Use changed_when to mark when a task changes the system

Short answer

Use changed_when to report changed only when the task actually changed the system.

Request

mark a command task as changed only when stdout contains created

Example

A quick heads-up: Every environment is different. Review and test this example before you run it on systems you care about.

---
- name: Demonstrate changed_when
  hosts: localhost
  gather_facts: false
  connection: local

  tasks:
    - name: Run a command and register output
      ansible.builtin.command:
        cmd: echo "status=created"
      register: cmd_result
      changed_when: "'created' in cmd_result.stdout"
      failed_when: false

How it works

Many command modules report changed on every run. Use changed_when so handlers and reports reflect real change.

When to use it

• Preventing unnecessary handler runs
• Accurate change reporting for CLI tools

Requirements

• Ansible: >=2.14

Validation

• Syntax validated
• Not execution-tested
• Last verified 2026-09-03