Ansible- 10 handler

[oracle@oel01db playbooks]$ cat nginx

---

- name: Install and configure Nginx using yum

  hosts: webservers

  gather_facts: no

  become: yes               # elevate to root

  become_user: root         # optional (default = root)

  tasks:

    - name: Install Nginx using yum

      yum:

        name: nginx

        state: latest

    - name: Copy index.html

      template:

        src: index.html

        dest: /usr/share/nginx/html/index.html

        owner: nginx

        group: nginx

        mode: '0644'

    - name: Copy updated.html

      template:

        src: updated.html

        dest: /usr/share/nginx/html/index.html

        owner: nginx

        group: nginx

        mode: '0644'

      notify:

        - Restart Nginx

  handlers:

    - name: Restart Nginx

      service:

        name: nginx

        state: restarted

[oracle@oel01db playbooks]$

✅ 1. Do handlers run only when a task changes?

Yes.
Handlers run only when a task notifies them, and a task notifies only when:

✔ The task reports changed: true
❌ Not when ok: true
❌ Not when skipped
❌ Not when failed

notify:

  - Restart Nginx

This handler will run only when the template task actually changes the file.

.

---

🧪 Example

First run

updated.html is copied (file content changes) → task changes → handler runs → Nginx restarts

Second run

File content is same, no changes → changed: false → handler will NOT run

Ansible handler runs ONLY if the task with notify changes.

Task 3 (Copy updated.html)

This one has:

notify:
  - Restart Nginx

So only this task can trigger the handler.