Exporter

Prometheus가 Pull할 수 있도록 메트릭을 /metrics 엔드포인트로 노출하는 컴포넌트

공통 컨벤션

• 네트워크: monitoring_net
• Prometheus prometheus.yml에 서비스명:포트로 타깃 등록
• 검증: curl http://<container>:<port>/metrics

1. node-exporter (호스트 OS)

호스트의 CPU/RAM/디스크/온도를 /metrics에 노출

services:
  node-exporter:
    image: prom/node-exporter:v1.8.2
    container_name: node-exporter
    command:
      - '--path.rootfs=/host'
    pid: host
    volumes:
      - '/:/host:ro,rslave'
    restart: unless-stopped
    networks:
      - monitoring_net

Prometheus 타깃:

- job_name: 'host'
  static_configs:
    - targets: ['node-exporter:9100']

• 포트: 9100
• 커스텀 메트릭: --collector.textfile.directory 옵션으로 텍스트파일 컬렉터 추가 가능

2. cAdvisor (컨테이너)

도커 컨테이너별 CPU/메모리/재시작 수를 /metrics 노출

services:
  cadvisor:
    image: gcr.io/cadvisor/cadvisor:v0.49.2
    container_name: cadvisor
    privileged: true
    volumes:
      - /:/rootfs:ro
      - /var/run:/var/run:ro
      - /sys:/sys:ro
      - /var/lib/docker/:/var/lib/docker:ro
    restart: unless-stopped
    networks:
      - monitoring_net

Prometheus 타깃:

- job_name: 'containers'
  static_configs:
    - targets: ['cadvisor:8080']

• 포트: 8080
• rootless 환경에서 권한 문제 시 privileged: true 또는 마운트 경로 점검

3. blackbox-exporter (HTTP/TCP/ICMP 프로브)

프로브 대상을 파라미터로 받아 가용성 체크

services:
  blackbox:
    image: prom/blackbox-exporter:v0.25.0
    container_name: blackbox
    volumes:
      - ./blackbox.yml:/etc/blackbox_exporter/config.yml:ro
    command:
      - '--config.file=/etc/blackbox_exporter/config.yml'
    restart: unless-stopped
    networks:
      - monitoring_net

blackbox.yml:

modules:
  http_2xx:
    prober: http
    timeout: 10s
    http:
      method: GET
      valid_status_codes: [200, 302]
      preferred_ip_protocol: "ip4"

  tcp_connect:
    prober: tcp
    timeout: 5s

Prometheus 타깃 (HTTP 헬스체크):

- job_name: 'api-probe'
  metrics_path: /probe
  params:
    module: [http_2xx]
  static_configs:
    - targets:
      - http://api:3000/health
  relabel_configs:
    - source_labels: [__address__]
      target_label: __param_target
    - target_label: instance
      replacement: api
    - target_label: __address__
      replacement: blackbox:9115

• 포트: 9115
• metrics_path: /probe + relabel_configs 패턴 필수

4. mysqld_exporter (선택)

MySQL 연결/쿼리율/슬로우쿼리 등

services:
  mysqld-exporter:
    image: prom/mysqld-exporter:v0.15.1
    container_name: mysqld-exporter
    environment:
      DATA_SOURCE_NAME: 'exporter:password@(db:3306)/'
    restart: unless-stopped
    networks:
      - monitoring_net

MySQL 최소 권한 설정:

CREATE USER 'exporter'@'%' IDENTIFIED BY 'password';
GRANT PROCESS, REPLICATION CLIENT, SELECT ON *.* TO 'exporter'@'%';
FLUSH PRIVILEGES;

• 포트: 9104
• 보안: 환경변수 대신 Docker secrets 권장

5. redis_exporter (선택)

Redis 메모리/키/evicted keys/AOF/RDB 상태

services:
  redis-exporter:
    image: oliver006/redis_exporter:v1.62.0
    container_name: redis-exporter
    environment:
      REDIS_ADDR: 'redis://redis:6379'
      # REDIS_PASSWORD: 'yourpass'
    restart: unless-stopped
    networks:
      - monitoring_net

• 포트: 9121

전체 compose 스니펫 (필요한 것만 선택)

services:
  node-exporter:
    image: prom/node-exporter:v1.8.2
    command: ['--path.rootfs=/host']
    pid: host
    volumes: ['/:/host:ro,rslave']
    networks: [monitoring_net]
    restart: unless-stopped

  cadvisor:
    image: gcr.io/cadvisor/cadvisor:v0.49.2
    privileged: true
    volumes:
      - /:/rootfs:ro
      - /var/run:/var/run:ro
      - /sys:/sys:ro
      - /var/lib/docker/:/var/lib/docker:ro
    networks: [monitoring_net]
    restart: unless-stopped

  blackbox:
    image: prom/blackbox-exporter:v0.25.0
    volumes:
      - ./blackbox.yml:/etc/blackbox_exporter/config.yml:ro
    networks: [monitoring_net]
    restart: unless-stopped

  mysqld-exporter:
    image: prom/mysqld-exporter:v0.15.1
    environment:
      DATA_SOURCE_NAME: 'exporter:password@(db:3306)/'
    networks: [monitoring_net]
    restart: unless-stopped

  redis-exporter:
    image: oliver006/redis_exporter:v1.62.0
    environment:
      REDIS_ADDR: 'redis://redis:6379'
    networks: [monitoring_net]
    restart: unless-stopped

networks:
  monitoring_net:
    driver: bridge

보안 팁

• 외부 포트 노출 최소화: Prometheus만 내부 네트워크에서 접근
• node-exporter: 호스트 마운트 read-only 유지
• mysqld_exporter/redis_exporter: 최소 권한 계정 사용

관련 개념

• Prometheus - 수집 타깃 설정
• PromQL - 메트릭 조회
• Monitoring - 전체 흐름