Ansible Journey 9: Tags

Ansible tags allow you to run specific portions of your playbook, ignoring others. Since each invocation of ansible-playbook against a playbook requires multiple checks to determine whether or not a play should attempt to exectue, running an entire playbook will require more time than just running a portion of that playbook. Tags allow us to target a specific play or task. This can save significant time, particularly during testing, which may result in numerous executions to test individual changes.

We specify tags using the ‘tags’ directive:

tags: tag_1,tag_2...

To see what tags have been applied to a playbook, use ansible-playbook’s ‘--tags’ paraameter:

ansible-playbook --tags web --ask-become-pass playbooks/site.yml

or

ansible-playbook --tags “web,db” --ask-become-pass playbooks/site.yml

Here are two sections of our site.yaml playbook that apply tags:

- hosts: all
  become: true
  pre_tasks:

  - name: Install Updates - Rocky
    tags: always
    dnf:
      update_only: true
      update_cache: true
[...]

 - hosts: web_servers
  become: true
  tasks:

  - name: Install Nginx Web Service
    tags: nginx,rocky,web
    dnf:
      name:
        - nginx
        - pcp-pmda-nginx
      state: latest
    when: ansible_distribution == "Rocky"

The 'always' tag is a special tag that instructs Ansible to always run a play or task, regardless of whether it is specified. It has a complement, "never." These can both be overridden with "--skip-tags."

 

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