This Docker images provides the ejabberd as an development image with the mDNS/ZeroConf stack on top. So you can enjoy the ejabberd service while it is accessible by default as ejabberd.local.

Heads up! This image is dedicated to your development environment. Do not run it on production!

• Requirements
• Getting starting
• docker-compose usage example
• Host configs
• Configure a different mDNS hostname
• Other top level domains
• Further reading

Requirements

• Host enabled Avahi daemon
• Host enabled mDNS NSS lookup

Getting starting

You just need to run it like that, to get a working ejabberd service:

$ docker run --rm hausgold/ejabberd

The port 5280 is proxied by haproxy to port 80 to make ejabberd.local directly accessible. So you can use the HTTP WebSockets (ejabberd.local/websocket) and Admin panel (ejabberd.local/admin) directly.

The admin user is admin@MDNS_HOSTNAME, so by default it is admin@ejabberd.local with the password defaultpw.

docker-compose usage example

services:
  ejabberd:
    image: hausgold/ejabberd
    environment:
      # Mind the .local suffix
      MDNS_HOSTNAME: ejabberd.test.local

Host configs

Install the nss-mdns package, enable and start the avahi-daemon.service. Then, edit the file /etc/nsswitch.conf and change the hosts line like this:

hosts: ... mdns4_minimal [NOTFOUND=return] resolve [!UNAVAIL=return] dns ...

Configure a different mDNS hostname

The magic environment variable is MDNS_HOSTNAME. Just pass it like that to your docker run command:

$ docker run --rm -e MDNS_HOSTNAME=something.else.local hausgold/ejabberd

This will result in something.else.local.

You can also configure multiple aliases (CNAME's) for your container by passing the MDNS_CNAMES environment variable. It will register all the comma separated domains as aliases for the container, next to the regular mDNS hostname.

$ docker run --rm \
  -e MDNS_HOSTNAME=something.else.local \
  -e MDNS_CNAMES=nothing.else.local,special.local \
  hausgold/ejabberd

This will result in something.else.local, nothing.else.local and special.local.

Other top level domains

By default .local is the default mDNS top level domain. This images does not force you to use it. But if you do not use the default .local top level domain, you need to configure your host avahi to accept it.

Further reading

• Docker/mDNS demo: https://github.com/Jack12816/docker-mdns
• Archlinux howto: https://wiki.archlinux.org/index.php/avahi
• Ubuntu/Debian howto: https://wiki.ubuntuusers.de/Avahi/