Installing ejabberd

Currently there are a number of Open Source XMPP/Jabber server projects available with their own individual strengths and weaknesses. For this chapter, we're going to look at ejabberd, which is an extremely powerful and flexible option that has great online documentation. The code for ejabberd is written in Erlang, which is a language created for writing distributed, fault tolerant code. While we will not be taking advantage of the native clustering of ejabberd, it does exist for future expansion.

How to do it...

1. Install ejabberd through the following command:

   sudo apt-get install ejabberd
   

2. Restrict access to the authentication script:

   sudo chown root:ejabberd /usr/lib/ejabberd/priv/bin/epam
   sudo chmod 4750 /usr/lib/ejabberd/priv/bin/epam
   

3. Set up the PAM configuration:

   cat <<< '#%PAM-1.0
   auth        sufficient  pam_unix.so likeauth nullok nodelay
   account     sufficient  pam_unix.so' > /etc/pam.d/ejabberd
   

4. Set up /etc/ejabberd/ejabberd.cfg:

   {loglevel, 3}.
   
   {hosts...