Home Home > 2015 > 04
Sign up | Login

Archive for April, 2015

yast-fonts got user mode

April 29th, 2015 by

as I promised in fonts @ openSUSE, I have given per user yast-fonts setting a try in the last hackweek.

yast-fonts-user

The user setting is built on the top of distribution setting the same way as system setting is in system mode. See help of the module for more details.

With some exceptions, setting in ~/.config/fontconfig/fonts.conf should have a precedence over yast-fonts setting. But anyway, I would not combine yast-fonts user mode with other user font setting tools.

This also required to add user support to fonts-config. yast-fonts 3.1.13 and fonts-config 20150424 are on its way to Tumbleweed. User mode is experimental these days, we will see if it is viable.

Ever wanted to be a Dj with open source touch?

April 29th, 2015 by

There are plenty of Dj software available on Internet. Most popular I think are Traktor and VirtualDJ. Those are no brainier to choose and don’t support Linux. Because I’m old fart and I started doing my dang long time a go with Technics vinyl-players (and still play my gigs with them). They work as they have always worked great but I though that I need new geeky Dj system with digital vinyls because many interesting release doesn’t do vinyls anymore and I don’t like CD-format. Summarizing all of that I wanted something that what is open source and I can still attach my digital vinyls to it (so it should work with Serato or Traktor vinyls).
(more…)

zypper tab-completion and some thoughts

April 26th, 2015 by

Today I spent some hours implementing nice tab-completion for zypper. There was already a lot done 6 years ago, but the part about installing/removing packages was missing.

Now the thinking part is about the speed. For the tab-completion I needed a list of installed packages and of course we have that in our RPM database (using berkeley DB as a backend). However querying the list with rpm -qa already took over a second on a modern and fast system. On my poor netbook with a cold cache, it took 25 seconds (5 secs on second try with hot cache)… And the point is that you probably do not want to wait 5 seconds for your tab-completion to react.

So to avoid this problem, I used caching via make to produce a better format (plain text). This is then post-processed with sed in a fraction of a second – a speedup factor somewhere between 15 and 150. This makes a big difference.

In the end, I still wonder why plain text is so much faster than a DB. I guess, one reason is that the DB is optimized for retrieval of single values – e.g. rpm -q bash – this is very fast (but even there an egrep “^bash-[^-]+-[^-]+$” is more than twice as fast).

I still want to optimize zypper for better speed, so that a search might some day return in under 2 seconds. One idea for that is to not parse all those config+repo files every time, but only when they change. It could use mmaped files under /var/cache/zypp* as memory to store the binary representations. Though it might become complicated, if dynamic structures such as linked lists are involved.

The future will be interesting…

Tumbleweed with KDE Plasma 5 and Kernel 4

April 26th, 2015 by

You probably know me. I’m GNOME guy. Inside openSUSE, I helped to form team Enlightenment and team MATE. I’m happy that both are in official repositories.

I’m also passionate with Tumbleweed. All my systems are Tumbleweed.
I tried to install KDE Plasma 5. After I did it, I tried to install Kernel 4. And I did it. I have to test it little bit more though.
This tutorial has 2 parts.

Part 1: Install KDE Plasma 5

* First of all, download the ISO (I prefer net install 64bit or 32bit). Install KDE.

* Open YaST and install plasma5-session.

When you press Accept, it’ll ask you if you want to uninstall KDE 4. Press OK.


(more…)

Using openSUSE as a reverse tunnel site for Windows 7 or 8.1 remote desktop

April 20th, 2015 by

If you can’t open a hole in your office / home firewall then a reverse tunnel can let you workaround the issue.  This blog post uses cygwin, ssh and autossh to create and maintain a reverse tunnel through your firewall.

You should be aware that if you follow the below steps you will punch a hole through your firewall, so be sure and consider the security issues associated with that hole.  Many organizations require security beyond a simple login and password when connectivity is allowed from outside the firewall.  In some organizations following the below instructions without authorization from your IT security team could be a firing offense.

In theory this functionality is relatively basic, but there are lots of resources on the web that only serve to complicate the matter.  The below instructions were followed in 2015 with current SSH to create an actual working reverse tunnel.

