Prosody [1] is a lean XMPP (Extensible Messaging and Presence Protocol, formerly known as Jabber) server in Lua. It can speak IPv6, supports encrypted transport and – in the default configuration – very little else. You can, however, extend Prosody with modules to add virtually any kind of functionality you need. The number of modules is nearly into three figures [2].

Setting up a basic configuration is a two-step process: You need to create a user and then set up a domain. For my first steps on my home test network, I will be using example.com as the domain, but you can easily replace this with another domain when you go live. The following command sets up the user:

sudo prosodyctl adduser charly@example.com

You then need to add the account as the administrator to Prosody's central configuration file prosody.cfg.lua. The file typically resides below /etc/prosody/, but it can also live directly in /etc on older systems. The entry for this is:

admins = { "charly@example.com" }

If you like, you can define multiple admins.

Domains

The next step is to describe the example.com domain. You do this in older versions in prosody.cfg.lua, but most up-to-date Prosody systems store this in two separate directories: /etc/prosody/conf.avail and /etc/prosody/conf.d. You create the example.com.cfg.lua configuration file in /etc/prosody/conf.avail. Listing 1 shows that the file only contains a couple of lines.

The example.com dummy certificate normally comes free with your distribution, and you can replace it with a self-signed or purchased certificate later. To make sure that Prosody recognizes the new domain, I created a symlink to the configuration in the /etc/prosody/conf.d/ directory:

sudo ln -s /etc/prosody/conf.avail/example.com.cfg.lua /etc/prosody/conf.d/

After restarting the XMPP server by typing the following:

sudo service prosody restart

you can log in to the server as the administrator. If you then create a couple more user accounts, you can put on your reading glasses (if you need them) and start chatting right away!