vrf_command

This Ansible Network role allows you to send VRF-aware network commands to network devices in a dynamic way. It currently works with IOS, EOS, and NXOS devices.

This role improves the default behavior of the following modules:

• ios_command
• nxos_command
• eos_command

Demonstration

Check Example Playbook 2 for details on how to use this role in a demonstration.

Requirements

None.

Role Variable

Update the following value based on your needs (see defaults/main.yml):

vrf_command_list:
  - "show ip route vrf <vrf>"
  - "show version"

The vrf_command_list should include all commands you want to run on your network devices. Use <vrf> in the commands to make them VRF-aware.

The <vrf> will be replaced with the available VRFs on the device, including the global table. For example, if a device has the VRFs dev and prod, the command show ip route vrf <vrf> will expand to:

• show ip route
• show ip route vrf dev
• show ip route vrf prod

You can also run regular commands that are not VRF-related.

Output Variable

The role creates a custom output variable called vrf_command_output for user convenience.

The data structure looks like this:

vrf_command_output:
  - command: "show ip route vrf dev"
      failed: False
      output: "...77.77.77.0 is directly connected, FastEthernet1/0\n..." (omitted)
  - command: "show blah blah"
      failed: True
      output: "...% Invalid input detected at..." (omitted)

The data structure returns a list. Each item in the list has three keys:

• command - The command that was run on the network device.
• failed - A boolean that shows if the command failed (true) or succeeded (false).
• output - The output from the command.

Example Playbook 1

This example playbook shows how to use the role in a simple way.

- hosts: all

  vars:
    vrf_command_list:
      - "show ip interface brief vrf <vrf>"
      - "show ip route vrf <vrf>"
      - "show interface status"
      - "show version"
      
  roles:
      - syedur_rahman.vrf_command

Example Playbook 2

This example playbook shows how to use vrf_command_output to save results to text files.

- hosts: all

  vars:
    vrf_command_list:
      - "show ip route vrf <vrf>"
      
  roles:
    - syedur_rahman.vrf_command

- hosts: localhost

  tasks:
  - template:
      src: "show_command.j2"
      dest: "{{ item }}.txt"
    loop: "{{ groups['all'] }}"

Here's the show_command.j2 template:

{% for show_command_info in hostvars[item]['vrf_command_output'] %}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
{{ show_command_info['command'] }}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
{{ show_command_info['output'] }}
{% endfor %}

This produces a text file per device containing the following format.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
show ip route vrf management
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
IP Route Table for VRF "management"
'*' denotes best ucast next-hop
'**' denotes best mcast next-hop
'[x/y]' denotes [preference/metric]
'%<string>' in via output denotes VRF <string>

192.168.12.0/24, ubest/mbest: 1/0, attached
    *via 192.168.12.135, mgmt0, [0/0], 05:12:12, direct
192.168.12.135/32, ubest/mbest: 1/0, attached
    *via 192.168.12.135, mgmt0, [0/0], 05:12:12, local

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
show ip route
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
IP Route Table for VRF "default"
'*' denotes best ucast next-hop
'**' denotes best mcast next-hop
'[x/y]' denotes [preference/metric]
'%<string>' in via output denotes VRF <string>

2.2.2.0/24, ubest/mbest: 1/0, attached
    *via 2.2.2.2, Lo100, [0/0], 05:12:28, direct
2.2.2.2/32, ubest/mbest: 1/0, attached
    *via 2.2.2.2, Lo100, [0/0], 05:12:28, local
2.3.4.0/24, ubest/mbest: 1/0, attached
    *via 2.3.4.5, Lo23, [0/0], 05:12:28, direct
2.3.4.5/32, ubest/mbest: 1/0, attached
    *via 2.3.4.5, Lo23, [0/0], 05:12:28, local

License

MIT

Author Information

This role was created by Syedur Rahman in 2020.