Notes on ScopePort

I am planning to create a ScopePort screencast soon. I had no experience with screencasts when I started to work on that topic. This is why I encountered two main problems:

• How do I create the video?
• How do I add sound to that video?

The first problem was solved easily. I tried a few screen recorders and decided to use recordmydesktop. The main advantage of recordmydesktop is that it captures everything in a raw mode and encodes it when you stop recording. That makes it possible to record your screen without bigger speed problems. Everything looks pretty smooth and is usable for a screencast.

The second problem cost me a lot of Google searching. How can I add sound to that video? Here is the way I finally used:

First step: Capture the video

No Problem. I started recordmydesktop with the following parameters to capture only the first screen, with a fake cursor (the original one from KDE4 caused some problems) and with no sound. The sleep 3 before the execution of recordmydesktop gives me some time to close the shell and get ready to record.

sleep 3 && recordmydesktop -width 1680 -height 1050 -dummy-cursor black --no-sound

Second step: Convert the captured video to AVI

The file recordmydesktop creates is in a OGG format. That is usually fine but we require an AVI file to add the sound. I converted the OGG file to AVI with mencoder (Usually available in your favorite repository):

mencoder -idx screencast.ogg -ovc lavc -oac mp3lame -o screencast.avi

Third and last step: Add the audio

Now we can edit the video file with avidemux (also usually available in your repositories). Select “Audio” -> “Main Track”.

Now select a AC3, MP3 or WAV file that should be added as the main audio track. Press okay, select “File” -> “Save” -> “Save video” and you are done. That’s it.

Sven Kinne – who has been involved in a lot of alpha testing – just sent me an account for his ScopePort installation. He monitors around 50 services on different hosts. Here is a screenshot:

We are always happy about screnshots of your ScopePort installations! Send them to lennart@scopeport.org.

You can now install the latest version of the ScopePort client via Rubygems. The gem is hosted at GitHub so you have to add GitHub as a repository first:

root@sundaysister# gem sources -a http://gems.github.com

You can now install the ScopePort client:

root@sundaysister# gem install lennartkoopmann-scopeport-client-ruby

Just start the client with “scopeport-client” if the gem binaries are in your $PATH.

Note that the current client version can only connect to a ScopePort server. It does not send real sensor data yet.

I just pushed a first ScopePort sample client to our repositories. It is written in Ruby, connects to a ScopePort server, logs in and sends a sample sensor data package.

See the source code here: http://github.com/lennartkoopmann/scopeport-client-ruby/blob/665e4d69a93c73fd8055511aae55e88afcfb42c2/scopeport-client.rb

The ScopePort protocol for logging in and sending sensor data is described here: http://scopeport.org/docs/host_communications

Hey, by the way: ScopePort is now on Twitter!

Greg Pollack created a 34 minutes video that shows the RailsConf 2009 speakers.

I just relaunched the whole blog. There is a new layout, a lot of fixes and a completely updated WordPress including all plugins.

Meanwhile the ScopePort development is proceeding in big steps. I am currently hacking on a cluster model and a refactoring of the host monitoring parts. Ernesto is doing great work on the web interface. So stay tuned – We are going towards the first packaged release!

I had this problem for a longer time now: When I established a VPN connection on Ubuntu Intrepid it just failed after a few seconds or minutes. This did not happen in the earlier Ubuntu versions.

The error in the syslog was: “nm-pptp-service-9656 warn[decaps_gre:pptp_gre.c:331]: short read (-1): Message too long”

There is a very simple solution for that: Just set the MTU of your VPN connection to 1412 and the connection should stay alive! (sudo ifconfig ppp0 mtu 1412)

I recently released the new ScopePort website! Check it out: http://www.scopeport.org/

Please let me know what you think about it.

You try to initialize a git repository with “git init” and get an error reply like:

git: ‘init’ is not a git-command

This happened to me on Debian Etch. You simply have a too old version of git! Uninstall your version (e.g. aptitude purge git) and download the current version from the git website.

I have been searching for a good GNOME LaTeX editor for a long time after i switched from KDE to GNOME. (My KDE favorite was Kile). I tested some andcame to the result that Texmaker is the best LaTeX editor that does not require the KDE libraries (even though it is based on QT)

Writing LaTeX with vim is also okay but I like to just press F6 and get the generated PDF file opened in my favorite PDF viewer.