Network resource modules

Ansible 2.9 introduced network resource modules to simplify and standardize how you manage different network devices.

• Understanding network resource modules
• Network resource module states
• Using network resource modules
• Example: Verifying the network device configuration has not changed

Understanding network resource modules

Network devices separate configuration into sections (such as interfaces, VLANS, etc) that apply to a network service. Ansible network resource modules take advantage of this to allow you to configure subsections or resources within the network device configuration. Network resource modules provide a consistent experience across different network devices.

Network resource module states

You use the network resource modules by assigning a state to what you want the module to do. The resource modules support the following states:

merged

Ansible merges the on-device configuration with the provided configuration in the task.

replaced

Ansible replaces the on-device configuration subsection with the provided configuration subsection in the task.

overridden

Ansible overrides the on-device configuration for the resource with the provided configuration in the task. Use caution with this state as you could remove your access to the device (for example, by overriding the management interface configuration).

deleted

Ansible deletes the on-device configuration subsection and restores any default settings.

gathered

Ansible displays the resource details gathered from the network device and accessed with the gathered key in the result.

rendered

Ansible renders the provided configuration in the task in the device-native format (for example, Cisco IOS CLI). Ansible returns this rendered configuration in the rendered key in the result. Note this state does not communicate with the network device and can be used offline.

parsed

Ansible parses the configuration from the running_configuration option into Ansible structured data in the parsed key in the result. Note this does not gather the configuration from the network device so this state can be used offline.

Using network resource modules

This example configures L3 interface resource on a Cisco IOS device, based on different state settings.

- name: configure l3 interface
  ios_l3_interfaces:
    config: "{{ config }}"
    state: <state>

The following table shows an example of how an initial resource configuration changes with this task for different states.

interface loopback100
 ip address 10.10.1.100 255.255.255.0
 ipv6 address FC00:100/64

config:
- ipv6:
 - address: fc00::100/64
 - address: fc00::101/64
 name: loopback100

Network resource modules return the following details:

• The before state - the existing resource configuration before the task was executed.
• The after state - the new resource configuration that exists on the network device after the task was executed.
• Commands - any commands configured on the device.

ok: [nxos101] =>
  result:
    after:
      contact: IT Support
      location: Room E, Building 6, Seattle, WA 98134
      users:
      - algorithm: md5
        group: network-admin
        localized_key: true
        password: '0x73fd9a2cc8c53ed3dd4ed8f4ff157e69'
        privacy_password: '0x73fd9a2cc8c53ed3dd4ed8f4ff157e69'
        username: admin
    before:
      contact: IT Support
      location: Room E, Building 5, Seattle HQ
      users:
      - algorithm: md5
        group: network-admin
        localized_key: true
        password: '0x73fd9a2cc8c53ed3dd4ed8f4ff157e69'
        privacy_password: '0x73fd9a2cc8c53ed3dd4ed8f4ff157e69'
        username: admin
    changed: true
    commands:
    - snmp-server location Room E, Building 6, Seattle, WA 98134
    failed: false

Example: Verifying the network device configuration has not changed

The following playbook uses the eos_l3_interfaces module to gather a subset of the network device configuration (Layer 3 interfaces only) and verifies the information is accurate and has not changed. This playbook passes the results of eos_facts directly to the eos_l3_interfaces module.

- name: Example of facts being pushed right back to device.
  hosts: arista
  gather_facts: false
  tasks:
    - name: grab arista eos facts
      eos_facts:
        gather_subset: min
        gather_network_resources: l3_interfaces

- name: Ensure that the IP address information is accurate.
  eos_l3_interfaces:
    config: "{{ ansible_network_resources['l3_interfaces'] }}"
    register: result

- name: Ensure config did not change.
  assert:
    that: not result.changed