X-Git-Url: http://pere.pagekite.me/gitweb/homepage.git/blobdiff_plain/5dd63715ebae322e26b87a6a488a11da2e899ac3..93ddf11b60fb9f5875e9e5dfd4c1ba034b6f60e9:/blog/index.rss diff --git a/blog/index.rss b/blog/index.rss index 2c339785e6..7254b8480e 100644 --- a/blog/index.rss +++ b/blog/index.rss @@ -6,6 +6,70 @@ http://people.skolelinux.org/pere/blog/ + + Debian now with ZFS on Linux included + http://people.skolelinux.org/pere/blog/Debian_now_with_ZFS_on_Linux_included.html + http://people.skolelinux.org/pere/blog/Debian_now_with_ZFS_on_Linux_included.html + Thu, 12 May 2016 07:30:00 +0200 + <p>Today, after many years of hard work from many people, +<a href="http://zfsonlinux.org/">ZFS for Linux</a> finally entered +Debian. The package status can be seen on +<a href="https://tracker.debian.org/pkg/zfs-linux">the package tracker +for zfs-linux</a>. and +<a href="https://qa.debian.org/developer.php?login=pkg-zfsonlinux-devel@lists.alioth.debian.org">the +team status page</a>. If you want to help out, please join us. +<a href="http://anonscm.debian.org/gitweb/?p=pkg-zfsonlinux/zfs.git">The +source code</a> is available via git on Alioth. It would also be +great if you could help out with +<a href="https://tracker.debian.org/pkg/dkms">the dkms package</a>, as +it is an important piece of the puzzle to get ZFS working.</p> + + + + + What is the best multimedia player in Debian? + http://people.skolelinux.org/pere/blog/What_is_the_best_multimedia_player_in_Debian_.html + http://people.skolelinux.org/pere/blog/What_is_the_best_multimedia_player_in_Debian_.html + Sun, 8 May 2016 09:40:00 +0200 + <p><strong>Where I set out to figure out which multimedia player in +Debian claim support for most file formats.</strong></p> + +<p>A few years ago, I had a look at the media support for Browser +plugins in Debian, to get an idea which plugins to include in Debian +Edu. I created a script to extract the set of supported MIME types +for each plugin, and used this to find out which multimedia browser +plugin supported most file formats / media types. +<a href="https://wiki.debian.org/DebianEdu/BrowserMultimedia">The +result</a> can still be seen on the Debian wiki, even though it have +not been updated for a while. But browser plugins are less relevant +these days, so I thought it was time to look at standalone +players.</p> + +<p>A few days ago I was tired of VLC not being listed as a viable +player when I wanted to play videos from the Norwegian National +Broadcasting Company, and decided to investigate why. The cause is a +<a href="https://bugs.debian.org/822245">missing MIME type in the VLC +desktop file</a>. In the process I wrote a script to compare the set +of MIME types announced in the desktop file and the browser plugin, +only to discover that there is quite a large difference between the +two for VLC. This discovery made me dig up the script I used to +compare browser plugins, and adjust it to compare desktop files +instead, to try to figure out which multimedia player in Debian +support most file formats.</p> + +<p>The result can be seen on the Debian Wiki, as +<a href="https://wiki.debian.org/DebianMultimedia/PlayerSupport">a +table listing all MIME types supported by one of the packages included +in the table</a>, with the package supporting most MIME types being +listed first in the table.</p> + +</p>The best multimedia player in Debian? It is totem, followed by +parole, kplayer, mpv, vlc, smplayer mplayer-gui gnome-mpv and +kmplayer. Time for the other players to update their announced MIME +support?</p> + + + The Pyra - handheld computer with Debian preinstalled http://people.skolelinux.org/pere/blog/The_Pyra___handheld_computer_with_Debian_preinstalled.html @@ -727,176 +791,5 @@ omsorgsdepartementet fikk ny plassering i lista.</p> - - syslog-trusted-timestamp - chain of trusted timestamps for your syslog - http://people.skolelinux.org/pere/blog/syslog_trusted_timestamp___chain_of_trusted_timestamps_for_your_syslog.html - http://people.skolelinux.org/pere/blog/syslog_trusted_timestamp___chain_of_trusted_timestamps_for_your_syslog.html - Sat, 2 Apr 2016 09:50:00 +0200 - <p>Two years ago, I had -<a href="http://people.skolelinux.org/pere/blog/Public_Trusted_Timestamping_services_for_everyone.html">a -look at trusted timestamping options available</a>, and among -other things noted a still open -<a href="https://bugs.debian.org/742553">bug in the tsget script</a> -included in openssl that made it harder than necessary to use openssl -as a trusted timestamping client. A few days ago I was told -<a href="https:/www.difi.no/">the Norwegian government office DIFI</a> is -close to releasing their own trusted timestamp service, and in the -process I was happy to learn about a replacement for the tsget script -using only curl:</p> - -<p><pre> -openssl ts -query -data "/etc/shells" -cert -sha256 -no_nonce \ - | curl -s -H "Content-Type: application/timestamp-query" \ - --data-binary "@-" http://zeitstempel.dfn.de > etc-shells.tsr -openssl ts -reply -text -in etc-shells.tsr -</pre></p> - -<p>This produces a binary timestamp file (etc-shells.tsr) which can be -used to verify that the content of the file /etc/shell with the -calculated sha256 hash existed at the point in time when the request -was made. The last command extract the content of the etc-shells.tsr -in human readable form. The idea behind such timestamp is to be able -to prove using cryptography that the content of a file have not -changed since the file was stamped.</p> - -<p>To verify that the file on disk match the public key signature in -the timestamp file, run the following commands. It make sure you have -the required certificate for the trusted timestamp service available -and use it to compare the file content with the timestamp. In -production, one should of course use a better method to verify the -service certificate.