3/add opentelemetry prometheus and tempo support for repository

[crypto-a]

Summary of Changes

This pull request introduces a comprehensive observability stack and improves testing for the template-go project. These changes lay a solid foundation for future microservices by providing standardized tools for monitoring, tracing, and logging.

Key Features and Improvements

• Integrated Observability:

  • Prometheus: Added a Prometheus metric exporter to expose key metrics at the /metrics endpoint, allowing for easy monitoring and alerting.
  • OpenTelemetry & Tempo: Implemented OpenTelemetry tracing with an OTLP exporter, which is ready to send trace data to backends like Tempo. This enables distributed tracing to track requests across services.
  • Loki Correlation: The structured logger now automatically injects OpenTelemetry trace and span IDs into all log messages. This allows for seamless correlation of logs with traces in a centralized logging system like Loki.

• Enhanced Test Coverage:

  • The existing codebase now has 100% test coverage for its core components, including the HTTP router, logger, and OpenTelemetry initialization.
  • Added a new coverage target to the Makefile to generate and display coverage reports.

[Copilot]

Pull Request Overview

This pull request introduces a comprehensive observability stack by integrating OpenTelemetry with Prometheus metrics and OTLP tracing support, while consolidating logger functionality and achieving 100% test coverage for core components.

• Refactored logger package to consolidate functionality and add OpenTelemetry trace injection
• Implemented OpenTelemetry initialization with both metrics (Prometheus) and tracing (OTLP) exporters
• Added comprehensive test coverage for all core components including HTTP router, logger, and OpenTelemetry setup

Reviewed Changes

Copilot reviewed 15 out of 18 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
pkg/logger/logger.go	Consolidated logging functions with OpenTelemetry trace injection
pkg/logger/levels.go	Removed - functions moved to main logger file
pkg/logger/otel.go	Removed - trace injection moved to main logger file
pkg/logger/logger_test.go	Added comprehensive test coverage for logger functionality
internal/otel/open_telemetry.go	New OpenTelemetry setup with both metrics and tracing
internal/otel/setup.go	Removed - replaced by enhanced open_telemetry.go
internal/otel/open_telemetry_test.go	Added comprehensive test coverage for OpenTelemetry initialization
internal/delivery/http/router.go	Added OpenTelemetry middleware and updated to accept service name
internal/delivery/http/router_test.go	Added test coverage for HTTP router functionality
internal/delivery/http/routes/root_test.go	Added test coverage for root route handlers
internal/config/config_test.go	Added test coverage for configuration loading
cmd/template-go/main.go	Updated to use new OpenTelemetry initialization
Makefile	Added coverage target with exclusions
tests/config.yaml	Added test configuration for coverage exclusions
go.mod	Updated dependencies for testing and OpenTelemetry metrics

Comments suppressed due to low confidence (1)

go.mod:3

• Go version 1.24.4 does not exist. The latest Go version as of January 2025 was 1.23.x. Please use a valid Go version.

go 1.24.4

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[Copilot]

Pull Request Overview

Copilot reviewed 15 out of 18 changed files in this pull request and generated no new comments.

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[Copilot]

Pull Request Overview

Copilot reviewed 15 out of 18 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (1)

go.mod:3

• Go version 1.24.4 does not exist. The latest Go version as of my knowledge cutoff is 1.23.x. Please use a valid Go version.

go 1.24.4

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[MatteoGentili24]

Approved.