add metadata to agones webhook autoscaler request

[swermin]

What type of PR is this?

Uncomment only one /kind <> line, press enter to put that in a new line, and remove leading whitespace from that line:

/kind breaking
/kind bug
/kind cleanup
/kind documentation

/kind feature

/kind hotfix
/kind release

What this PR does / Why we need it:
This PR extends the webhook autoscaler with metadata, so that the the service retrieving the request can use the lables/annotations to do the calculation

Which issue(s) this PR fixes:
Closes #3951

Special notes for your reviewer:

[google-cla]

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[agones-bot]

Build Failed 😭

Build Id: 5ade9d2e-d20e-4cad-b76b-697960ab7ff0

Status: FAILURE

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[igooch]

Thanks for the contribution. Could you please also add unit and e2e tests?

[gongmax]

@swermin kindly ping on this, could you resolve the conflicts and address the above comments?

[swermin]

Yes ofc! I have unit tests ready and just left with the e2e tests. I’ll push the current changes and focus on the e2e tests today and this weekend if needed!

[agones-bot]

Build Failed 😭

Build Id: 166b3f1b-5297-4b2a-bc9b-3b0ec925abe5

Status: FAILURE

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[agones-bot]

Build Failed 😭

Build Id: 984531ec-7bcc-4fa4-bf36-089d5719a947

Status: FAILURE

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[swermin]

@igooch do you have any good suggestions on how to do the e2e tests for this?
Current default webhook autoscaler is using the example image to test the scaling. I feel like adding support in that image feels a bit weird but I have no good idea on how to add something

[agones-bot]

Build Failed 😭

Build Id: 0ef393db-4a59-403f-8729-4a86e54fb6d3

Status: FAILURE

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[igooch]

I just got back from being out of office, so I'm still catching up.

For the e2e tests, do you need to make changes to examples/autoscaler-webhook/main.go? Depending on the test you may be able to simply add MetaData to the default similar to https://github.com/googleforgames/agones/blob/c26f7371980418b56b816b13d265c9cc9d092f32/test/e2e/fleetautoscaler_test.go#L549C14-L549C38. If you do need to make changes to the examples/autoscaler-webhook/main.go, then a maintainer will need to build and push a new example autoscaler webhook image with the changes. That being said, it looks like the unit test is failing.

From the most recent build:

        	Test:       	TestApplyWebhookPolicyWithMetadata
        	            	actual  : 5
        	            	expected: 11
        	Error:      	Not equal: 
        	Error Trace:	/go/src/agones.dev/agones/pkg/fleetautoscalers/fleetautoscalers_test.go:618
    fleetautoscalers_test.go:618: 
--- FAIL: TestApplyWebhookPolicyWithMetadata (0.01s)

You'll need to run ~/agones/build$ make gen-crd-code to generate the deepcopy for pkg/apis/autoscaling/v1/fleetautoscaler.go, but even with that the test is still failing, so there's another issue going on.

[agones-bot]

Build Succeeded 🥳

Build Id: 00518f36-9edb-49bc-8c2a-b755dd8f48d1

The following development artifacts have been built, and will exist for the next 30 days:

• image: us-docker.pkg.dev/agones-images/ci/agones-controller:1.45.0-dev-9e74cc5
• image: us-docker.pkg.dev/agones-images/ci/agones-extensions:1.45.0-dev-9e74cc5
• image: us-docker.pkg.dev/agones-images/ci/agones-sdk:1.45.0-dev-9e74cc5-linux
• image: us-docker.pkg.dev/agones-images/ci/agones-ping:1.45.0-dev-9e74cc5
• image: us-docker.pkg.dev/agones-images/ci/agones-allocator:1.45.0-dev-9e74cc5
• Linux C++ SDK (build): agonessdk-1.45.0-dev-9e74cc5-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.45.0-dev-9e74cc5.zip

A preview of the website (the last 30 builds are retained):

• https://9e74cc5-dot-preview-dot-agones-images.appspot.com/

To install this version:

git fetch https://github.com/googleforgames/agones.git pull/3957/head:pr_3957 && git checkout pr_3957
helm install agones ./install/helm/agones --namespace agones-system --set agones.image.registry=us-docker.pkg.dev/agones-images/ci --set agones.image.tag=1.45.0-dev-9e74cc5