Fosscomm 2015 at Athens
Fosscomm is the annual conference of the Greek Free Software communities. This year the event took place on November 7 & 8 at the Technological Educational Institute(TEI) of Athens. This time around openSUSE had quite the strong presence in the conference with 3 talks and a booth.
openSUSE-el
The Booth itself always had at least 3 persons busy answering questions with old time and some new contributors to the project and local community handling the organization and distribution of the swag in the booth and explaining the merits of our current structure, projects and releases.
Enlightening Lizards
Although i haven’t had time to really contribute to this project in a while, it’s still one i really hold dear/close to heart so made sure to do this presentation again this year but with updated stats to spread the word about this awesome window manager and its foundation libraries and the stellar packaging work done by simon lees.
Automated Testing With openQA
My second and I believe most important presentation, this year, was about the excellent QA tool actually used to build our distro, “openQA”. As said by it’s motto, “Life is too short for manual testing!”, thus openQA is used to automate testing of the whole distribution (either as a collection or in individual package basis). You can see some test case examples on it’s homepage, you can also fetch the presentation from my github repo (FOSSCOMM_2015 directory) linked in the blog sidebar.
Leaping Ahead
Alex Vennos another community member had a presentation about the latest stable release “Leap 42.1”, unfortunately i couldn’t attend it but heard that it was well received even though people showed some confusion about the sudden “Leap” to a version like 42.1 from the previous 13.2
The rest
I spent the rest of the conference at our booth helping people, answering questions and generally socializing and talking with old & new friends.
Congratulations to the people from the TEI of Athens for the organization! :)
Update minor (mostly grammar/typo fixes)
2015 Learning Retrospective
- The year began well. Started working on keeri with an aim to implement a distributed database, thereby learning the distributed systems concepts and leveraging my storage / filesystem experience.
- Took the coursera's cloud computing concepts course to understand the fundamentals that will help in implementing keeri
- As part of the database implementation, needed to implement a SQL parser which will convert given SQL statements into a decision tree. Took a coursera course on compilers. Implemented a decent recursive-descent (note the wordplay) parser that will process SQL queries with parentheses, Logical operators and Relational operators.
- Having already been tired with the non-core aspects of the "distributed" database, abandoned the project temporarily.
- Need to learn more about NewSQL technologies. Especially in the areas around how it helps for better tooling (for IDEs and the like) and also for parallelism.
- Studied a bit of database literature around ARIES, Voltdb etc.
- Attempted to read part-time parliament but lost interest midway because of reading raft, which is for similar purpose but a lot simpler to read, follow. Did a paper reading session together with Sureshkumar Thangavel for this.
- Played around with Continous Integration systems (travis, jenkins, etc.) out of interest, which later helped in projects in two different dayjobs.
- Wasted a lot of time, pretending to be preparing for interviews but did not do anything more than chatting with job change aspirants. But no complaints as time enjoyed is not time wasted.
- Learnt a little bit in more detail about queueing systems (Amazon SQS, rabbitmq to be specific)
- Wrote some test / tutorial programs for the Amazon Go SDK
- Did a few prototypes using Go for the API backend, Angular and React as the web frontends for few project ideas. Bothered about the fatigue induced by the constant reinvention in the frontend JS technologies. The future looks potentially even more heavily fragmented with no sanity in the horizon.
- Learnt to create docker images. Did some non-trivial dockerization for a legacy product with then employer. Wanted to checkout kubernetes, rocket and potentially provide patches. But lost interest.
- Wrote a bunch of long blog posts which triggered some nice private discussions. 1 2 3
- Worked a little bit on ithavi - the book on operating systems in tamil, but shamefully minuscule progress. Should do more next year at least.
- The year began well but lost steam midway, probably due to the decision to change the dayjob after 10+ years with SUSE/Novell. It led to distraction, lack of interest and some sentimental times leading to lesser productivity towards hobby projects. Hopefully the next year will be better, but with a job in a startup that works fast, I am not sure how much bandwidth I may have.
