Red Hat Ansible for Network Automation

Use individual ad hoc commands to view the host name, domain, and name servers for spine01, which is a VyOS device.

[student@workstation proj]$ ansible -m vyos_command \
>  -a "commands='sh host name'" spine01
[student@workstation proj]$ ansible -m vyos_command \
> -a "commands='sh host domain'" spine01
[student@workstation proj]$ ansible -m vyos_command \
> -a "commands='sh dns forwarding nameservers'" spine01

Use individual ad hoc commands to view the host name, domain, and name servers for cs01, which is an IOS device.

[student@workstation proj]$ ansible -m ios_command \
> -a "commands='sh run | include hostname'" cs01
[student@workstation proj]$ ansible -m ios_command \
> -a "commands='sh run | include ip domain name'" cs01
[student@workstation proj]$ ansible -m ios_command \
> -a "commands='sh run | include ip name-server'" cs01

Compose a playbook named host-dnsinfo1.yml that displays the host name, domain name, and name servers for cs01.

[student@workstation proj]$ cat host-dnsinfo1.yml
---
- name: display host name, domain name, nameservers for ios devices
  hosts: ios

  tasks:

  - name: run the commands
    ios_command:
      commands:
      - sh run | include hostname
      - sh run | include ip domain name
      - sh run | include ip name-server
    register: result

  - debug:
      var: result.stdout

Alternatively, you could define a variable of type sequence that contains the distinctive portion of the show run | include commands, and loop over that.

[student@workstation proj]$ cat host-dnsinfo1.yml
---
- name: display host name, domain name, nameservers for ios devices
  hosts: ios
  vars:
    includes:
      - hostname
      - domain name
      - name-server

  tasks:

  - name: run the commands
    ios_command:
      commands:
      - sh run | include {{ item }}
    loop: "{{ includes }}"
    register: result

  - debug:
      var: item.stdout
    loop: "{{ result.results }}"

Perform the play in the playbook you just created.

[student@workstation proj]$ ansible-playbook host-dnsinfo1.yml

PLAY [display host name, domain name, nameservers for ios devices] *************

TASK [run the commands] ********************************************************
ok: [cs01]

TASK [debug] *******************************************************************
ok: [cs01] => {
    "result.stdout": [
        "hostname cs01",
        "ip domain name lab.example.com",
        ""
    ]
}

PLAY RECAP *********************************************************************
cs01                      : ok=2   changed=0   unreachable=0   failed=0

Compose a playbook named multi-vendor-host-dnsinfo1.yml that displays the host name, domain name, and name servers for both VyOS and IOS devices, and which defaults to hosts group network, and can target an individual host when the ansible-playbook command is used to set the variable target with the -e option.

You can copy the playbook from step 3 to save typing.

[student@workstation proj]$ cat multi-vendor-host-dnsinfo1.yml
---
- name: multi-vendor play to display host name, domain name, nameservers
  hosts: network

  tasks:

  - name: ios host, domain, nameserver
    ios_command:
      commands:
        - sh run | include hostname
        - sh run | include ip domain name
        - sh run | include ip name-server
    register: result
    when: ansible_network_os == 'ios'

  - name: display ios host settings
    debug:
      var: result.stdout
    when: ansible_network_os == 'ios'

  - name: vyos host, domain, nameserver
    vyos_command:
      commands:
        - sh host name
        - sh host domain
        - sh config | grep name-server
    register: result
    when: ansible_network_os == 'vyos'

  - name: display vyos host settings
    debug:
      var: result.stdout
    when: ansible_network_os == 'vyos'

Note that the same alternative approach with loops can also be employed here.

Perform the play contained in your new playbook. First use the limit option (-l SUBSET) to specify cs01, then run it in default mode.

[student@workstation proj]$ ansible-playbook -l cs01 \
> multi-vendor-host-dnsinfo1.yml

PLAY [multi-vendor play to display host name, domain name, nameservers] ********

TASK [ios host, domain, nameserver] ********************************************
ok: [cs01]

TASK [display ios host settings] ***********************************************
ok: [cs01] => {
    "result.stdout": [
        "hostname cs01",
        "ip domain name lab.example.com",
        ""
    ]
}

TASK [vyos host, domain, nameserver] *******************************************
skipping: [cs01]

TASK [display vyos host settings] **********************************************
skipping: [cs01]

PLAY RECAP *********************************************************************
cs01                      : ok=2   changed=0   unreachable=0   failed=0

[student@workstation proj]$ ansible-playbook multi-vendor-host-dnsinfo1.yml