The assumed situation is you have:

– Windows 7 or 8.1 PC behind a firewall you want to remote desktop to (the target PC)
– A openSUSE server in the cloud that you are able to ssh into and open appropriate ports and firewall holes
– A client PC from which you want to originate Remote Desktop sessions

The instructions here borrow heavily from the below blog post, but I was unable to get the tunnels to work by following the steps described at that site:

Creating persistent SSH tunnels in Windows using autossh

What has worked for me so far is:

  1. On the openSUSE server
    1. Ensure you have a user account “autossh” (or whatever you want to call it).  This will be used exclusively for reverse tunnels.
    2. Ensure you have a normal user account you can use with scp with to copy files from the target PC to the openSUSE server.
  2. On the target (destination) PC:
    1. Ensure you have remote desktop setup.  Machines on the local LAN should be able to remote desktop into the PC prior to starting this procedure.
    2. Download Cygwin (http://www.cygwin.com/)
    3. Install Cygwin, selecting the autossh and openssh packages.
    4. Start the Cygwin shell (Start -> Programs -> Cygwin).
    5. Generate a public/private key pair.
      1. At the command line, run: ssh-keygen
      2. Accept the default file locations
      3. Use an empty passphrase
    6. Copy your newly-created public key to the SSH server.
      1. scp .ssh/id_rsa.pub user_account@ssh.host.name:id_rsa.pub
  3. Add your public key to your list of authorized keys on the server.
    1. Login to your SSH server as your normal user_account
    2.  mv id_rsa.pub  /tmp
    3. su –  # become root
    4. Ensure /home/autossh/.ssh exists
      1. # ls -ld /home/autossh/.ssh
        drwxr-xr-x 2 autossh users 4096 Apr 24 2015 /home/autossh/.ssh
      2. If not: mkdir /home/autossh/.ssh; chown autossh.users /home/autossh/.ssh; chmod 755 /home/autossh/.ssh
    5. cat /tmp/id_rsa.pub >>  /home/autossh/.ssh/authorized_keys
  4. Tweak the sshd_config on the server
    1. By default openSUSE enables “AllowTcpForwarding” and “TCPKeepAlive”. Verify they are either commented out or set to “yes” in /etc/ssh/sshd_config
    2. Set “GatewayPorts yes” and “ClientAliveInterval 300” in /etc/ssh/sshd_config.  Also make sure they are not commented out.
    3. restart sshd to get the config values to be re-read:    sudo systemctl restart sshd.service
  5. Test your SSH key.
    1. Logout of your SSH sever.
    2. Login to your SSH server again, but as autossh this time. This time, your key will be used for authentication and you won’t be challenged for your login credentials. If you are not logged in automatically, review the previous steps. Or contact your server administrator.
      1. ssh autossh@@ssh.host.name
    3. Logout of your SSH server.
    4. Exit of the Cygwin shell.
  6. Test your SSH Tunnel capability
    1. Open a cmd prompt on your target PC as administrator
      1. start -> run -> cmd -> right click on “cmd” -> left click “run as administrator”
    2. C:\cygwin\bin\ssh -N -R 4489:localhost:3389 autossh@ssh.host.name
      1. Note that this should open an alternate port (4489) or your openSUSE server in the cloud.  openSUSE uses 3389 by default, so you need to use an alternate port on the openSUSE server end.
      2. Any connections to the alternate port should be funneled through the SSH tunnel back to the windows 7 PC on port 3389
    3. From a 3rd computer open a remote desktop connection to ssh.host.name:4489
      1. Note that remote desktop uses :4489 after the server name to designate an alternate port.
      2. If it acts like you’re not connecting at all, in all likelihood you’re not.  You probably have a firewall in place on the openSUSE server.
        1. Open port 4489 in your opensuse server firewall
          1. https://doc.opensuse.org/documentation/html/openSUSE_122/opensuse-security/cha.security.firewall.html#sec.security.firewall.SuSE.yast
          2. Or   “sudo /sbin/yast -> security and Users -> Firewall -> Allowed Services -> Advanced -> add 4489 to list of TCP Ports -> OK -> next -> finish -> quit
      3. retry remote desktop connection
    4. Once it works, from the Windows 7 command prompt kill the the ssh connection to your openSUSE server (contrl-C)
  7. Test your AutoSSH Tunnel capability
    1. From the CMD prompt running as administrator
      1. C:\cygwin\bin\autossh -M 20000 -N -R 4489:localhost:3389 autossh@ssh.host.name
        1. Note that-M opens a monitoring port (I’m not sure how to leverage that)  The monitoring port is opened on the server (ssh.host.name) so if you have multiple autossh commands pointed at the same server, each should use a unique monitoring port as well as a unique tunnel port (4489 in the above.)
    2. From a 3rd computer open a remote desktop connection to ssh.host.name:4489
      1. Make sure you terminate your remote desktop session from the 3rd computer when done testing
    3. If it worked, from the Windows 7 command prompt kill the autossh command (contrl-C)
    4. exit out of your cmd window
  • At this point you can manually invoke autossh to setup a semi-persistent tunnel

