Feature | Add middleware for OpenTelemetry

[matiasperrone-exo]

Overview

This PR adds comprehensive OpenTelemetry (OTEL) middleware integration to the IdP API, enabling distributed tracing, metrics collection, and centralized logging through OTLP (OpenTelemetry Protocol).

Key Features

• Request Tracking Middleware: TrackRequestMiddleware that captures request/response metadata including timing, CloudFlare Ray ID, and baggage context
• OpenTelemetry Integration: Full integration with keepsuit/laravel-opentelemetry package (v1.14)
• Trace Context Propagation: Support for W3C Trace Context and Baggage standards
• OTEL Collector Stack: Docker Compose configuration with OpenTelemetry Collector and Elasticsearch backend
• Configurable Exporters: Support for OTLP gRPC, OTLP HTTP, and Zipkin exporters
• Elasticsearch Storage: Centralized logging and trace storage in Elasticsearch
• Performance Monitoring: Response time tracking and HTTP status code attributes
• Instrumentation: Pre-configured instrumentations for HTTP, database queries, Redis, queues, cache, events, views, and console commands

Files Added

• app/Http/Middleware/TrackRequestMiddleware.php - Request/response tracking middleware
• config/opentelemetry.php - OpenTelemetry configuration file
• docker-compose/opentelemetry/otel-collector-config.yaml - OTEL Collector configuration
• .env.example - Updated with OpenTelemetry environment variables

Files Modified

• app/Http/Kernel.php - Added TrackRequestMiddleware to middleware stack
• composer.json - Added OpenTelemetry dependencies and PSR-compatible autoloaders
• composer.lock - Updated dependencies
• docker-compose.yml - Added Elasticsearch and OpenTelemetry Collector services

Configuration Highlights

Environment Variables

• OTEL_SERVICE_ENABLED - Enable/disable OpenTelemetry
• OTEL_SERVICE_NAME - Service name (defaults to app name)
• OTEL_EXPORTER_OTLP_ENDPOINT - Collector endpoint (default: http://otel-collector:4318)
• OTEL_EXPORTER_OTLP_PROTOCOL - Protocol: grpc, http/protobuf, http/json
• OTEL_TRACES_SAMPLER_TYPE - Sampler: always_on, always_off, traceidratio
• OTEL_INSTRUMENTATION_* - Toggle individual instrumentations

Docker Services

• OpenTelemetry Collector: Receives traces, metrics, logs via OTLP
• Elasticsearch: Stores traces, metrics, logs for analysis
• Ports: 4318 (OTLP HTTP), 4317 (OTLP gRPC), 9200 (Elasticsearch), 8888/8889 (Prometheus)

Architecture

• TrackRequestMiddleware: Runs early in middleware stack to track request lifecycle
• Baggage Context: CloudFlare Ray ID and User-Agent propagated via OpenTelemetry Baggage
• Span Lifecycle: Events for request start/finished with duration and status
• Graceful Degradation: Disabled in testing environment
• Error Handling: Comprehensive error logging without breaking request flow

Dependencies Added

• keepsuit/laravel-opentelemetry ^1.14 - Laravel OpenTelemetry wrapper
• open-telemetry/api ^1.4 - OTEL API
• open-telemetry/sdk ^1.9 - OTEL SDK
• open-telemetry/exporter-otlp ^1.3 - OTLP exporter
• google/protobuf ^4.33 - Protocol Buffers support
• composer/semver ^3.4.4 - Version constraint handling

Task:

Ref: https://app.clickup.com/t/86b7ccrnm

[matiasperrone-exo]

@smarcet please review again as all the requested changes were incorporated.