DevOps Classroomnotes 10/Apr/2022

Ansible-Controlling playbook execution

  • Forks:
    • Maximum number of simultaneous connections Ansible made on each Task
    • How to set it:
      • /etc/ansible/ansible.cfg
        [defaults]
        forks = 100
      • ansible-playbook -f 100 my_playbook.yml
        Preview
  • Strategy:
    • Types
      • linear
      • free
      • debug
    • How to set strategy
      • In playbook
        “`yaml
      • <li>hosts: all
        become: yes
        strategy: free
        “`

      • /etc/ansible/ansible.cfg
        [defaults]
        strategy = free

        Preview

Keywords that effect ansible playbook execution

  • serial:

    • if you want to manage only few machines at a time.
    • You can define how many hosts Ansible should manage at a single time by using the serial keywork
      “`yaml
    • </ul>
      <hr />
      <ul>
      <li>name: test
      hosts: all
      serial: 2
      gather_facts: no
      tasks:<ul>
      <li>name: first task
      debug:
      msg: "first task"</li>
      <li>name: second task
      debug:
      msg: "second task"
      “`

  • Let assume we have 4 nodes
    “`
    PLAY [all] ##################################</li>
    </ul>
    TASK [ first task] ##########################
    changed [web1]
    changed [web2]
    TASK [ second task] ##########################
    changed [web1]
    changed [web2]
    PLAY [all] ##################################
    TASK [ first task] ##########################
    changed [web3]
    changed [web4]
    TASK [ second task] ##########################
    changed [web3]
    changed [web4]
    “`
    * throttle: sets number of workers for a particular task. This can be set at block or task.
    * run_once: Runs only one node in the inventory
    * ignore_errors: ignores all the errors occured during playbook execution
    * ignore_unreachable: ignores unreachable nodes
    * order: Order in which nodes from inventory are picked
    Preview

Ansible Tower Installation

  • Refer Here
  • For ansible tower installation and usage please refer classroom video

Ansible Vault

  • Ansible Vault helps secure vital secret information.
  • Ansible vault can encrypt variables or even entire files and YAML Playbooks
  • Create an encrypted file in Ansible
    • Create a file with username: tomcat and password: tomcat in yaml
      Preview
  • view the encrypted file
    Preview
  • edit the content
    Preview
  • if you want to change the password for the file
    Preview
  • Encrypting existing files using vault
    Preview
  • Decryption of the encrypted file
    Preview

Preview

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