4.4 - Ansible-Pull

In this lab we’ll have a short glimpse at how ansible-pull works.

Task 1

  • Search docs.ansible.com for information about the ansible-pull command.
  • Look for a way to execute a playbook using ansible-pull
  • Search for a example playbook

Task 2

On node1:

  • Install all needed packages to use ansible-pull
  • Use an ansible-pull command that uses the resources in the folder resources/ansible-pull/ of our github repository located at https://github.com/puzzle/ansible-techlab. This command should do the following:
  • Apply the playbook local.yml located at the resource/ansible-pull folder and run it on all hosts in the inventory file hosts
  • Show the content of /etc/motd and verify, that the file was copied using ansible-pull
  • Also verify, that no content of the git repository was copied to the local folder.

Note the following:

  • If no playbook is specified, ansible-pull looks for a playbook local.yml.
  • The location of files given as paratmeters to the ansibel-pull command ar always relative to the top level of the git repository.
  • All information to run the ansible-pull command is taken from the git repository (playbook, inventory, MOTD-file to be copied). No local configuration is used!

Task 3

It’s a best practice to use cronjobs to trigger ansible-pull run at a regular basis. Do the following on node1:

  • Create a cronjob /etc/cron.d/ansible-pull. This cronjob should run every minute as user root the ansible-pull commant from Task 2.
  • Now remove the existing /etc/motd file and use the command watch to show the content of /etc/motd every second. We want to observe that our cronjob runs the ansible-pull command again and restore the previously deleted MOTD-file

Task 4

This task has nothing to do with ansible-pull, we just clean up the ansible-pull configurations. Create a playbook revert_motd.yml that runs on node1. It should:

  • uninstall ansible
  • remove the cronjob /etc/cron.d/ansible-pull
  • empty the file /etc/motd

Run the playbook.

Solutions

$ sudo yum install -y ansible
$ /usr/bin/ansible-pull -U https://github.com/puzzle/ansible-techlab -i resources/ansible-pull/hosts resources/ansible-pull/local.yml
$ cat /etc/motd
$ ll #no file here...

$ sudo vim /etc/cron.d/ansible-pull #create the file with the content ->
$ cat /etc/cron.d/ansible-pull 
* * * * * ansible /usr/bin/ansible-pull -U https://github.com/puzzle/ansible-techlab -i resources/ansible-pull/hosts resources/ansible-pull/local.yml
$ sudo rm -f /etc/motd; watch cat /etc/motd

$ cat revert_motd.yml
---
- hosts: node1
  become: yes
  tasks:
    - name: uninstall ansible
      yum:
        name: ansible
        state: absent
    - name: ensure cronjob not present
      file:
        path: /etc/cron.d/ansible-pull
        state: absent
    - name: ensure MOTD file empty
      copy:
        content: ""
        dest: /etc/motd

$ ansible-playbook revert_motd.yml