# 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.

Resource starting configuration | task-provided configuration (YAML) | Final resource configuration on device
--- | --- | ---

    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

merged

      interface loopback100
       ip address 10.10.1.100 255.255.255.0
       ipv6 address FC00:100/64
       ipv6 address FC00:101/64

replaced

      interface loopback100
       no ip address
       ipv6 address FC00:100/64
       ipv6 address FC00:101/64

overridden
  Incorrect use case. This would remove all interfaces from the device
(including the mgmt interface) except
  the configured loopback100

deleted

      interface loopback100
       no ip address

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

See also

Network Features in Ansible 2.9
  A introductory blog post on network resource modules.
Deep Dive into Network Resource Modules
  A deeper dive presentation into network resource modules.