dcnm_fabric: Fix controller feature evaluation and add initial ND 4.0 support

[allenrobel]

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Ansible Version and collection version

ansible [core 2.17.5]
  config file = /Users/arobel/.ansible.cfg
  configured module search path = ['/Users/arobel/repos/ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/arobel/repos/ndfc-python/.venv/lib/python3.12/site-packages/ansible
  ansible collection location = /Users/arobel/repos/ansible/collections
  executable location = /Users/arobel/repos/ndfc-python/.venv/bin/ansible
  python version = 3.12.4 (main, Jun  6 2024, 18:26:44) [Clang 15.0.0 (clang-1500.3.9.4)] (/Users/arobel/repos/ndfc-python/.venv/bin/python)
  jinja version = 3.1.4
  libyaml = True

DCNM version

• V 3.6.0

Affected module(s)

• dcnm_fabric

Ansible Playbook

Note, the below playbook does work in my ND 4.0 setup. However, others are reporting that simple fabric creation does not work. The error is pasted below. From this error, it's clear response for endpoint /appcenter/cisco/ndfc/api/v1/fm/features is empty.

TASK [cisco.nac_dc_vxlan.create : Manage fabric ND-VXLAN-test in NDFC] ********************************************************************************************************************************************************************************
fatal: [nac-ndfc1]: FAILED! => {"changed": false, "msg": "Merged.get_need: Features required for fabric ND-VXLAN-test of type VXLAN_EVPN are not running on the controller. Review controller settings at Fabric Controller -> Admin -> System Settings -> Feature Management", "response": [{}], "result": [{}]}

- name: test dcnm_fabric_dcnm
  hosts: ndfc
  tasks:
    -   name: merged fabrics (dcnm_send)
        cisco.dcnm.dcnm_fabric:
            state: merged
            config:
             -   FABRIC_NAME: VXLAN_Fabric
                 FABRIC_TYPE: VXLAN_EVPN
                 BGP_AS: 65000
             -   FABRIC_NAME: MSD_Fabric
                 FABRIC_TYPE: VXLAN_EVPN_MSD
             -   FABRIC_NAME: LAN_Fabric
                 FABRIC_TYPE: LAN_CLASSIC
             -   FABRIC_NAME: ISN
                 BGP_AS: 65022
                 FABRIC_TYPE: ISN
        register: result
    -   debug:
            var: result

Debug Output

Expected Behavior

ND 4.0 output for the API endpoint /appcenter/cisco/ndfc/api/v1/fm/features no longer includes the following objects:

• lan
• pnm
• vxlan

These objects are used by the dcnm_fabric module when interacting with an ND 3.2.1e or earlier controller to determine if a given fabric type (VXLAN_EVPN, IPFM, LAN_CLASSIC, ISN, etc) can be created. For example, VXLAN_EVPN fabric type requires that the "vxlan" feature's oper_state == enabled.

With ND 4.0's unified architecture, the above objects presumably are no longer required (likely they are enabled without the user having to explicitly enable them).

Actual Behavior

See Expected Behavior

Steps to Reproduce

Attempt to create a fabric with ND 4.0 using the dcnm_fabric module.

In my lab, creating VXLAN_EVPN, MSD, and LAN_CLASSIC fabrics worked, but others have reported this not to be the case. Hence, need to investigate further.

Action items

• Determine if ND 4.0 enables the above features without user intervention.
• If these features are "always on", then we can bypass the feature check for ND 4.0.
• If not, and a new endpoint is available that provides the status of these features, use the new endpoint for ND 4.0.

Potential fixes

• Disable the feature check for ND 4.0 by wrapping lines 3035-3042 in dcnm_fabric.py in a conditional that tests for ND 3.x.
• If a new endpoint is available in ND 4.0 that provides the status of these features, use it (again, based on a conditional to discriminate between ND 3.0 and ND 4.0)>.

References

Below are gists containing the ND 3.2.1e vs ND 4.0 output for the following endpoint:

/appcenter/cisco/ndfc/api/v1/fm/features

ND 3.2.1e output

ND 4.0 output