Ansible documentation say?

I know, I know, if you look at the official documentation on docs.ansible.com, then all of the examples start with ---. And if the official examples do it, then everyone should just blindly copy that without thinking, right?

Wrong! The Ansible documentation on YAML syntax says:

There’s another small quirk to YAML. All YAML files (regardless of their association with Ansible or not) can optionally begin with --- and end with .... This is part of the YAML format and indicates the start and end of a document.

© Copyright Ansible project contributors.

I’ve added the emphasis: optionally. They then continue with one example with --- at the start and ... at the end. The funny thing is, that’s about the only example on the Ansible documentation site (that I could find) that ends with .... So the end marker ... is clearly optional. What about the start marker ---?

What does the YAML specification say?

Ansible uses version 1.2 of the YAML specification and unless you are doing something really exotic, that’s the only version you should care about. Revision 1.2.0 was published in July 2009 and revision 1.2.2 in October 2021. That last revision doesn’t make any changes to the specification, it only corrects some errors and adds clarity.

Chapter 9 of the YAML spec introduces two concepts: documents and streams.

A stream can contain zero or more documents. It’s called a (character) stream because it can be something else than a file on your hard disk, for example some data that’s sent over a network connection. So your Ansible playbook file with extension .yml or .yaml is not a YAML document, it’s a YAML stream.

A document can have several parts:

  • Document prefix: optional character encoding and optional comment lines.
    Seriously, it’s 2022, are you going to make life hard for yourself and use any other encoding than ASCII or UTF-8? The default encoding that every YAML processor, inclusing Ansible, must support is UTF-8. So You Ain’t Gonna Need It.
    Comments can be placed anywhere, so don’t worry.
  • Document directives: these are instructions to the YAML processor and aren’t part of the data structure. The only directive I’ve occasionally seen in the wild is %YAML 1.2, to indicate the version of YAML used. That’s the default version for Ansible anyway, so You Ain’t Gonna Need It.
  • Document markers: a parser needs some way to know where directives stop and document content begins. That’s the directives end marker, ---. There is also a document end marker, ..., which tells a parser to stop looking for content and start scanning for directives again. If there are no markers and the first line doesn’t start with % (a directive), then a parser knows that everything is content. In real life you probably won’t ever have multiple documents in the same stream (file), instead you’ll organize your Ansible code in separate .yaml files, with playbooks and roles and tasks etc.
  • Document content: that’s the only really interesting stuff you care about.

YAML knows 3 types of documents:

  • Bare documents: don’t begin with directives or marker lines. Such documents are very “clean” as they contain nothing other than the content. This is the kind of YAML documents I prefer for Ansible.
  • Explicit documents: begin with an explicit directives end maker (---) but have no directives. This is the style that many people use if they just copy/paste examples from Stack Overflow.
  • Directives documents: start with some directives, followed by an explicit directives end marker. You don’t need directives for Ansible.

Configuring yamllint

I use ansible-lint and yamllint in a pre-commit hook to check the syntax of my Ansible files. This is currently my .yamllint.yml:

rules:
  document-start:
    present: false
  truthy:
    allowed-values: ['true', 'false', 'yes', 'no']

document-start makes sure that there is no --- at the start of a file. I also have opinions on truthy: an Ansible playbook is supposed to be readable both by machines and humans, and then it makes sense to allow the more human-readable values yes and no.

Do you also have opinions that make you change the default configuration of your linters?