Sunday, December 21, 2008

Installing Skype on an XO laptop

I successfully installed Skype with video and did a test call from my XO laptop (build 720) today. I used a version of these instructions. Note: Skype will probably need to be reinstalled each time the xo laptop is upgraded. Warning: Skype isn't really meant for the xo - this install creates several zombie processes each time Skype is started, and the sound quality is definitely inferior.

  1. Install Skype
    $su
    #mkdir /home/olpc/skype
    #cd skype
    #wget http://skype.com/go/getskype-linux-fc7
    #yum --nogpgcheck -y localinstall skype-2.0.0.72-fc5.i586.rpm
    #wget ftp://ftp.pbone.net/mirror/atrpms.net/el5-i386/atrpms/testing/#libasound2-1.0.15-33.el5.i386.rpm
    #rpm -i libasound2-1.0.15-33.el5.i386.rpm
    #wget http://dev.laptop.org/~ffm/gstfakevideo.zip
    #unzip gstfakevideo.zip
    #chmod +x gstfakevideo
    
  2. Skype doesn't have a sugar package, so it must be started by root with the command /home/olpc/skype/gstfakevideo. This is cumbersome and hard to remember, so use nano .bashrc to create an alias. Add this line to the 'alias' section of the .bashrc.
    # User specific aliases and functions
    alias skype 'sudo /home/olpc/skype/gstfakevideo'
    
    Now the user (not root) can start Skype from any prompt with the command skype.

SSH suddenly stops working

I tried to ssh to my XO laptop today, but got the following error:

me:~$ssh user@(IP addr of xo_laptop)
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
blah:blah:blah:blah:blah:blah:blah:blah:blah:blah.
Please contact your system administrator.
Add correct host key in /home/USER/.ssh/known_hosts to get rid of this message.
Offending key in /home/USER/.ssh/known_hosts:NUMBER
RSA host key for (IP addr of xo_laptop) has changed and you have requested strict checking.
Host key verification failed.
me:~$

Why? Probably because I upgraded the OLPC laptop.

How to fix it?

  1. Use ssh-keygen -R (IP addr) to purge the old key.
  2. Connect again like normal ssh user@xo_laptop to install the new (current) key.