- Still not convinced if I should work on any of these system software anymore or if I should focus on some other paradigm that is at its infancy. Ken Thompson and Dennis Ritchie worked on Unix when OSes were not mature. Leslie Lamport worked on distributed systems papers which became valuable after more than two decades. Go is now using a paper on garbage collection by Dijkstra and Lamport written in the 70s. So, I am thinking if I should focus on some problems / technologies whose time has not come yet, to feel that excitement of walking on unchartered territories. There are a few options like quantum cryptography etc. which have good theorists who need programmers. If I could collaborate with such intelligent people and synergistically add some value, it will be satisfying. I briefly discussed with some researchers in India (IIT Madras, TIFR etc.) about doing a PhD or helping as an assistant. But not any progress and nothing sounds too promising if work has to be done from India, thanks to our country's brain drain and the Government of India's focus on doing research on loony vedic technologies instead of on useful things. That is enough rant for the year :)
Live ISO Multi-boot USB revisited – live-grub-stick
Earlier tool live-fat-stick uses syslinux to create multiboot USB stick/hdd on a vfat parition without having to format the stick preserving existing data and copying whole ISO so the same stick can serve as demo as well as to copy ISOs for distributing. However the disadvantages are all of them that comes from using vfat.
Grub2 has come a long way and almost all major distributions now support booting from the iso image via loopback. So here is live-grub-stick script that uses grub in place of syslinux bringing in all the advantages of using grub2.
Currently live images of openSUSE, Ubuntu, Fedora and all their clones are supported. Go ahead and fork it if you would like to add support for your distribution.
Announcing Li-f-e 42.1
The best Linux distribution for education got a whole lot better, your Li-f-e(Linux for Education) takes a “Leap” to 42.1. openSUSE Education community is proud to present this latest edition based on openSUSE 42.1 with all the features, updates and bug fixes available on it till date. This effectively makes it the only enterprise grade long term supported(LTS) distribution for Education.
As with previous releases we have bundled a ton of softwares on this live DVD/USB specially packaged for education, along with the Plasma, GNOME and Mate Desktop Environments, full multimedia experience is also provided out of the box thanks to the Packman repositories. Only x86_64 architecture is supported, if you have a lot of machines that only support x86 then read on to find out how you can extend their Li-f-e.
You can of course very easily turn Li-f-e to full-fledged LTSP server to PXE boot machines in your local network. Booting both i686 and x86_64 architectures is supported. In case you need to PXE boot machines below i686 then you would have to install this package.
Happy holidays!
Get Li-f-e from here: Direct Download | md5sum | Alternate download and mirrors
Docker Internals and Implementing Rebase
SUSE's semi-annual Hackweek was last week and I decided to work on implementing docker rebase, mainly to learn about the internal image format of Docker and see whether it was possible to improve how the updating of Docker images works in practice (either rebuilding or zypper-docker).
Configuring a Brother MFC-7460DN Laser Printer/Scanner on Fedora 23 (64-bit)
Update: the MFC-7460DN printer is now supported via the brlaser open source printer driver by Peter De Wachter. See this post for a much simpler way to configure this printer on Fedora (and other Linux distributions).
I’ve always been a fan of Brother, as their devices usually come with decent support for the Linux OS (at least initially). I have an MFC-7460DN Laser Printer / Scanner in my home office, that worked fine with Ubuntu Linux for the past few years. It’s hooked up to my DSL router’s ethernet switch and acts like a network printer for all of our devices.
Just to keep my mind flexible and to take a look at another Linux distribution for a change, I recently started using Fedora Workstation 23 on my Laptop (a company-issued Lenovo ThinkPad T440s). While the OS installation was painless and all main components like Video, Audio, Networking were detected and configured correctly out of the box, the post-installation of some tools and services required some more effort.
This time, the printing part of the MFC-7460DN took me quite some time to figure out. While Brother provides RPM packages of the drivers, they are 32-bit only, and the instructions hadn’t been updated since Fedora 12. The first thing I had to do was to download two driver RPM packages. I initially started with the newer versions of the drivers, brgenml1cupswrapper-3.1.0 and brgenml1lpr-3.1.0, but somehow did not get them to work at all. I then tried the older packages, mfc7460dnlpr-2.1.0 and cupswrapperMFC7460DN-2.0.4. These installed flawlessly, and a new printer was added to the CUPS configuration automatically.
