[extension/cgroupruntime] Be aware of ECS task and CPU limits (#36920)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

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

<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
Fixes #36814 

<!--Describe what testing was performed and which tests were added.-->
#### Testing

Added integration test with `httptest` for the ECS metadata endpoint.

Something to clarify:
#36617 (comment)

<!--Describe the documentation added.-->
#### Documentation

Added extension name and link in the README.

<!--Please delete paragraphs that you did not use before submitting.-->

---------

Signed-off-by: Romain Dauby <[email protected]>
Co-authored-by: Roger Coll <[email protected]>

.chloggen/check-ecs-metadata-cgroupruntimeextension.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: cgroupruntimeextension
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Implement ECS metadata retrieval for cgroupruntime extension.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [36814]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

extension/cgroupruntimeextension/CONTRIBUTING.md

@@ -0,0 +1,26 @@
+# Contributing to the Cgroup Go runtime extension
+
+In order to contribute to this extension, it might be useful to have a working local setup.
+
+## Testing
+
+Some Linux distributions don't run systemd under cgroupv2, to run the integration tests locally for this extension you can follow these steps.
+
+Inside the extension folder, start a privileged docker container and share the code with the container
+
+```bash
+cd extension/cgroupruntimeextension
+docker run -ti --privileged --cgroupns=host -v $(pwd):/workspace -w /workspace debian:bookworm-slim
+```
+
+Install the [Go version](https://go.dev/dl/) specified in the extension's [go.mod](./go.mod) and the GCC compiler to run the integration test. The following is an example command for Go `1.23.4` in and `amd64` system:
+
+```bash
+apt update && apt install -y wget sudo gcc && wget https://go.dev/dl/go1.23.4.linux-amd64.tar.gz && tar -C /usr/local -xzf go1.23.4.linux-amd64.tar.gz && export PATH=$PATH:/usr/local/go/bin && go version && rm go1.23.4.linux-amd64.tar.gz
+```
+
+Run the integration test
+
+```bash
+CGO_ENABLED=1 go test -v -exec sudo -race -timeout 360s -parallel 4 -tags=integration,""
+```

extension/cgroupruntimeextension/README.md

@@ -15,7 +15,7 @@
 
 ## Overview
 
-The OpenTelemetry Cgroup Auto-Config Extension is designed to optimize Go runtime performance in containerized environments by automatically configuring GOMAXPROCS and GOMEMLIMIT based on the Linux cgroup filesystem. This extension leverages [automaxprocs](https://github.com/uber-go/automaxprocs) and [automemlimit](https://github.com/KimMachineGun/automemlimit) packages to dynamically adjust Go runtime variables, ensuring efficient resource usage aligned with container limits.
+The OpenTelemetry Cgroup Auto-Config Extension is designed to optimize Go runtime performance in containerized environments by automatically configuring GOMAXPROCS and GOMEMLIMIT based on the Linux cgroup filesystem. This extension leverages [automaxprocs](https://github.com/uber-go/automaxprocs) or [gomaxecs](https://github.com/rdforte/gomaxecs) for AWS ECS Tasks and [automemlimit](https://github.com/KimMachineGun/automemlimit) packages to dynamically adjust Go runtime variables, ensuring efficient resource usage aligned with container limits.
 
 ## Configuration
 
@@ -40,3 +40,7 @@ extension:
         enabled: true
         ratio: 0.8
 ```
+
+## Contributing
+
+See [CONTRIBUTING.md](CONTRIBUTING.md) for information on how to contribute to this extension.

extension/cgroupruntimeextension/factory.go

@@ -9,6 +9,7 @@ import (
 	"runtime/debug"
 
 	"github.com/KimMachineGun/automemlimit/memlimit"
+	gomaxecs "github.com/rdforte/gomaxecs/maxprocs"
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/extension"
 	"go.uber.org/automaxprocs/maxprocs"
@@ -42,10 +43,14 @@ func createExtension(_ context.Context, set extension.Settings, cfg component.Co
 	cgroupConfig := cfg.(*Config)
 	return newCgroupRuntime(cgroupConfig, set.Logger,
 		func() (undoFunc, error) {
-			undo, err := maxprocs.Set(maxprocs.Logger(func(str string, params ...any) {
+			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))
 			}))
-			return undoFunc(undo), err
 		},
 		func(ratio float64) (undoFunc, error) {
 			initial, err := memlimit.SetGoMemLimitWithOpts(memlimit.WithRatio(ratio))

extension/cgroupruntimeextension/go.mod

@@ -1,10 +1,11 @@
 module github.com/open-telemetry/opentelemetry-collector-contrib/extension/cgroupruntimeextension
 
-go 1.22.0
+go 1.22.4
 
 require (
 	github.com/KimMachineGun/automemlimit v0.7.0
 	github.com/containerd/cgroups/v3 v3.0.5
+	github.com/rdforte/gomaxecs v1.1.0
 	github.com/stretchr/testify v1.10.0
 	go.opentelemetry.io/collector/component v0.117.0
 	go.opentelemetry.io/collector/component/componenttest v0.117.0