Add networkobservability_build_info Prometheus metric

[Copilot]

Description

Implements networkobservability_build_info metric following Prometheus build_info conventions. Metric exposes build metadata as labels with constant value of 1.

Implementation

• Metric: networkobservability_build_info{version="v0.0.17",architecture="amd64",os="linux"} 1
• Labels:
  • version: from buildinfo.Version (ldflags injection) with "unknown" fallback
  • architecture: from runtime.GOARCH
  • os: from runtime.GOOS
• Initialization: Single set during metrics.InitializeMetrics() at daemon startup

Code Changes

• pkg/metrics/types.go: BuildInfo gauge and BuildInfoDescription constant
• pkg/metrics/metrics.go: Metric creation and initialization with runtime values
• pkg/utils/metric_names.go: BuildInfoName constant
• pkg/utils/attr_utils.go: BuildVersion, BuildArchitecture, BuildOS label constants
• pkg/metrics/metrics_test.go: Test validation of metric value and labels

Related Issue

Addresses feature request for build info metric exposure.

Checklist

• I have read the contributing documentation.
• I signed and signed-off the commits (git commit -S -s ...). See this documentation on signing commits.
• I have correctly attributed the author(s) of the code.
• I have tested the changes locally.
• I have followed the project's style guidelines.
• I have updated the documentation, if necessary.
• I have added tests, if applicable.

Screenshots (if applicable) or Testing Completed

Metric output verified via test:

# HELP networkobservability_build_info Retina build information
# TYPE networkobservability_build_info gauge
networkobservability_build_info{architecture="amd64",os="linux",version="unknown"} 1

Unit tests pass with metric value and label validation.

Additional Notes

Version label uses "unknown" in test/dev builds. Production builds populate version via ldflags during build process.

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Please refer to the CONTRIBUTING.md file for more information on how to contribute to this project.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• https://api.github.com/repos/microsoft/retina/releases/latest
  • Triggering command: /usr/bin/curl curl -s REDACTED git conf�� G1dG6bKHw credential.usern-ifaceassert tnet/tools/bash (http block)
  • Triggering command: /usr/bin/curl curl -s REDACTED x64/pkg/include ortc�� x64/src/runtime/-p x64/src/internalgo.uber.org/zap (http block)
  • Triggering command: `/usr/bin/curl curl -s REDACTED ux_amd64/compileorigin -o crosoft-authentication-library-f-c=4 pkg/plugin/common/constants.go x64/pkg/tool/linux_amd64/compile-importcfg -p /informers/disco-V=full -lang=go1.23 x64/pkg/tool/linux_amd64/compileRename build info label constants to be more specific

Co-authored-by: nddq <28567936+nddq@users.noreply.github.com> -E th-securejoin@v0.5.1/deprecated_linux.go th-securejoin@v0.5.1/doc.go x64/pkg/tool/linux_amd64/compile entpools_client.git ild.go -imultiarch x64/pkg/tool/linux_amd64/compile` (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

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This section details on the original issue you should resolve

<issue_title>Prometheus metrics build info: retina_build_info</issue_title>
<issue_description>Is your feature request related to a problem? Please describe.
it's quite common to have a xxx_build_info metric that gives information about the application.

Describe the solution you'd like
Could you add a Prometheus metrics retina_build_info with some labels: version (git tag), architecture, ...

Describe alternatives you've considered

Additional context
</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Prometheus metrics build info: retina_build_info #338

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[github-actions]

Retina Code Coverage Report

Total coverage no change

Increased diff

Impacted Files	Coverage
pkg/metrics/metrics.go	43.25% ... 50.0% (6.75%)	⬆️