T6773: Implement configuration and logic for DDNS updates in Kea DHCP4

[abukharov]

Change Summary

This PR introduces support for RFC-2136 DDNS updates in Kea DHCP4 server.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

https://vyos.dev/T6773

Related PR(s)

vyos/vyos-documentation#1561

Component(s) name

dhcp-server

Proposed changes

How to test

Set up a Technitium DNS in a container inside VyOS. Set up DDNS updates as follows:

set service dhcp-server dynamic-dns-update send-updates
set service dhcp-server dynamic-dns-update use-conflict-resolution
set service dhcp-server dynamic-dns-update tsig-key-name mydomain-net algorithm hmac-sha256
set service dhcp-server dynamic-dns-update tsig-key-name mydomain-net secret eWF5YW15bGl0dGxla2V5IQ==
set service dhcp-server dynamic-dns-update forward-ddns-domain-name mydomain.net key-name mydomain-net
set service dhcp-server dynamic-dns-update forward-ddns-domain-name mydomain.net dns-server 1 address '172.18.0.254'
set service dhcp-server dynamic-dns-update forward-ddns-domain-name mydomain.net dns-server 1 port 1053

Get the DHCP server to issue some leases and check if the DNS server gets updated.

Smoketest result

sh-5.2# ./test_service_dhcp-server.py
test_dhcp_dynamic_dns_update (__main__.TestServiceDHCPServer.test_dhcp_dynamic_dns_update) ... ok
test_dhcp_exclude_in_range (__main__.TestServiceDHCPServer.test_dhcp_exclude_in_range) ... ok
test_dhcp_exclude_not_in_range (__main__.TestServiceDHCPServer.test_dhcp_exclude_not_in_range) ... ok
test_dhcp_high_availability (__main__.TestServiceDHCPServer.test_dhcp_high_availability) ... ok
test_dhcp_high_availability_standby (__main__.TestServiceDHCPServer.test_dhcp_high_availability_standby) ... ok
test_dhcp_multiple_pools (__main__.TestServiceDHCPServer.test_dhcp_multiple_pools) ... ok
test_dhcp_on_interface_with_vrf (__main__.TestServiceDHCPServer.test_dhcp_on_interface_with_vrf) ... ok
test_dhcp_relay_server (__main__.TestServiceDHCPServer.test_dhcp_relay_server) ... ok
test_dhcp_single_pool_options (__main__.TestServiceDHCPServer.test_dhcp_single_pool_options) ... ok
test_dhcp_single_pool_options_scoped (__main__.TestServiceDHCPServer.test_dhcp_single_pool_options_scoped) ... ok
test_dhcp_single_pool_range (__main__.TestServiceDHCPServer.test_dhcp_single_pool_range) ... ok
test_dhcp_single_pool_static_mapping (__main__.TestServiceDHCPServer.test_dhcp_single_pool_static_mapping) ... ok

----------------------------------------------------------------------
Ran 12 tests in 38.710s

OK
sh-5.2#

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[github-actions]

👍
No issues in PR Title / Commit Title

[github-actions]

✅ No issues found in unused-imports check.. Please refer the workflow run

[github-actions]

CI integration ❌ failed!

Details

CI logs

• CLI Smoketests (no interfaces) ❌ failed
• CLI Smoketests (interfaces only) 👍 passed
• Config tests ❌ failed
• RAID1 tests 👍 passed
• TPM tests 👍 passed