Setup the autossh feature as a Windows service

Note:

  • the below uses cygrunsrv to install the Windows service.  If you experience problems cygrunsrv -L, cyrunsrv -LV, and cygrunsrv -R <service>    may all be useful for diagnosing the problem.  The first 2 commands list the installed services, and -R removes installed services.
  • Logs for cygrunsrv default to C:\cygwin\var\log\AutoSSH.log
  1. Install autossh as a Windows service
    1. Open a cmd prompt on your target PC as administrator
      1. start -> run -> cmd -> right click on “cmd” -> left click “run as administrator”
    2. cd C:\cygwin\bin
    3. cygrunsrv -I AutoSSH -p /bin/autossh -a “-M 20000 -N -R 4489:localhost:3389 autossh@ssh.host.name” -e AUTOSSH_NTSERVICE=yes
      1. If you get an error with this command, manually type the ” marks.  They may not be handled properly with cut&paste.
      2. Be very careful with the above.  A misbehaving service can be hard to remove in Windows.  It may require safe mode if the service won’t accept stop commands.
    4. Tweak Windows service settings.
      1. Open the Services management console (Administrative Tools -> Services).
      2. Edit the properties of the AutoSSH service.
      3. In the “Log On” tab, select the “This account” radio button and set the service to run as your current user.  This is very important to do before starting the service in order for the ssh certificate to be used.
      4. Change the startup mode to “Automatic (Delayed Start)”
      5. Start the service.
  2. Test your tunnel as described in 6.2 above
    1. Be sure to test after rebooting your target Windows 7 or 8.1 PC.
    2. I have had it working for 6months and used it a lot.  I’ve seen network drops.  Target PC reboots.   openSUSE server reboots.  The tunnel just keeps working.

If all went well, congratulations you now have a persistent tunnel

You should be aware you have just punched a hole through your firewall, so be sure and consider the security issues associated with that hole.  Many organizations require security beyond a simple login and password when connectivity is provided from outside the firewall.

How to promote your conference

April 11th, 2015 by

Local open source community is bigger now and next step for you is to organise (or join) global conferences. One part of the organisation is the promotion of the conference. You want to have as many visitors as you can.

I will try to write down what I did during openSUSE global conferences and some local events.

BEFORE THE EVENT

0. Web page

There MUST be a web page and a system that accepts registration, paper submission, information etc. Write everything that visitor should know about the conference.
We use OSEM in openSUSE. Check out https://events.opensuse.org

1. Blog blog blog.

You’ll have some announcements for the conference. Dates, the place, new website, call for papers announcement, hotels that visitors can stay, schedule, keynote speakers etc. Usually, every open source project has a central blog or news site. You can write the articles there. Try to make fuzz by publishing your articles often.
Global communities can translate the announcements to their language and promote the conference locally.

Local communities are formed by members with blogs who publish on different planet sites. You can make a schedule so everyone can publish the announcement every other day. More eyes will see the announcement and will apply either as speaker or visitor.

Two things you want to have is contributors+visitors and sponsors. If your project is famous, then it’s easy. If not, then you better publish the initial announcement to magazines, newspapers, technical blogs-sites. If you don’t have access, then you better send it by e-mail or fax and then call them and ask them if they got the text. If they publish it, you’re lucky.

Translate those announcements and publish them, so local population will see that there’s a conference coming.

2. Promote to other FOSS conferences

There are plenty of FOSS conferences around the world.
* Community (local or global) has to apply for a booth and/or, if it’s possible, present why someone should attend.
* At the booth, you should have promo materials of your conference and give away to local LUGs or hackerspaces to hang posters at their places.
* Another cool thing is to have free coupons for beer at the conference. If beer isn’t the solution, then find another thing that can be found only at your conference and give free coupons.
* Wear special T-Shirts with the logo or #oSC or “Ask me for the conference”. You show people that you’re organizing something and can ask you questions.
* Finally, go to other project’s booth and invite them. You can ask them if they want to have a booth at your conference or apply for a presentation.