</p> - -<p><pre> -wget -O ca-cert.txt https://pki.pca.dfn.de/global-services-ca/pub/cacert/chain.txt -openssl ts -verify -data /etc/shells -in etc-shells.tsr -CAfile ca-cert.txt -text -</pre></p> - -<p>Wikipedia have a lot more information about -<a href="https://en.wikipedia.org/wiki/Trusted_timestamping">trusted -Timestamping</a> and -<a href="https://en.wikipedia.org/wiki/Linked_timestamping">linked -timestamping</a>, and there are several trusted timestamping services -around, both as commercial services and as free and public services. -Among the latter is -<a href="https://www.pki.dfn.de/zeitstempeldienst/">the -zeitstempel.dfn.de service</a> mentioned above and -<a href="https://freetsa.org/">freetsa.org service</a> linked to from the -wikipedia web site. I believe the DIFI service should show up on -https://tsa.difi.no, but it is not available to the public at the -moment. I hope this will change when it is into production. The -<a href="https://tools.ietf.org/html/rfc3161">RFC 3161</a> trusted -timestamping protocol standard is even implemented in LibreOffice, -Microsoft Office and Adobe Acrobat, making it possible to verify when -a document was created.</p> - -<p>I would find it useful to be able to use such trusted timestamp -service to make it possible to verify that my stored syslog files have -not been tampered with. This is not a new idea. I found one example -implemented on the Endian network appliances where -<a href="http://help.endian.com/entries/21518508-Enabling-Timestamping-on-log-files-">the -configuration of such feature was described in 2012</a>.</p> - -<p>But I could not find any free implementation of such feature when I -searched, so I decided to try to -<a href="https://github.com/petterreinholdtsen/syslog-trusted-timestamp">build -a prototype named syslog-trusted-timestamp</a>. My idea is to -generate a timestamp of the old log files after they are rotated, and -store the timestamp in the new log file just after rotation. This -will form a chain that would make it possible to see if any old log -files are tampered with. But syslog is bad at handling kilobytes of -binary data, so I decided to base64 encode the timestamp and add an ID -and line sequence numbers to the base64 data to make it possible to -reassemble the timestamp file again. To use it, simply run it like -this: - -<p><pre> -syslog-trusted-timestamp /path/to/list-of-log-files -</pre></p> - -<p>This will send a timestamp from one or more timestamp services (not -yet decided nor implemented) for each listed file to the syslog using -logger(1). To verify the timestamp, the same program is used with the ---verify option:</p> - -<p><pre> -syslog-trusted-timestamp --verify /path/to/log-file /path/to/log-with-timestamp -</pre></p> - -<p>The verification step is not yet well designed. The current -implementation depend on the file path being unique and unchanging, -and this is not a solid assumption. It also uses process number as -timestamp ID, and this is bound to create ID collisions. I hope to -have time to come up with a better way to handle timestamp IDs and -verification later.</p> - -<p>Please check out -<a href="https://github.com/petterreinholdtsen/syslog-trusted-timestamp">the -prototype for syslog-trusted-timestamp on github</a> and send -suggestions and improvement, or let me know if there already exist a -similar system for timestamping logs already to allow me to join -forces with others with the same interest.</p> - -<p>As usual, if you use Bitcoin and want to show your support of my -activities, please send Bitcoin donations to my address -<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p> - - - - - Full battery stats collector is now available in Debian - http://people.skolelinux.org/pere/blog/Full_battery_stats_collector_is_now_available_in_Debian.html - http://people.skolelinux.org/pere/blog/Full_battery_stats_collector_is_now_available_in_Debian.html - Wed, 23 Mar 2016 22:10:00 +0100 - <p>Since this morning, the battery-stats package in Debian include an -extended collector that will collect the complete battery history for -later processing and graphing. The original collector store the -battery level as percentage of last full level, while the new -collector also record battery vendor, model, serial number, design -full level, last full level and current battery level. This make it -possible to predict the lifetime of the battery as well as visualise -the energy flow when the battery is charging or discharging.</p> - -<p>The new tools are available in <tt>/usr/share/battery-stats/</tt> -in the version 0.5.1 package in unstable. Get the new battery level graph -and lifetime prediction by running: - -<p><pre> -/usr/share/battery-stats/battery-stats-graph /var/log/battery-stats.csv -</pre></p> - -<p>Or select the 'Battery Level Graph' from your application menu.</p> - -<p>The flow in/out of the battery can be seen by running (no menu -entry yet):</p> - -<p><pre> -/usr/share/battery-stats/battery-stats-graph-flow -</pre></p> - -<p>I'm not quite happy with the way the data is visualised, at least -when there are few data points. The graphs look a bit better with a -few years of data.</p> - -<p>A while back one important feature I use in the battery stats -collector broke in Debian. The scripts in -<tt>/usr/lib/pm-utils/power.d/</tt> were no longer executed. I -suspect it happened when Jessie started using systemd, but I do not -know. The issue is reported as -<a href="https://bugs.debian.org/818649">bug #818649</a> against -pm-utils. I managed to work around it by adding an udev rule to call -the collector script every time the power connector is connected and -disconnected. With this fix in place it was finally time to make a -new release of the package, and get it into Debian.</p> - -<p>If you are interested in how your laptop battery is doing, please -check out the -<a href="https://tracker.debian.org/pkg/battery-stats">battery-stats</a> -in Debian unstable, or rebuild it on Jessie to get it working on -Debian stable. :) The upstream source is available from -<a href="https://github.com/petterreinholdtsen/battery-stats">github</a>. -As always, patches are very welcome.</p> - - -