[Wiki] Ansible cheatsheet

Ansible Infos

Directory Structure:

• ansible.cfg: General configuration file
• playbook.yml: Playbook file (YAML)
• group_vars: Directory for group variables YAML files
• host_vars: Directory for host variables YAML files
• inventory.yml: Host inventory file (YAML)
• templates: Directory for Jinja2 templates

Troubleshooting:

• Test connection to hosts in inventory group: command: ansible routers -m ping -i inventory.yml
• List modules in a collection: command: ansible-doc -l | grep cisco.ios
• Display documentation for a module: command: ansible-doc ios_bgp

Inventory:

  - group_A:
      children:
        subgroup_A:
          hosts:
            host_1:
              ansible_host: 192.168.1.2
            host_2:
              ansible_host: 192.168.1.3
            host_3:
              ansible_host: 192.168.1.4

Graphical view of inventory:

command: ansible-inventory –graph -i inventory.yml

Complete list of hosts in inventory with their variables:

command: ansible-inventory –list -i inventory.yml

View details of a host:

command: ansible-inventory –host R1

Playbook:

• Run a playbook: command: ansible-playbook playbook.yml
• Launch options: -i: Choose inventory file -C: Perform a check (no changes made) -M: Specify the module -c: Specify connection type -u: Specify the user -k: Specify the password -e: Provide a variables file –list-hosts: See targeted hosts (no changes made) –ask-vault-password: Prompt for vault password

Variables:

Connection:

ansible_connection: local or network_cli
ansible_network_os: platform (Cisco -> ios)
ansible_user: SSH username
ansible_ssh_pass: SSH password
ansible_ssh_private_key_file: SSH key file

Execution:

ansible_command_timeout: execution timeout in seconds
ansible_become: privilege escalation (yes or no)
ansible_become_method: enable

Filters:

• Convert compatible data to JSON or YAML: example: “{{ output | to_json }}” “{{ output | to_yaml }}”
• Parse command output with a textfsm template: example: “{{ output | ansible.netcommon.parse_cli_textfsm(‘template’) }}”
• Find a regex pattern match: example: “{{ output | regex_search(‘[\d\w]{4}.[\d\D]{4}.[\d\D]{4}’) }}”
• List all occurrences of a regex pattern: example: “{{ output | regex_findall(‘GigabitEthernet0\/0\/[0-9]{1,2}’) }}”

Common regex patterns:

.: match any single character
^: match beginning of string
$: match end of string
|: equivalent to OR
[]: match any character in set
[^ ]: match any character not in set
(): capture group
{n}: match exactly n occurrences
\s: match whitespace
\d: match digit
\w: match word character

Modules:

#### ios_config:

    - name: top level configuration
      ios_config:
        lines: hostname my_device

    - name: configure interface 
      ios_config:
        lines:
          - description LAN
          - ip address 192.168.1.254 255.255.255.0
        parents: interface GigabitEthernet0/0

    - name: save running to startup when modified
      ios_config:
        save_when: modified

#### ios_command:

    - name: run commands
      ios_command:
        commands:
          - show version
          - show vlans

#### li_parse:

    - name: run command and parse with ntc_templates
      ansible.utils.cli_parse:
        command: "show version"
        parser:
          name: ansible.netcommon.ntc_templates
      register: output

#### debug:

    - name: display result
      debug:
        msg: "{{ output }}