Module defaults

If you frequently call the same module with the same arguments, it can be useful to define default arguments for that particular module using the module_defaults keyword.

Here is a basic example:

- hosts: localhost
  module_defaults:
    ansible.builtin.file:
      owner: root
      group: root
      mode: 0755
  tasks:
    - name: Create file1
      ansible.builtin.file:
        state: touch
        path: /tmp/file1

    - name: Create file2
      ansible.builtin.file:
        state: touch
        path: /tmp/file2

    - name: Create file3
      ansible.builtin.file:
        state: touch
        path: /tmp/file3

The module_defaults keyword 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:
    - name: Print a message
      ansible.builtin.debug:
        msg: "Different message"
  module_defaults:
    ansible.builtin.debug:
      msg: "Default message"

You can remove any previously established defaults for a module by specifying an empty dict:

- name: Create file1
  ansible.builtin.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:
    ansible.builtin.uri:
      force_basic_auth: true
      user: some_user
      password: some_password
  tasks:
    - name: Interact with a web service
      ansible.builtin.uri:
        url: http://some.api.host/v1/whatever1

    - name: Interact with a web service
      ansible.builtin.uri:
        url: http://some.api.host/v1/whatever2

    - name: Interact with a web service
      ansible.builtin.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:
    amazon.aws.ec2:
      region: '{{ my_region }}'
    community.aws.ec2_instance_info:
      region: '{{ my_region }}'
    amazon.aws.ec2_vpc_net_info:
      region: '{{ my_region }}'

Module defaults groups

New in version 2.7.

Ansible 2.7 adds a preview-status feature to group together modules that share common sets of parameters. This makes it easier to author playbooks making heavy use of API-based modules such as cloud modules.

Group

Purpose

Ansible Version

aws

Amazon Web Services

2.7

azure

Azure

2.7

gcp

Google Cloud Platform

2.7

k8s

Kubernetes

2.8

os

OpenStack

2.8

acme

ACME

2.10

docker*

Docker

2.10

ovirt

oVirt

2.10

vmware

VMware

2.10

  • The docker_stack module is not included in the docker defaults group.

Use the groups with module_defaults by prefixing the group name with group/ - for example group/aws.

In a playbook, you can set module defaults for whole groups of modules, such as setting a common AWS region.

# example_play.yml
- hosts: localhost
  module_defaults:
    group/aws:
      region: us-west-2
  tasks:
  - name: Get info
    aws_s3_bucket_info:

  # now the region is shared between both info modules

  - name: Get info
    ec2_ami_info:
      filters:
        name: 'RHEL*7.5*'

In ansible-core 2.12, collections can define their own groups in the meta/runtime.yml file. module_defaults does not take the collections keyword into account, so the fully qualified group name must be used for new groups in module_defaults.

Here is an example runtime.yml file for a collection and a sample playbook using the group.

# collections/ansible_collections/ns/coll/meta/runtime.yml
action_groups:
  groupname:
    - module
    - another.collection.module
- hosts: localhost
  module_defaults:
    group/ns.coll.groupname:
      option_name: option_value
  tasks:
    - ns.coll.module:
    - another.collection.module