Minimum k8s requirement in the error log and doc

[Leo6Leo]

Describe the bug
Currently, when you are running ./hack/install.sh, and you have a Kubernetes version does not satisfy with the minimum k8s version as required by Knative as suggested here.

The error logs just shows "E2E Test Failed, Error generating manifests". But when you try to describe eventing-controller, you will find out that it is failing because k8s version check failed.

{"level":"fatal","ts":"2024-03-25T15:28:36.576Z","logger":"controller","caller":"sharedmain/main.go:386","msg":"Version check failed","commit":"2aa8985","knative.dev/pod":"eventing-controller-847447489f-2sgf5","error":"kubernetes version \"1.22.5\" is not compatible, need at least \"1.28.0-0\" (this can be overridden with the env var \"KUBERNETES_MIN_VERSION\")","stacktrace":"knative.dev/pkg/injection/sharedmain.CheckK8sClientMinimumVersionOrDie\n\tknative.dev/pkg@v0.0.0-20240318073042-db6f3b074e8c/injection/sharedmain/main.go:386\nknative.dev/pkg/injection/sharedmain.MainWithConfig\n\tknative.dev/pkg@v0.0.0-20240318073042-db6f3b074e8c/injection/sharedmain/main.go:256\nknative.dev/pkg/injection/sharedmain.MainWithContext\n\tknative.dev/pkg@v0.0.0-20240318073042-db6f3b074e8c/injection/sharedmain/main.go:210\nmain.main\n\tknative.dev/eventing/cmd/controller/main.go:86\nruntime.main\n\truntime/proc.go:267"}

Expected behavior
If we can directly tell users that the minimum k8s version requirement is not met at the beginning, this can save them some time debugging the issue.

Also we should specify that there is a requirement for minimum k8s version in DEVELOPMENT.md.

To Reproduce

• Start the cluster with k8s version older than v1.28
• Run hack/install.sh

Knative release version

Additional context
Add any other context about the problem here such as proposed priority

/good-first-issue
/help-wanted

[knative-prow]

@Leo6Leo:
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Please ensure the request meets the requirements listed here.

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In response to this:

Describe the bug
Currently, when you are running ./hack/install.sh, and you have a Kubernetes version does not satisfy with the minimum k8s version as required by Knative as suggested here.

The error logs just shows "E2E Test Failed, Error generating manifests". But when you try to describe eventing-controller, you will find out that it is failing because k8s version check failed.

{"level":"fatal","ts":"2024-03-25T15:28:36.576Z","logger":"controller","caller":"sharedmain/main.go:386","msg":"Version check failed","commit":"2aa8985","knative.dev/pod":"eventing-controller-847447489f-2sgf5","error":"kubernetes version \"1.22.5\" is not compatible, need at least \"1.28.0-0\" (this can be overridden with the env var \"KUBERNETES_MIN_VERSION\")","stacktrace":"knative.dev/pkg/injection/sharedmain.CheckK8sClientMinimumVersionOrDie\n\tknative.dev/pkg@v0.0.0-20240318073042-db6f3b074e8c/injection/sharedmain/main.go:386\nknative.dev/pkg/injection/sharedmain.MainWithConfig\n\tknative.dev/pkg@v0.0.0-20240318073042-db6f3b074e8c/injection/sharedmain/main.go:256\nknative.dev/pkg/injection/sharedmain.MainWithContext\n\tknative.dev/pkg@v0.0.0-20240318073042-db6f3b074e8c/injection/sharedmain/main.go:210\nmain.main\n\tknative.dev/eventing/cmd/controller/main.go:86\nruntime.main\n\truntime/proc.go:267"}

Expected behavior
If we can directly tell users that the minimum k8s version requirement is not met at the beginning, this can save them some time debugging the issue.

Also we should specify that there is a requirement for minimum k8s version in DEVELOPMENT.md.

To Reproduce

• Start the cluster with k8s version older than v1.28
• Run hack/install.sh

Knative release version

Additional context
Add any other context about the problem here such as proposed priority

/good-first-issue
/help-wanted

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[pierDipi]

@Leo6Leo my concern is that we end up bloating the scripts with too many checks that we need to maintain as they are constantly changing, so I am not sure about this as it's very costly to maintan unless you know of a way that simple and doesn't require constant maintenance

[pierDipi]

Also we should specify that there is a requirement for minimum k8s version in DEVELOPMENT.md.

we can link to https://github.com/knative/community/blob/main/mechanics/RELEASE-SCHEDULE.md

[Leo6Leo]

I'm thinking about making a special script that we run first. This script will check important things like if we have the right version of Kubernetes and if the KO_DOCKER_REPO variable is set. To make things easier to keep up to date, I hope to get the minimum Kubernetes version needed directly from a specific place online, from the Knative project's code here. This way, we always know we're using the right version without having to manually check and update it.

If it is too complicated, I think it should be enough to indicate the requirement for min k8s version in DEVELOPMENT.md by linking to https://github.com/knative/community/blob/main/mechanics/RELEASE-SCHEDULE.md only.

@pierDipi

[Cali0707]

@Leo6Leo maybe instead of bloating the shell scripts, we can add a check into the test entry point on the go side, then we can call https://github.com/knative/pkg/blob/main/version/version.go#L52 (which is what is used to check the version anyways).