feat(entities): add updated_at column for entities

[liverpool8056]

Summary

add updated_at column for entities

Checklist

• The Pull Request has tests
• There's an entry in the CHANGELOG
• There is a user-facing docs PR against https://github.com/Kong/docs.konghq.com - PUT DOCS PR HERE

Full changelog

• [Implement ...]

Issue reference

• FTI-1294
• FTI-1292
• FTI-2103
• https://github.com/Kong/kong-ee/pull/4775

[hbagdi]

What about workspaces.lua, clustering_data_planes.lua?
Should we not add the missing timestamps in them as well?

[liverpool8056]

@hbagdi workspaces is not supported in ce, I will do make it in ee.
For clustering_data_planes, I think it is not an user-oriented entity, and I have no idea in which scenario we would use it, so not added this time.

[chronolaw]

If we need not to deal with version compatibility problem, I think this PR is OK.

[vm-001]

@hbagdi workspaces is not supported in ce, I will do make it in ee. For clustering_data_planes, I think it is not an user-oriented entity, and I have no idea in which scenario we would use it, so not added this time.

The workspace schema is under the kong/db/schema/entities folder. I think we can add updated_at to workspace as well.

[vm-001]

It looks good overall.

I'm not sure if adding a new field for these core entities would break DP-CP version compatibility.

[hbagdi]

@hbagdi workspaces is not supported in ce, I will do make it in ee.

The entity definition for it is right here: https://github.com/Kong/kong/blob/master/kong/db/schema/entities/workspaces.lua
Please introduce the timestamps in this PR. Adding it only in EE introduces unnecessary conflicts.

For clustering_data_planes, I think it is not an user-oriented entity, and I have no idea in which scenario we would use it, so not added this time.

The entity is user-facing and we expose a read-only endpoint for it: https://github.com/Kong/kong/blob/master/kong/api/routes/clustering.lua#L22.
The data for this entity is generated by the CP when DPs connect.
Please introduce the timestamps as it helps users determine when a DP was first connected to the CP.

[liverpool8056]

@hbagdi The last_seen field in clustering_data_plane seems have the same semantic with updated_at? If so, do we still have to add it?

[hbagdi]

@hbagdi The last_seen field in clustering_data_plane seems have the same semantic with updated_at? If so, do we still have to add it?

I recommend doing so for consistency than anything else. I see the point that it doesn't provide additional value.
I leave the decision up to you, I'm fine either way.

[bungle]

This one fix is still needed.

[bungle]

@liverpool8056 are the migration tests broken (because of something outside this PR)?

[vm-001]

After taking another look, there is something that should be adjusted. Have synced with @liverpool8056 offline.

1/ missing has_updated = true after modifying DP config.

kong/kong/clustering/compat/init.lua

Line 375 in 66895f6

config_entity.updated_at = nil

(Should add nil check before setting x.updated = nil

2/ Should add a test case against the new-added compatibility logic in spec/01-unit/19-hybrid/03-compat_spec.lua