dhcp: T7052: Refactor kea dhcp op-mode functions to vyos.kea

[indrajitr]

Relocate the kea dhcp op-mode functions to kea helper functions in vyos.kea. This allows the functions to be reused by other scripts, not just op-mode wrappers.

This moves the source of truth for the op-mode commands to the actual running kea instance, rather than VyOS config path.

Also, apply some minor code cleanup, rename show_pool_statistics to show_server_pool_statistics, and make some of the mappings consistent across the functions.

Change summary

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/T7052
• https://vyos.dev/T6948

Related PR(s)

How to test / Smoketest result

Try op-mode commands:

show dhcp server static-mappings
show dhcp server leases
show dhcp server statistics

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

[dmbaturin]

I wonder if it's a good idea to move warning text to constants, if it appears in more than one place.

[indrajitr]

I wonder if it's a good idea to move warning text to constants, if it appears in more than one place.

Of course! I missed that part. Update coming up shortly.

[github-actions]

CI integration 👍 passed!

Details

CI logs

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