Lookups

Lookup plugins retrieve data from outside sources such as files, databases, key/value stores, APIs, and other services. Like all templating, lookups execute and are evaluated on the Ansible control machine. Ansible makes the data returned by a lookup plugin available using the standard templating system. Before Ansible 2.5, lookups were mostly used indirectly in with_<lookup> constructs for looping. Starting with Ansible 2.5, lookups are used more explicitly as part of Jinja2 expressions fed into the loop keyword.

Using lookups in variables

You can populate variables using lookups. Ansible evaluates the value each time it is executed in a task (or template):

vars:
  motd_value: "{{ lookup('file', '/etc/motd') }}"
tasks:
  - debug:
      msg: "motd value is {{ motd_value }}"

For more details and a list of lookup plugins in ansible-core, see Working With Plugins. You may also find lookup plugins in collections. You can review a list of lookup plugins installed on your control machine with the command ansible-doc -l -t lookup.