EX294: Task, Play and Playbook

0 Basic idea

A task is a call to an ansible module.

A play contains one or more tasks against the same group of servers.

A playbook is a file that contains one or more plays.

1 ansible command can only run one task at once

When using the ansible command-line tool, you can only run one task.

$ ansible localhost -m command -a 'date'

Of course, you can write a script to run more tasks. like:

#!/bin/bash

ansible localhost -m command -a 'date'

ansible localhost -m copy -a 'src=test dest=/etc/test'

ansible localhost -m shell -a 'cat /etc/test'

Even though it works, Ansible provides a simpler and more powerful way ---- Playbook.

2 Run multiple tasks with ansible-playbook

A playbook is a file in YAML format. Below is an example.

# PLAY 1

- hosts: dbservers

  tasks:

          # TASK 1

          - name: install mysql

            command: touch /etc/mysql

# PLAY 2

- hosts: webservers

  become: yes

  become_method: su

  become_user: root

  tasks:

          # TASK 1

          - name: "ensure ~user01/.ssh exists"

            file:

                    path: ~user01/.ssh

                    state: directory

                    owner: user01

                    group: user01

                    mode: '0600'

          # TASK 2

          - name: create authorized_keys if it's not there

            file:

                    path: "~user01/.ssh/authorized_keys"

                    state: touch

                    owner: user01

                    group: user01

                    mode: '0600'

                    access_time: preserve

                    modification_time: preserve

In this playbook, there are 2 plays, while play1 has 1 task, play2 with 2 tasks.

In a task, besides module information, other information can be added to describe how to call the module.

In a play, besides tasks, other information can be added to describe how to run tasks.