Marathon role for Ansible with optional HAProxy configuration support. Marathon is installed with HA mode activated (see command line options).

• Ansible-Java, or Java installed on the host machine
• HAProxy installed for HAProxy support.

See vars/main.yml for a full list. The most important settings are:

• zookeeper_hostnames: "localhost:2181" The path to Zookeeper which Marathon can use to find the Mesos masters and use as a state store.
• mesos_zookeeper_path: "/mesos" The path to Mesos in the Zookeeper cluster
• marathon_zookeeper_path: "/marathon" The path to Marathon in the Zookeeper cluster
• haproxy_script_location: "/usr/local/bin" The path to install the haproxy configuration script. If this is an empty string "" haproxy configuration will be disabled.

A cron job is configured to run the haproxy_dns_cfg script which will query the marathon api for applications and setup the appropriate frontend (listening on port 80) with backends for each application. HAProxy will look for a hostname prefixed with the application name and route to that backend. Using this technique you can wildcard a dns host to all your masters (say, *.example.com) and an application you launch (say, "myapp") will be available at myapp.example.com.

This can be disabled by setting the haproxy_script_location to an emptry string "". It will only be installed if HAProxy is present.