Ansible – Basic Playbook

The goal of this post is to provide you with a simple way to utilize Ansible 2.x and obtain data from Cisco IOS devices by running “show” commands. Github Reference.

Ansible Installation:

Before starting, make sure you have ansible installed.

Create a working directory:

mkdir ansible_play
cd ansible_play

Create the following 4 files within the “ansible_play” directory:

ansible.cfg
hosts
secrets.yml
show_code.yml

Among the 4 files provided in this example, the “hosts” and “secrets.yml” file would have to be altered to suit your requirements. The other 2 files, “ansible.cfg” and “show_code.yml” can be used as-is.

The contents of the above files will be like this:

$ cat ansible.cfg

[defaults]
hostfile = ./hosts
host_key_checking=False
timeout = 5

For now, use the contents as provided above for the “ansible.cfg” file.

$ cat hosts

[ios]
switch1

The hosts file will have the switches/routers that you would like to use for running the ansible-playbook. In my case, I am using “switch1”. The 1st line “[ios]” is the name of the hosts that will be referenced in the ansible-playbook.

$ cat secrets.yml

---
creds:
  username: cisco
  password: ciscopassword
  auth_pass: ciscoauth

This file contains the login information required to access the devices in the hosts file.

$ cat show_code.yml

---
- hosts: ios
  gather_facts: no
  connection: local
 
  tasks:
  - name: OBTAIN LOGIN CREDENTIALS
    include_vars: secrets.yml
 
  - name: DEFINE PROVIDER
    set_fact:
      provider:
        host: "{{ inventory_hostname }}"
        username: "{{ creds['username'] }}"
        password: "{{ creds['password'] }}"
        auth_pass: "{{ creds['auth_pass'] }}"
 
  - name: SHOW VERSION
    ios_command:
      provider: "{{ provider }}"
      commands:
        - show version | i Version
    register: write
 
  - debug: var=write.stdout_lines

Executing the ansible playbook:

$ ansible-playbook show_code.yml

PLAY [ios] *********************************************************************

TASK [OBTAIN LOGIN CREDENTIALS] ************************************************
ok: [switch1]

TASK [DEFINE PROVIDER] *********************************************************
ok: [switch1]

TASK [SHOW VERSION] ************************************************************
ok: [switch1]

TASK [debug] *******************************************************************
ok: [switch1] => {
    "write.stdout_lines": [
        [
            "Cisco IOS Software, Catalyst 4500 L3 Switch  Software (cat4500e-ENTSERVICESK9-M), Version 15.2(2)E3, RELEASE SOFTWARE (fc3)"
        ]
    ]
}

PLAY RECAP *********************************************************************
switch1               : ok=4    changed=0    unreachable=0    failed=0