Ansible 네트워크 자동화 – 5

앤시블 네트워크 자동화 -5

ansible 네트워크 telnet 사용하기

오래된 네트워크 장비는 ssh를 지원하지 않을 수도 있다. 이런 경우에, telnet을 사용해야 하며, ansible.netcommon 컬렉션의 일부분인 플러그인을 사용하면 된다.

ansible-galaxy 명령으로 해당 컬렉션을 설치한다. 이미 설치되어 있으면 아래와 같은 메시지가 보인다.

$ ansible-galaxy collection install ansible.netcommon
Process install dependency map
Starting collection install process
Skipping 'ansible.netcommon' as it is already installed

참고문서(https://docs.ansible.com/ansible/latest/collections/ansible/netcommon/telnet_module.html)의 예제를 기본으로 플레이북을 작성하였으나, 작동하지 않는다.

---
- name: Telnet test....
  ansible.netcommon.telnet:
    user: cisco
    password: cisco
    login_prompt: 'Username: '
    prompts:
    - '[>#]'
    command:
    - terminal length 0
    - show version

플레이북을 실행하면 다음 에러가 발생한다.

$ ansible-playbook get_version.yml -i hosts.yml
ERROR! 'ansible.netcommon.telnet' is not a valid attribute for a Play

두번째 문서(블로그)를 참고하여 플레이북을 아래와 처럼 수정했다.

$ cat get_arp.yml
---
- name: Telnet test
  connection: local
  gather_facts: false
  hosts: all

  tasks:
    - name: telnet test...
      ansible.netcommon.telnet:
        user: admin
        password: adminpasswd
        login_prompt: 'Username: '
        password_prompt: 'Password: '
        prompts:
          - '[>|#]'
        command:
          - terminal length 0
          - show version
      register: version

    - name: output
      debug:
        msg: "{{ version }}"

인벤토리는 다음처럼 작성했다.

$ cat hosts.yml
---
switches:
  hosts:
    LAN1:
      ansible_host: 192.168.250.1
    LAN2:
      ansible_host: 192.168.210.1
  vars:
    ansible_network_os: cisco.ios.ios
    #ansible_user: admin

wifi:
  hosts:
    WIFI:
      ansible_host: 192.168.245.25
  vars:
    ansible_network_os: extreme.exos.exos

이제, 플레이북을 실행하면 잘 된다.

$ ansible-playbook get_arp.yml -i hosts.yml -l LAN1

PLAY [Get ARP information from ios] ****************************************************************************

TASK [telnet test...] ******************************************************************************************
changed: [LAN1]

TASK [output] **************************************************************************************************
ok: [LAN1] => {
    "msg": {
        "changed": true,
        "failed": false,
        "output": [
            "terminal length 0\r\nlib_4507#",
            "show version\r\nCisco IOS Software, Catalyst 4500 L3 Switch Software (cat4500-ENTSERVICES-M), Version 12.2(54)SG, RELEASE SOFTWARE (fc3)\r\nTechnical Support: http://www.cisco.com/techsupport\r\nCopyright (c) 1986-2010 by Cisco Systems, Inc.\r\nCompiled Sun 27-Jun-10 04:53 by prod_rel_team\r\nImage text-base: 0x10000000, data-base: 0x121F5B44\r\n\r\nROM: 12.2(20r)EW1\r\nDagobah Revision 226, Swamp Revision 31\r\n\r\nlib_4507 uptime is 6 weeks, 20 hours, 45 minutes\r\nUptime for this control processor is 6 weeks, 20 hours, 44 minutes\r\nSystem returned to ROM by power-on\r\nSystem restarted at 17:16:50 KST Sun Feb 21 2021\r\nSystem image file is \"bootflash:cat4500-entservices-mz.122-54.SG.bin\"\r\n\r\ncisco WS-C4507R (MPC8245) processor (revision 14) with 524288K bytes of memory.\r\nProcessor board ID FOX101502JB\r\nMPC8245 CPU at 333Mhz, Supervisor IV\r\nLast reset from PowerUp\r\n3 Virtual Ethernet interfaces\r\n62 Gigabit Ethernet interfaces\r\n403K bytes of non-volatile configuration memory.\r\n\r\nConfiguration register is 0x2102\r\n\r\nlib_4507#"
        ]
    }
}

PLAY RECAP *****************************************************************************************************
LAN1                    : ok=2    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

이제, telnet만 지원되는 구형장비에도 앤시블 사용이 가능하게 되었다.

참고문서:
https://docs.ansible.com/ansible/latest/collections/ansible/netcommon/telnet_module.html
https://blog.gainskills.top/2018/09/04/ansible-access-network-via-telnet/