Add a new CLI tool named golden (#39671)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description
Add a new CLI, golden, to run comparison of expected payloads over OTLP.

<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
Fixes #39662

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

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

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

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: atoulme

.chloggen/golden.yaml

@@ -0,0 +1,28 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: new_component
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: golden
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add a new CLI, golden, to run comparison of expected payloads over OTLP.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [39662]
+
+# (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: |
+  You can run golden with `--otlp-endpoint localhost:4317 --expected expected.yaml --write-expected --timeout 1m`
+
+# 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: []

.github/CODEOWNERS

@@ -18,6 +18,7 @@
 
 # Start components list
 
+cmd/golden/                                                      @open-telemetry/collector-contrib-approvers @atoulme
 cmd/opampsupervisor/                                             @open-telemetry/collector-contrib-approvers @evan-bradley @atoulme @tigrannajaryan
 cmd/otelcontribcol/                                              @open-telemetry/collector-contrib-approvers
 cmd/oteltestbedcol/                                              @open-telemetry/collector-contrib-approvers

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -18,6 +18,7 @@ body:
       # NOTE: The list below is autogenerated using `make generate-gh-issue-templates`
       # Do not manually edit it.
       # Start components list
+      - cmd/golden
       - cmd/opampsupervisor
       - cmd/otelcontribcol
       - cmd/oteltestbedcol

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -12,6 +12,7 @@ body:
       # NOTE: The list below is autogenerated using `make generate-gh-issue-templates`
       # Do not manually edit it.
       # Start components list
+      - cmd/golden
       - cmd/opampsupervisor
       - cmd/otelcontribcol
       - cmd/oteltestbedcol

.github/ISSUE_TEMPLATE/other.yaml

@@ -12,6 +12,7 @@ body:
       # NOTE: The list below is autogenerated using `make generate-gh-issue-templates`
       # Do not manually edit it.
       # Start components list
+      - cmd/golden
       - cmd/opampsupervisor
       - cmd/otelcontribcol
       - cmd/oteltestbedcol

.github/ISSUE_TEMPLATE/unmaintained.yaml

@@ -17,6 +17,7 @@ body:
       # NOTE: The list below is autogenerated using `make generate-gh-issue-templates`
       # Do not manually edit it.
       # Start components list
+      - cmd/golden
       - cmd/opampsupervisor
       - cmd/otelcontribcol
       - cmd/oteltestbedcol

.github/component_labels.txt

@@ -1,4 +1,5 @@
 # This file is auto-generated. Do not edit manually.
+cmd/golden cmd/golden
 cmd/opampsupervisor cmd/opampsupervisor
 cmd/otelcontribcol cmd/otelcontribcol
 cmd/oteltestbedcol cmd/oteltestbedcol

Makefile

@@ -444,6 +444,12 @@ opampsupervisor:
 	cd ./cmd/opampsupervisor && GO111MODULE=on CGO_ENABLED=0 $(GOCMD) build -trimpath -o ../../bin/opampsupervisor_$(GOOS)_$(GOARCH)$(EXTENSION) \
 		-tags $(GO_BUILD_TAGS) .
 
+# Build the golden executable.
+.PHONY: golden
+golden:
+	cd ./cmd/golden && GO111MODULE=on CGO_ENABLED=0 $(GOCMD) build -trimpath -o ../../bin/golden_$(GOOS)_$(GOARCH)$(EXTENSION) \
+		-tags $(GO_BUILD_TAGS) .
+
 MODULES="internal/buildscripts/modules"
 .PHONY: update-core-modules
 update-core-module-list:

cmd/golden/Makefile

@@ -0,0 +1 @@
+include ../../Makefile.Common

cmd/golden/README.md

@@ -0,0 +1,11 @@
+# Golden tester
+
+<!-- status autogenerated section -->
+| Status        |           |
+| ------------- |-----------|
+| Stability     | [alpha]: metrics   |
+| Issues        | [![Open issues](https://img.shields.io/github/issues-search/open-telemetry/opentelemetry-collector-contrib?query=is%3Aissue%20is%3Aopen%20label%3Acmd%2Fgolden%20&label=open&color=orange&logo=opentelemetry)](https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aopen+is%3Aissue+label%3Acmd%2Fgolden) [![Closed issues](https://img.shields.io/github/issues-search/open-telemetry/opentelemetry-collector-contrib?query=is%3Aissue%20is%3Aclosed%20label%3Acmd%2Fgolden%20&label=closed&color=blue&logo=opentelemetry)](https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aclosed+is%3Aissue+label%3Acmd%2Fgolden) |
+| [Code Owners](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/CONTRIBUTING.md#becoming-a-code-owner)    | [@atoulme](https://www.github.com/atoulme) |
+
+[alpha]: https://github.com/open-telemetry/opentelemetry-collector/blob/main/docs/component-stability.md#alpha
+<!-- end autogenerated section -->