ansible playbook when

`ansible playbook when` is a conditional statement used in Ansible playbooks to define when a particular task or role should be executed. It allows you to specify conditions based on variables or facts gathered from the target hosts.

Here's an example of how `when` can be used in an Ansible playbook:

- name: Example playbook
  hosts: web_servers
  tasks:
    - name: Install Apache web server
      package:
        name: apache2
        state: present
      when: ansible_distribution == "Ubuntu"

In this example, the task to install Apache web server will only be executed if the target host's distribution is Ubuntu. The condition `ansible_distribution == "Ubuntu"` is evaluated, and if it's true, the task is executed; otherwise, it is skipped.

You can use various operators and comparison expressions in the `when` statement to define more complex conditions. Ansible provides a rich set of built-in variables and facts that can be used for condition evaluation.