Ansible PlayBook - Task

About

A task is a call to an ansible module with arguments located in a play list. Variables can be used in arguments to modules.

Tasks are executed top to bottom one at a time, against

all machines

matched by the host pattern before moving on to the next task.

Task should be idempotent in order to be able to re-run the playbook safely. (ie check whether the desired final state has already been achieved, and if that's the case exit without performing any actions).

Format

module: options
# or
action: module options

ie example

template:
    src: templates/foo.j2
    dest: /etc/foo.conf
# or
action: template src=templates/foo.j2 dest=/etc/foo.conf

Management

Omit parameters

- name: touch files with an optional mode
  file: dest={{ item.path }} state=touch mode={{ item.mode | default(omit) }}
  loop:
    - path: /tmp/foo
    - path: /tmp/bar
    - path: /tmp/baz
      mode: "0444"

Status

See Ansible - Task Status

Import vs Include

See What's the difference between Import vs Include in Ansible?

Execution

- command: /opt/application/upgrade_db.py
  run_once: true
  delegate_to: web01.example.org

where:

run-once - only run a task one time for a batch of hosts
delegate_to specify an individual host to execute on

Example

---
- hosts: webservers 
  remote_user: root 
  tasks:
    - name: First task -  A command execution
      command: /sbin/setenforce 1
      remote_user: yourname
      become: yes
      become_method: sudo # or su
      ignore_errors: True # Ignore the exit code
      vars: # To define system variables
         ansible_become: yes
         ansible_become_method: runas
         ansible_become_user: DOMAIN\user
         ansible_become_pass: Password01
         ansible_become_flags: logon_type=new_credentials logon_flags=netcredentials_only
    - name: template configuration file with var  {{ myVar }} that restart services only if the file change
      template:
        src: template.j2
        dest: /etc/httpd/conf.d/{{ myVar }}
      notify: 
        - restart memcached
        - restart apache

where:

name is the task name (default to 'action')
remote_user define the running user
become defines privileges escalation (ie Security - (Proxy|N-tier|Impersonation) authentication). Connection variables in inventory
- ansible_become
- ansible_become_method
- ansible_become_user
- ansible_become_pass
notify call handlers.
when conditional. See Ansible - When
vars can set built in variable