[extension/cgroupruntime] Be aware of ECS task and CPU limits

[r0mdau]

Description

Allow the cgroupruntime extension to set GOMAXPROCS based on AWS ECS metadata. See related issue for detailed informations.

Link to tracking issue

Fixes #36814

Testing

Added integration test with httptest for the ECS metadata endpoint.

Something to clarify: #36617 (comment)

Documentation

Added extension name and link in the README.

[rogercoll]

Thanks for adding this, the code lgtm, just left a couple of nits/question.

[rogercoll]

nit

Suggested change

	var undo func()
	var err error
	if gomaxecs.IsECS() {
	undo, err = gomaxecs.Set(gomaxecs.WithLogger(func(str string, params ...any) {
	set.Logger.Debug(fmt.Sprintf(str, params))
	}))
	} else {
	undo, err = maxprocs.Set(maxprocs.Logger(func(str string, params ...any) {
	set.Logger.Debug(fmt.Sprintf(str, params))
	}))
	}
	return undoFunc(undo), err
	if gomaxecs.IsECS() {
	return gomaxecs.Set(gomaxecs.WithLogger(func(str string, params ...any) {
	set.Logger.Debug(fmt.Sprintf(str, params))
	}))
	} else {
	return maxprocs.Set(maxprocs.Logger(func(str string, params ...any) {
	set.Logger.Debug(fmt.Sprintf(str, params))
	}))
	}

[r0mdau]

Looks good, today is nit day, wdyt ?

			if gomaxecs.IsECS() {
				return gomaxecs.Set(gomaxecs.WithLogger(func(str string, params ...any) {
					set.Logger.Debug(fmt.Sprintf(str, params))
				}))
			}
			return maxprocs.Set(maxprocs.Logger(func(str string, params ...any) {
				set.Logger.Debug(fmt.Sprintf(str, params))
			}))

[rogercoll]

Looks great to me 🚀

[rogercoll]

Initially, I thought that the component's Go version needed to updated all at once, but it seems there are some components already on go 1.22.7. 👍

[rogercoll]

Wdyt if we move this defer calls to the t.Cleanup function? That way is aligned with the other resources rollback strategy, and we are also safe on panics.

[r0mdau]

I am unsure how to implement it as I see multiple options. I need to clean only if test.setECSMetadataURI is true. Because I find it handy to start the mock http server only if this same bool is true.

[rogercoll]

Makes sense to me, I think you could append the cleanup function inside the conditional. Something like:

			if test.setECSMetadataURI {
				server := startMockECSServer()
				os.Setenv("ECS_CONTAINER_METADATA_URI_V4", server.URL)
				t.Cleanup(func() {
					server.Close()
					os.Unsetenv("ECS_CONTAINER_METADATA_URI_V4")
				})
			}

[rogercoll]

Does the integration test interact with this server? Is it a dependency for gomaxecs.IsECS()?

[r0mdau]

For the gomaxecs library yes, it is making a http call to the ECS metadata uri.

Does it truly interacts ? I am not sure even for the github action CI, see my comment in the integration test PR.

Commands launched in Github action CI:

gotestsum --rerun-fails=1 --packages="./..." -- -race -timeout 360s -parallel 4 -skip Sudo -tags=integration,""
gotestsum --rerun-fails=1 --packages="./..." -- -race -timeout 360s -parallel 4 -skip Sudo -exec sudo -run Sudo -tags=integration,""

On my local workstation it is Skipped, compared to the github ci, I removed the -skip Sudo flag, the output:

$ cd extension/cgroupruntimeextension
$ ../../.tools/gotestsum --rerun-fails=1 --packages="./..." -- -race -timeout 360s -parallel 4 -tags=integration,""
∅  internal/metadata
✓  . (1.056s)

=== Skipped
=== SKIP: . TestCgroupV2SudoIntegration (0.00s)
    integration_test.go:48: System running in hybrid or cgroupv1 mode

DONE 15 tests, 1 skipped in 5.366s

I could run the tests in a docker container with some cgroups, open to any suggestion for making the integration test pass.

[rogercoll]

Could you help me identify where the gomaxecs library does the http call to the ECS metadata URI? I quickly checked the IsECS method and brought me to this GetECSMetadataURI method, which just looks for the environment variable.

I could run the tests in a docker container with some cgroups, open to any suggestion for making the integration test pass.

Nice catch, just pushed this small fix to make them run #36941

It seems that a changelog file is missing (make ch-new) and the linting CI is complaining. Could you please take a look?

Thanks!