Advanced Task Management | Tasks And Handlers

Introduction

In this tutorial, we will explore advanced task management techniques in Ansible. Task management is crucial for automating complex workflows and ensuring that tasks are executed in a controlled manner. We will cover topics such as task delegation, conditionals, loops, and handlers.

Task Delegation

Task delegation allows you to execute a task on a different host than the one specified in the play. This can be useful when you need to execute a task on a control machine or a specific server.

Example of task delegation:

- name: Run command on a different server
  command: /usr/bin/do_something
  delegate_to: server2.example.com

Conditionals

Conditionals in Ansible allow you to execute tasks based on certain conditions. This is done using the when keyword.

Example of using conditionals:

- name: Install httpd if it's not already installed
  yum:
    name: httpd
    state: present
  when: ansible_facts['os_family'] == "RedHat"

Loops

Loops allow you to repeat a task multiple times with different items. Ansible provides various looping methods such as with_items, with_dict, and with_fileglob.

Example of using loops:

- name: Install multiple packages
  yum:
    name: "{{ item }}"
    state: present
  with_items:
    - httpd
    - vim
    - git

Handlers

Handlers are special tasks that are triggered by other tasks using the notify keyword. Handlers are typically used to restart services after configuration changes.

Example of using handlers:

- name: Install httpd
  yum:
    name: httpd
    state: present
  notify: Restart httpd

handlers:
  - name: Restart httpd
    service:
      name: httpd
      state: restarted

Advanced Handlers

In more advanced scenarios, handlers can be used with conditionals and loops. This allows for complex workflows where multiple conditions and actions are handled efficiently.

Example of advanced handlers:

- name: Install multiple packages
  yum:
    name: "{{ item }}"
    state: present
  with_items:
    - httpd
    - vim
    - git
  notify:
    - Restart httpd
    - Restart sshd

handlers:
  - name: Restart httpd
    service:
      name: httpd
      state: restarted

  - name: Restart sshd
    service:
      name: sshd
      state: restarted

Conclusion

In this tutorial, we have covered advanced task management techniques in Ansible, including task delegation, conditionals, loops, and handlers. These features allow you to create more flexible and powerful automation workflows. By mastering these techniques, you can significantly enhance your Ansible playbooks and automate complex tasks with ease.

Advanced Task Management in Ansible