Phần 3 — Grafana Alloy: Collector duy nhất cho metrics, logs, traces

services:
  alloy:
    image: grafana/alloy:v1.15.1
    environment:
      - HOSTNAME={{.Node.Hostname}}
    volumes:
      - ./config/config.alloy:/etc/alloy/config.alloy:ro
      - /var/lib/docker/containers:/var/lib/docker/containers:ro
      - /var/run/docker.sock:/var/run/docker.sock:ro
      - /:/host/root:ro,rslave
      - /sys:/host/sys:ro
      - /proc:/host/proc:ro
    command:
      - run
      - --server.http.listen-addr=0.0.0.0:12345
      - --storage.path=/var/lib/alloy/data
      - /etc/alloy/config.alloy
    ports:
      - "4317:4317"   # OTLP gRPC
      - "4318:4318"   # OTLP HTTP
      - "12345:12345" # Alloy UI
    networks: [observability-net]
    deploy:
      mode: global
      resources:
        limits: { memory: 512M }
      update_config:
        parallelism: 1
        delay: 10s
        order: stop-first

networks:
  observability-net:
    external: true

// =====================================================
// 1. DESTINATIONS
// =====================================================

// Metrics → Mimir
prometheus.remote_write "mimir" {
  endpoint {
    url = "http://mimir:8080/api/v1/push"
    headers = { "X-Scope-OrgID" = "primary_cluster" }
  }
}

// Logs → Loki
loki.write "loki" {
  endpoint { url = "http://loki:3100/loki/api/v1/push" }
  external_labels = { cluster = "primary_cluster" }
}

// Traces → Tempo
otelcol.exporter.otlp "tempo" {
  client {
    endpoint = "tempo:4317"
    tls { insecure = true }
  }
}

// =====================================================
// 2. METRICS — node + cAdvisor (containers)
// =====================================================

prometheus.exporter.unix "node" {
  rootfs_path = "/host/root"
  sysfs_path  = "/host/sys"
  procfs_path = "/host/proc"
}

prometheus.scrape "node_exporter" {
  targets    = prometheus.exporter.unix.node.targets
  forward_to = [prometheus.remote_write.mimir.receiver]
  scrape_interval = "30s"
}

prometheus.exporter.cadvisor "containers" {
  docker_host = "unix:///var/run/docker.sock"
}

prometheus.scrape "cadvisor" {
  targets    = prometheus.exporter.cadvisor.containers.targets
  forward_to = [prometheus.remote_write.mimir.receiver]
  scrape_interval = "30s"
}

// =====================================================
// 3. LOGS — Docker container logs
// =====================================================

discovery.docker "containers" {
  host = "unix:///var/run/docker.sock"
}

loki.source.docker "logs" {
  host       = "unix:///var/run/docker.sock"
  targets    = discovery.docker.containers.targets
  forward_to = [loki.process.relabel.receiver]
}

loki.process "relabel" {
  forward_to = [loki.write.loki.receiver]
  stage.docker { }
  stage.labels {
    values = {
      stack   = "__meta_docker_swarm_service_label_com_docker_stack_namespace",
      service = "__meta_docker_swarm_service_name",
      node    = "__meta_docker_host",
    }
  }
}

// =====================================================
// 4. OTLP RECEIVER — apps push trực tiếp
// =====================================================

otelcol.receiver.otlp "app" {
  grpc { endpoint = "0.0.0.0:4317" }
  http { endpoint = "0.0.0.0:4318" }
  output {
    metrics = [otelcol.processor.batch.default.input]
    traces  = [otelcol.processor.batch.default.input]
    logs    = [otelcol.processor.batch.default.input]
  }
}

otelcol.processor.batch "default" {
  output {
    metrics = [otelcol.exporter.prometheus.mimir_bridge.input]
    traces  = [otelcol.exporter.otlp.tempo.input]
    logs    = [otelcol.exporter.loki.loki_bridge.input]
  }
}

otelcol.exporter.prometheus "mimir_bridge" {
  forward_to = [prometheus.remote_write.mimir.receiver]
}

otelcol.exporter.loki "loki_bridge" {
  forward_to = [loki.write.loki.receiver]
}

docker network create -d overlay observability-net
docker stack deploy -c alloy-compose.yml obs