Feat(performance): Use protobuf as default type instead of json

[RiskyAdventure]

Issue

Currently the controller only accepts the JSON responses from kube-apiserver. Accepting the more efficient Protobuf representation responses will improve performance at scale. This affects majorly the Pod cache ListWatch that is set here and can act as a bottleneck in clusters with large amount of pods.

By default, Kubernetes returns objects serialized to JSON with content type application/json. This is the default serialization format for the API. However, clients may request the more efficient Protobuf representation of these objects for better performance at scale.

Discussion on issue 3749 requested protobuf as the default vs. using flags to enable.
#3749

Description

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the docs directory)
• Manually tested
• [ x] Made sure the title of the PR is a good description that can go into the release notes

BONUS POINTS checklist: complete for good vibes and maybe prizes?! 🤯

• Backfilled missing tests for code in same general area 🎉
• Refactored something and made the world a better place 🌟

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: RiskyAdventure / name: Shane Corbett (a506190)

[k8s-ci-robot]

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[k8s-ci-robot]

Hi @RiskyAdventure. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[zac-nixon]

I think it's a good change but curious why the feature flag approach wasn't taken? The linked issue doesn't have much details.

[RiskyAdventure]

I think it's a good change but curious why the feature flag approach wasn't taken? The linked issue doesn't have much details.

I should've covered that, thank you for asking.

• Other projects such as aws-ebs-csi-driver do this by default. It would be a confusing customer experience to have to change a flag on this project, but not other common AWS drivers.
  kubernetes-sigs/aws-ebs-csi-driver@75421fa

• The serialization impact is difficult to troubleshoot as you need to pull the annotations on the audit log to understand if you're having this problem. Since the performance impact can be quite substantial, having a default set, would potentially prevent customer issues from happening in the first place.

[zac-nixon]

Sounds great. It seems that protobuf is enabled by default in the Kube API server as well.
https://kubernetes.io/docs/reference/using-api/api-concepts/#alternate-representations-of-resources

/ok-to-test
/lgtm

[oliviassss]

/lgtm

[zac-nixon]

/test pull-aws-load-balancer-controller-e2e-test

[k8s-ci-robot]

@RiskyAdventure: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-aws-load-balancer-controller-e2e-test	a506190	link	true	/test pull-aws-load-balancer-controller-e2e-test

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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