services:
  otel-collector:
    image: otel/opentelemetry-collector-contrib:latest
    command: ["--config=/etc/otel-collector-config.yaml"]
    volumes:
      - ./otel-collector-config.yaml:/etc/otel-collector-config.yaml
    ports:
      - "4317:4317"   # OTLP gRPC (METRICS_URL target)
      - "4318:4318"   # OTLP HTTP
      - "8889:8889"   # collector's own Prometheus endpoint (received metrics)

  # Optional: scrape the collector's re-exposed metrics for a full local view.
  prometheus:
    image: prom/prometheus:latest
    volumes:
      - ./prometheus/prometheus.yml:/etc/prometheus/prometheus.yml
    ports:
      - "9090:9090"
    depends_on:
      - otel-collector