Add Dell Enterprise SONiC 'ipv6_router_advertisement' module

[ArunSaravananBalachandran]

SUMMARY

• Add Enterprise SONiC 'ipv6_router_advertisement' resource module:
  • Provide data definitions in 'argspec'.
  • Implement 'facts' to gather facts for the module.
  • Implement 'config' to apply configurations for merged, deleted, replaced and overridden states.
  • Implement support for 'check' and 'diff' modes.
• Define regression and unit test cases to verify correct functionality of ipv6_router_advertisement resource module.

Model PR: ansible-network/resource_module_models#290

GitHub Issues

List the GitHub issues impacted by this PR. If no Github issues are affected, please indicate this with "N/A".

GitHub Issue #
N/A

ISSUE TYPE

• Feature Pull Request

COMPONENT NAME

• sonic_ipv6_router_advertisement

OUTPUT

ADDITIONAL INFORMATION

Checklist:

• I have performed a self-review of my own code to ensure there are no formatting, linting, or security issues
• I have verified that new and existing unit tests pass locally with my changes
• I have not allowed coverage numbers to degenerate
• I have maintained at least 90% code coverage
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have maintained backward compatibility or have provided any relevant "breaking_changes" descriptions in a "fragment" file in the "changelogs/fragments" directory of this repository.
• I have provided a summary for this PR in valid "fragment" file format in the "changelogs/fragments" directory of this repository branch. Reference : Ansible Change Log Document

How Has This Been Tested?

Regression report: ipv6_router_advertisement_regression-2025-05-08-16-28-41.zip

ansible-lint logs:

ansible-lint plugins/modules/sonic_ipv6_router_advertisement.py tests/regression/roles/sonic_ipv6_router_advertisement/ tests/unit/modules/network/sonic/fixtures/sonic_ipv6_router_advertisement.yaml

Passed: 0 failure(s), 0 warning(s) on 10 files. Last profile that met the validation criteria was 'production'.

[kerry-meyer]

Overall, the code proposed in this PR looks very good. The code structure is great. The logic all looks correct and complete. I am posting a few minor comments, plus the following question on the regression test results:

---

For test case 4 (deleted), there is a deletion of the "1001::2000" prefix for Vlan101, but the command doesn't modify the other prefix ("1001::1000"). For that prefix, the "after", "after(Generated)" and diff show two (default?) options that aren't present in the "before".
Is this correct behavior? If so, why does it happen?
Here is the output snippet that made me wonder about this (because it showed added options for a deletion case):

 "--- 66,76 ----",
  "          'ra_fast_retrans': true,",
  "          'ra_prefixes': [",
  "              {",
  "+                 'no_autoconfig': false,",
  "                  'off_link': true,",
  "                  'prefix': '1001:1000::/64',",
  "+                 'router_address': false,",
  "                  'valid_lifetime': 2400",
  "              }",
  "          ],",
  "          'suppress': false"
]

[kerry-meyer]

Overall, the code proposed in this PR looks very good. The code structure is great. The logic all looks correct and complete. I am posting a few minor comments and have separately posted a question on the regression results.

[kerry-meyer]

Thanks for addressing the posted review comments and questions.

All current proposed code changes and corresponding test results look good.

Thank you for providing the enterprise_sonic Ansible support for IPv6 neighbor discovery.

Approved.