In Ansible, there are three types of Special Variables.

• Connection Variables (this article)
• Magic Variables
• Facts

By default, modules are run against your managed nodes (the target systems). The connection plugin with can be used to run a module on the control node (that's your Ansible server). Refer to these articles for a better understanding of how tasks are run against the control node or managed nodes.

• Run tasks on the control node
• Run tasks on your managed nodes

In this example, the connection plugin is used to run every task in the playbook against the control node.

---
- hosts: all
  connection: local
  tasks:
    - name: remove foo.txt on control node
        file:
        path: /tmp/foo.txt
        state: absent

Or, the --connection command line flag could be used.

ansible-playbook foo.yml --connection="local 127.0.0.1"

Often, run_once parameter is used so that each task in the playbook is only ran one time on the control node.

---
- hosts: all
  connection: local
  tasks:
    - name: remove foo.txt on control node
        file:
        path: /tmp/foo.txt
        state: absent
        run_once: true

Roles

All of the tasks in a particular role can be performed on the control node. In this example, every task in the "foo" role will be performed on the control node.

Or like this.

---
- hosts: all
  roles:
    - role: foo
      connection: local