The Ansible Agent is a simple daemon used as a transport for Ansible.
Ansible traditionally operates over the SSH daemon that is installed on all machines that are remotely configured. In general, the SSH daemon and ControlMaster are good enough for most workflows. Using the SSH daemon makes starting to use Ansible much easier.
On the other hand, using SSH and ControlMaster can be unreliable transports. On certain platforms, like Ubuntu, are unusable because the SSH daemon will randomly exit with exit status 0 and cause random tasks to fail (example).
When you manage an entire platform with Ansible, owning and configuring the machines, then being agentless doesn't really matter. As long as the agent is easy to install, it's trivial to install one either embedded in the launched image or by just using Ansible to download a binary and start it.
To install the daemon, copy the binary to the machine and start it. See the configuration section below for customizing the daemon.
To have Ansible connect to the agent, copy the file in
connection_plugins/agent.py to the connection plugins folder in your
Ansible repository. Set the following setting in your ansible.cfg
file.
[defaults]
transport = agent
You can also configure the connection type in the playbook by doing:
---
- hosts: all
connection: agent
tasks:
- name: print a greeting message
comand: echo "Hello, World!"
The server configuration file is in toml. A sample configuration is
provided in conf/defaults.toml.