3. Messages to post

Create a list of messages you’ll post to social media.
First of all, you should post the announcements.
Then create a list of general messages that you should post before the conference. Content will be related to the subject of the conference or the country etc.
When you have the schedule ready, create a post with the name of the person (mention him/her on the social media), the title of the presentation (mention if it’s a famous project).
The messages can be 2-3 per day but not the same time. Try to have 4-5 hours time delay between tweets.
(more…)

AMD Catalyst 15.3 Beta for openSUSE – new makerpm-amd-script is available

April 8th, 2015 by

AMD has released the new AMD Catalyst 15.3 Beta. They have not yet released a public beta driver for all other distributions. It is currently available for Ubuntu. *sigh* So, it is a bit hard work to implement this in the makerpm-amd-script to replace the latest AMD Catalyst 14.12 with AMD Catalyst 15.3 Beta. So do not confused if the script downloads the AMD Catalyst 14.12. 🙂

Unfortunately there is no release notes from AMD. This update can solve the issue with PowerXpress but I can not really verified this because lack of such hardware.

Another side note I have implemented a workaround in the script to get the driver works with the GNOME Displaymanager + GNOME. It is a little cruel hack but it works for the moment. Thanks to the user that they posted the article in my blog. 😉

For GNOME user with gdm: Execute the following command as root after the installation of the AMD driver and before restart the machine:
sh makerpm-amd-15.3-beta.sh --install-gdm-fix
If you update the AMD driver, so the workaround does not work anymore. It is important that you do not delete the file /amd_xversion and is needed for the workaround.

To revert the changes:
sh makerpm-amd-15.3-beta.sh --uninstall-gdm-fix

Before I forget it: All user from openSUSE Tumbleweed can also install the driver. But remember, Tumbleweed is under heavy development. I can not guarantee that the driver works in the future yet.

Downloads:

Installation guide (English):
http://en.opensuse.org/SDB:AMD_fglrx#Building_the_rpm_yourself

The above named installation guide is only for the stable driver but you can adapt it for the beta driver.

Bruno Friedmann will build the new RPM packages in the fglrx repository. Stay tune!

If you find any issue with the driver. Don’t hesitate to contact me. I am in contact with AMD and can forward your issue to the right place. Feedback are welcome.

A report of your system is very helpful beside your feedback. You can generate it with the script:
su -c 'sh makerpm-amd-15.3-beta.sh -ur'

Have a lot of fun!

Sebastian
openSUSE member / Official AMD Packaging Script Maintainer for openSUSE

German Blog: openSUSE – proprietären Grafik-Treiber AMD Catalyst 15.3 Beta als RPM installieren

UnReal World RPG and propiertary applications in linux ecosystem part SDL2 take 2

April 1st, 2015 by

My opinion is Simple Direct Layer 2  library is awesome piece of code. SDL2 delivers 99.9% what it promises. When SDL2 works it makes good habit to stay away your mind but now I want to talk about when SDL2 doesn’t work and when you want to deliver closed source application.

It seems that there is some problems with  OpenGL/DirectX and other accelerations APIs that they don’t play together without tweaking and researching ways to make them work. Okay this ain’t SDL2 fault completely this manufacturer problem again but.. you use SDL2 to get rid of hardware problems.

All those problems are solvable with current SDL2 version but again they takes lots of time and someone who is willing to debug application in non-working machine and remember this is normal stuff in development and not a big thing. But it’s big thing when you are about to releasing your new bling bling game with megalomanic blitting and your surfaces starts to blink every time you blit with some random machines. Even in not so bling bling UnReal Wolrd RPG you have problem with that but they are solved now but I builded many many Mac OS X and Linux builds before problem was traced to SDL2 related. If you are Apple people I point my finger to you. What the heck you are doing to openGL in Mac OS X??

SDL2 is what open source library but their biggest problems (in my opinion) are these: Hey Wiki is nice but have proper Doxygen or something documentation (which should be official), You have Bugzilla but there is no connection (or I just didn’t noticed) how bugs and Mercurial repository communicate each other and where/how you communicate with you users (mailinglists are so 90′ how about posting some news)?

What this leads is people post patches to Bugzilla where they get to nowhere and other one are using them because they solve their problem. This leads in situation where there is unofficial SDL2 libraries that are not compatible with each other. This is normal situation in open source world and SDL2 is under ZLib license so you can do it but what happens when they fix something that was broken to official SDL2 library and you using older one in development that is patched to work?

This is not SDL2 specific thing it’s very common situation with many open source projects (and yes they tend to have limited man power if you like to fix them you can! Learn to communicate with those people like I should with SDL2 people) but in a way SDL2 have deep connection with Valve (They use it in Linux steam client at least) and Steam ain’t small company they should but power behind this or let it go.

At the end remember this ain’t rant against SDL2 or SDL2 developers. They are doing hard work for you getting mostly nothing out of it. Because Eastern is all about pain and unhappiness so this was my contribution to that or no not really people!! Life is too short for sadness so have a lot’s of fun all eastern!