The Datadog.datadog role maintained by Datadog is great, but it does not attempt to configure monitored services for monitoring, and in order to have it configure multiple integrations, you would either have to duplicate your configs a lot, or do tricky things with Ansible variables which you shouldn't be doing and aren't worth your time.
This role provides an alternate way to setup a target machine and its Datadog agent to monitor Varnish.
It is strongly recommended that the Datadog.datadog role is used to install the agent.
With the agent installed, this role may be run with become if everything is default (at least on ubuntu 14.04).
The datadog agent's username and group may be configured, as well as the integration's tags as well as the entire config.
Consult this role's defaults for variables names.