api + implementation: AgentgatewayParameters

[chandler-solo]

Description

This is an implementation of a continuation of the API in #13007. It is intended to be followed up with:

• breaking changes to the API that simplify this code by removing backwards compatibility with kgateway GatewayParameters Controller kgateway.dev/agentgateway disallows GatewayParameters #13054
• refactoring of HelmConfig into two parts, one for envoy and one for agentgateway HelmConfig and Deployer split for agentgateway and envoy #13068
• PDBs and HPAs

You can see more precisely, and in context, how an end user would use this in test/deployer/testdata/agentgateway-params-primary.yaml or test/deployer/testdata/agentgateway-strategic-merge-patch-out.yaml

See https://github.com/howardjohn/kgateway/compare/api/agwp...chandler-solo:kgateway:chandler/api/agwp?expand=1 to understand what has changed vs. #13007

Relevant text from the description of #13007, highlighting the desire to make it possible to avoid AgentgatewayParameters' RawConfig, lightly edited because this API differs a little, follows:

The idea of the API is to primarily rely on 'overlays'. An overlay allows users to specify a metadata/spec for objects, which is an opaque map of fields that is strategic-merge-patch applied over the generated objects. This exposes every field of the underlying APIs, without requiring us to expose each API individually with a slightly different API; users can just use the Kubernetes APIs as they intended.

In order to facilitate very common configuration, or configuration that benefits from being broken out. Currently, this includes memory and CPU resources, image, etc. We should avoid creeping this too much. Likely the following are potentially in scope (copied from AGW underlying config):

|config||
|config.enableIpv6||
|config.localXdsPath|Local XDS path. If not specified, the current configuration file will be used.|
|config.caAddress||
|config.caAuthToken||
|config.xdsAddress||
|config.xdsAuthToken||
|config.namespace||
|config.gateway||
|config.trustDomain||
|config.serviceAccount||
|config.clusterId||
|config.network||
|config.adminAddr|Admin UI address in the format "ip:port"|
|config.statsAddr|Stats/metrics server address in the format "ip:port"|
|config.readinessAddr|Readiness probe server address in the format "ip:port"|
|config.connectionTerminationDeadline||
|config.connectionMinTerminationDeadline||
|config.workerThreads||
|config.metrics||
|config.metrics.remove||
|config.metrics.fields||
|config.metrics.fields.add||
|config.hbone||
|config.hbone.windowSize||
|config.hbone.connectionWindowSize||
|config.hbone.frameSize||
|config.hbone.poolMaxStreamsPerConn||
|config.hbone.poolUnusedReleaseTimeout|

Change Type

/kind feature

Changelog

Added a new AgentgatewayParameters API in `agentgateway.dev/v1alpha1`

Additional Notes

[chandler-solo]

The test/deployer diffs would be greatly simplified if we first landed a PR that only changed the *-out.yaml files' map key ordering to alphabetical instead of 'as helm renders it'.

[josh-pritchard]

Not a full review yet but have some feedback. Overall I really like the direction and I think we are simplifying some things by not having a package in internal & pkg. I am looking forward to you bringing the existing generator code in-line with this when this merges

[chandler-solo]

The test/deployer diffs would be greatly simplified if we first landed a PR that only changed the *-out.yaml files' map key ordering to alphabetical instead of 'as helm renders it'.

I've broken out a prequel PR #13037; this review will shrink once that lands and this is updated.

[chandler-solo]

I duplicated the 'Image' API now that GVKs have split.

[howardjohn]

Overall looks really good

[chandler-solo]

Not done with review comments. I'll leave PDBs and HPAs to a follow up since those are new features and I'd like to discuss them further.

[chandler-solo]

#13037 has landed and this has been updated. No *-out.yaml golden files were changed (except brand new ones).

[howardjohn]

LGTM with followups

Add PDB and HPA
Remove GatewayParams support
Split HelmConfig for AGW and KGW
Merge GC and Gateway level params

[chandler-solo]

@howardjohn, your commits on #13007 were squashed with mine into a single commit because it's the safest, fastest way I could think of to solve the problem of forgetting to sign off on a commit in the middle of the stack, which I did by using 'git revert' instead of 'git revert --signoff'.

[chandler-solo]

I went ahead and proposed an API addition rawConfig so that the ~200 config options there. It is now obvious when a change to your config will propagate to your actual serving data-plane pods.

[chandler-solo]

/retest

[howardjohn]

can be a followup: would prefer to do min: 15s vs minSeconds. This would be more consistent with other agentgateway resources

[chandler-solo]

Since I had to fix json vs. Json, I changed this too.

[howardjohn]

I believe agentgateway requires this to be json not Json

[chandler-solo]

I tested it locally and you are correct. Changed it.

[chandler-solo]

/merge

[chandler-solo]

/merge