However, it was configured as a local printer, so I first had to change the existing configuration to talk to the remote LPD port instead. While the printer configuration looked correct and no errors showed up, all print jobs simply disappeared into the bit bucket, without any visible error on the application side. Unfortunately the web-based CUPS administration tool was not much helpful, either – the button View Error Log simply returned a “Not found” error. There was no error log file in /var/log/cups, so I queried the status of the CUPS service via systemd next.
The command systemctl status -l cups then gave me a first hint:
sh: /opt/brother/Printers/BrGenML1//lpd/rawtobr3: /lib/ld-linux.so.2: bad ELF interpreter: No such file or directory
Since this is a 32-bit binary, it might help to actually install a 32-bit version of the GNU C library! I simply forgot this step, even though it’s documented in the installation instructions. A simple dnf install glibc.i686 got me over this hurdle.
Unfortunately the print jobs still did not reach the printer and disappeared in the void! Checking the CUPS error log again, I now saw this:
/usr/local/Brother/Printer/MFC7460DN/lpd/filterMFC7460DN: line 131: 11660 Done eval cat $INPUT_TEMP 11661 Broken pipe | $PSCONV $PSCONV_OP 11662 Segmentation fault | $BRCONV $BRCONV_OP PID 11602 (/usr/lib/cups/filter/brlpdwrapperMFC7460DN) exited with no errors. PID 11603 (/usr/lib/cups/backend/lpd) exited with no errors.
Hilarious. Oh well, maybe the 32-bit binary is simply too old and crashes in the new environment? Let’s take a look at the full systemd journal with journalctl! This gave me further clues:
cupsd[10951]: /usr/local/Brother/Printer/MFC7460DN/lpd/filterMFC7460DN: line 131: 11660 Done eval cat $INPUT_TEMP
cupsd[10951]: 11661 Broken pipe | $PSCONV $PSCONV_OP
cupsd[10951]: 11662 Segmentation fault | $BRCONV $BRCONV_OP
cupsd[10951]: PID 11602 (/usr/lib/cups/filter/brlpdwrapperMFC7460DN) exited with no errors.
cupsd[10951]: PID 11603 (/usr/lib/cups/backend/lpd) exited with no errors.
cupsd[10951]: time-at-completed=1449759139
cupsd[10951]: Job completed.
cupsd[10951]: Removing document files.
dbus[1190]: [system] Successfully activated service 'org.fedoraproject.Setroubleshootd'
setroubleshoot[11624]: SELinux is preventing brprintconflsr3 from using the execmem access on a process. For complete SELinux messages. run sealert -l 5d873063-1d87-4e82-b
python3[11624]: SELinux is preventing brprintconflsr3 from using the execmem access on a process.
***** Plugin catchall_boolean (89.3 confidence) suggests ******************
If you want to allow cups to execmem
Then you must tell SELinux about this by enabling the 'cups_execmem' boolean.
Do
setsebool -P cups_execmem 1
***** Plugin catchall (11.6 confidence) suggests **************************
If you believe that brprintconflsr3 should be allowed execmem access on processes labeled cupsd_t by default.
Then you should report this as a bug.
You can generate a local policy module to allow this access.
Do
allow this access for now by executing:
# grep brprintconflsr3 /var/log/audit/audit.log | audit2allow -M mypol
# semodule -i mypol.pp
OK, so SELinux seems to be getting in the way here. I did as suggested and ran the following commands:
# setsebool -P cups_execmem 1 # grep brprintconflsr3 /var/log/audit/audit.log | audit2allow -M brothermfc7460dn # semodule -i brothermfc7460dn.pp
An lo and behold, the printer started printing! Let’s hope it still does when I reboot the system…
Things I learned and that surprised me:
- The error handling in CUPS completely failed here. There was not a single end-user accessible hint that something went wrong, the print jobs just disappeared in the void.
- The move to
systemdstill has some ripple effects, e.g. the “Not found” error for the missing CUPS error log in the web UI. - Analyzing log files with
journalctlis actually quite convenient. Instead of grepping and tailing multiple logs under/var/log/, these tasks can now be performed using a single tool. - SELinux is still a bitch, even though the hints provided by
setroubleshootdwere quite useful to resolve the issues at hand.
