How to pass variables to local_action module in Ansible?

Passing Variables to local_action Module in Ansible

In Ansible, the local_action module allows you to execute tasks on the control node (the machine running the Ansible playbook) instead of the remote hosts. When using the local_action module, you may need to pass variables to the tasks being executed on the control node. Here's how you can do that:

Using Registered Variables

One way to pass variables to the local_action module is by using registered variables. When you run a task in Ansible, you can store the output of that task in a variable using the register keyword. You can then use this registered variable in the local_action module.

Here's an example:

- name: Get the current working directory
  command: pwd
  register: current_dir

- name: Print the current working directory
  local_action:
    module: debug
    msg: "The current working directory is {{ current_dir.stdout }}"

In this example, the command module is used to get the current working directory, and the output is stored in the current_dir variable. The local_action module then uses the current_dir.stdout variable to print the current working directory.

Using Playbook Variables

You can also pass variables directly to the local_action module by defining them in the playbook. These variables can be defined at the play level or the task level, depending on your needs.

Here's an example:

- hosts: localhost
  vars:
    my_variable: "Hello, World!"

  tasks:
    - name: Print the variable
      local_action:
        module: debug
        msg: "The value of my_variable is {{ my_variable }}"

In this example, the my_variable is defined at the play level and is then used in the local_action module to print its value.

Using Extra-vars

Another way to pass variables to the local_action module is by using the --extra-vars (or -e) option when running the Ansible playbook. This allows you to pass variables from the command line or through a JSON or YAML file.

Here's an example:

ansible-playbook my_playbook.yml -e "my_variable=Hello, World!"

In this example, the my_variable is passed as an extra variable to the playbook, and it can then be used in the local_action module.

Mermaid Diagram

Here's a Mermaid diagram that illustrates the different ways to pass variables to the local_action module in Ansible:

graph TD A[Passing Variables to local_action Module] B[Registered Variables] C[Playbook Variables] D[Extra-vars] A --> B A --> C A --> D B --> E[Register Task Output] C --> F[Define Variables in Playbook] D --> G[Pass Variables from Command Line]

By using these different methods, you can effectively pass variables to the local_action module in your Ansible playbooks, allowing you to customize the behavior of tasks running on the control node.