VPA: Add automated flag generator for all components

[omerap12]

What type of PR is this?

/kind feature

What this PR does / why we need it:

Adds an automated script to generate VPA flags.Integrated into the current Makefile such as:

make document-flags

Which issue(s) this PR fixes:

Fixes #7589

Special notes for your reviewer:

Since this is a Go environment, I preferred using Go instead of Bash, Python, or other scripting languages.

Does this PR introduce a user-facing change?

NONE

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

NONE

[k8s-ci-robot]

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[adrianmoisey]

This is super cool, thank you!

I have some thoughts:

1. Would it be useful to make a script that combines all the flags into a single doc file, something like ./docs/flags.md. That way it will be easy to integrate into docs
2. Some of the output needs work, such as --eviction-rate-limit for the updater, its default is rendered as &{2367 - 0x140001eb6a0}
3. Some newlines are making their way into the tables, breaking the rendered markdown

[adrianmoisey]

Suggested change

	.PHONY: admission-flags
	admission-flags:
	.PHONY: document-flags
	document-flags:

Would it make sense to make the name of the Makefile job the same across all components?

[omerap12]

yeah it does! lol I feel dumb

[omerap12]

This is super cool, thank you!

I have some thoughts:

1. Would it be useful to make a script that combines all the flags into a single doc file, something like ./docs/flags.md. That way it will be easy to integrate into docs
2. Some of the output needs work, such as --eviction-rate-limit for the updater, its default is rendered as &{2367 - 0x140001eb6a0}
3. Some newlines are making their way into the tables, breaking the rendered markdown

1. Sure, I can handle that. It’ll just be a simple wrapper, probably like five lines in bash.
2. Thanks for pointing that out. I’ll check why it’s happening.
3. Ah, I see—it’s due to the multiline content. I’ll make adjustments.

[adrianmoisey]

1. Sure, I can handle that. It’ll just be a simple wrapper, probably like five lines in bash.

Yeah, I was thinking of a bash script that would do something like:

1. Run the make command for each file
2. Concatenate the outputs for all 3 into a single file (may be with a header that is a table of contents)
3. Move that file in ./docs/flags.md

[omerap12]

1. Sure, I can handle that. It’ll just be a simple wrapper, probably like five lines in bash.

Yeah, I was thinking of a bash script that would do something like:

1. Run the make command for each file
2. Concatenate the outputs for all 3 into a single file (may be with a header that is a table of contents)
3. Move that file in ./docs/flags.md

exactly what I'm doing now :)

[omerap12]

@adrianmoisey, you can now run the script with:
./create-flags-doc-vpa.sh (it works when run from within the hack directory).
Should I update the script to support running it from outside the hack directory as well?

[adrianmoisey]

Should I update the script to support running it from outside the hack directory as well?

Yup, I think so.
For #7608 I originally made my own script to do that, but ended up copying the logic in https://github.com/kubernetes/autoscaler/blob/1ba600754bd60d720b4634ece0e5b2e8efcefe78/vertical-pod-autoscaler/hack/generate-crd-yaml.sh

[adrianmoisey]

/lgtm

This is awesome, thanks!

[raywainman]

Thanks a lot for this!

/lgtm

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: omerap12, raywainman

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