Module defaults

If you find yourself calling the same module repeatedly with the same arguments, it can be useful to define default arguments for that particular module using the module_defaults attribute.

Here is a basic example:

- hosts: localhost
  module_defaults:
    file:
      owner: root
      group: root
      mode: 0755
  tasks:
    - file:
        state: touch
        path: /tmp/file1
    - file:
        state: touch
        path: /tmp/file2
    - file:
        state: touch
        path: /tmp/file3

The module_defaults attribute can be used at the play, block, and task level. Any module arguments explicitly specified in a task will override any established default for that module argument:

- block:
    - debug:
        msg: "a different message"
  module_defaults:
    debug:
      msg: "a default message"

It’s also possible to remove any previously established defaults for a module by specifying an empty dict:

- file:
    state: touch
    path: /tmp/file1
  module_defaults:
    file: {}

Note

Any module defaults set at the play level (and block/task level when using include_role or import_role) will apply to any roles used, which may cause unexpected behavior in the role.

Here are some more realistic use cases for this feature.

Interacting with an API that requires auth:

- hosts: localhost
  module_defaults:
    uri:
      force_basic_auth: true
      user: some_user
      password: some_password
  tasks:
    - uri:
        url: http://some.api.host/v1/whatever1
    - uri:
        url: http://some.api.host/v1/whatever2
    - uri:
        url: http://some.api.host/v1/whatever3

Setting a default AWS region for specific EC2-related modules:

- hosts: localhost
  vars:
    my_region: us-west-2
  module_defaults:
    ec2:
      region: '{{ my_region }}'
    ec2_instance_facts:
      region: '{{ my_region }}'
    ec2_vpc_net_facts:
      region: '{{ my_region }}'