KDE Plasma 5.5 released
Today the KDE team released a new version of it's desktop environment Plasma. It has now reached version 5.5 with a few nice new features.
New features in Plasma 5.5
For me the most important and most visible new feature is the update of Plasma's theme Breeze. This overhaul does not only mean that existing icons have been updated and improved and a few new icons have been added, but Breeze has been released for the GTK+2 and GTK+3 toolkits as well. This way GTK-based applications are now lo...
How to run Rails with PostgreSQL on openSUSE Leap 42.1
Install PostgreSQL:
sudo zypper install postgresql-server postgresql-devel
Start the database server:
sudo systemctl start postgresql
Enable server to be started on boot:
sudo systemctl enable postgresql
Switch to the postgres user to set up the database:
sudo su -l postgres
Create database user:
createuser -d USERNAME
Return to your normal user, exchange the database driver in the Gemfile from sqlite3 to pg and run
bundle install
Change the configuration of the database driver to something like:
default: &default
adapter: postgresql
username: cs
development:
<<: *default
database: APPNAME_development
test:
<<: *default
database: APPNAME_test
production:
<<: *default
database: APPNAME_production
Create the databases:rake db:create
rake db:migrate
rake db:migrate RAILS_ENV=test
That's it.
Proprietary AMD/ATI Catalyst fglrx rpms new release 15.11 (15.300.1025-1)
Time to get an update for fglrx: the new release has been build for 13.1, 13.2, Leap 42.1, and tumbleweed 20151201
Tumbleweed beware : broken Xorg
It seems since the release, that a number of report of broken xorg with gdm, ssdm and so… segfaulting
You can still use the previous version hanging on the server. But I doubt it would work better
As soon, with Sebastian Siebert we have a patch for, I will republish a new build
Informations & bugreport Sebastian’s blog or lizards.o.o
The proposed drivers support kernel up to version 4.4
AMD release note available
Sebastien Siebert making script
Sebastian Siebert posts about fglrx
If you have any problems with the driver, don’t be afraid to report to Sebastian (German and English bugreports are gladly accepted).
he will try, as far as I am able to reproduce the bug. Together with the necessary system information, he will go directly to the right place at AMD to have the bug fixed in the next driver release.
Thank you very much, Sebastian.
See below what to do in case of troubles.
Or you can also ping him on irc (freespacer)
Debugging troubles
I recommend in case of trouble the use of his script which can collect the whole informations needed to help you. then you just have to issue a simple commande in console to collect all informations, you can review them, and finally transmit them.
Check the website to get the latest.
su -c 'sh makerpm-amd-15.11.sh -ur' The system report 'amd-report.txt' was generated. [ OK ] Do you want to read the system report 'amd-report.txt' now? yes/no [y/n]: y Are you sure to upload the above-named system report to sprunge.us? yes/no [y/n]: y The report was uploaded to sprunge.us. The link is: http://sprunge.us/eMEB
Copy paste the link in the comment zone of Sebastian post
All proudly distributed by openSUSE powered server and sponsored by Ioda-Net Sàrl
Banana Pi M2 running openSUSE Tumbleweed
Following up from my earlier post about openSUSE LTSP on Banana Pi, Nora Lee from the manufacturer of the board got in touch with me and sent me a couple of their new boards- Banana Pi M2, runs on A31s quad-core CPU and has 1G RAM, powerful enough to run openSUSE Tumbleweed with Xfce Desktop.
Here is how you can get openSUSE running on Banana Pi M2.
* Extract the archive to get openSUSE-Tumbleweed-Bpi-M2-Xfce.img
* Dump openSUSE-Tumbleweed-Bpi-M2-Xfce.img on to a SD card
(dd if=/path/to/openSUSE-Tumbleweed-Bpi-M2-Xfce.img of=/dev/sdX bs=4M; sync #replace /dev/sdX with your actual SD card device)
* In case you have a bigger SD card, use yast2 disk(partitioner) to “expand” the second partition. You can use yast’s package manager to install more software. The default password for root is linux, you may want to change that first thing after booting.
I am unable to get sound on this hardware, probably their kernel is missing sound related modules, if you figure out how to get sound working drop me a line so I can include it in next release.Everything else(wifi, hdmi out, USB ports etc) works well enough.