使用Traefik代理部分服务时出现502 Bad Gateway错误排查

我是Docker和Traefik新手，正在配置Traefik代理多个服务，部分服务可正常访问，但访问Pi-hole时出现502 Bad Gateway错误。通过https://myhost/nginx能正常获取Nginx测试页面，但访问https://myhost/pihole时加载5分钟后返回502错误。目前证书存在默认证书而非生产证书的问题，但推测与此无关。已通过Portainer确认Traefik、Pi-hole和Nginx处于同一网络“all_default”。以下是我的docker-compose.yml和Traefik配置文件，请求协助排查问题原因。

docker-compose.yml配置 #

version: '3'

services:
  portainer:
    image: portainer/portainer:latest
    ports:
      - "9000:9000"
    command:
      - --admin-password=<somePwd>
    networks:
      - local
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - portainer-data:/data

  traefik:
    image: "traefik:v2.5"
    container_name: "traefik"
    ports:
      - "80:80"
      - "443:443"
      # (Optional) Expose Dashboard
      - "8080:8080"  # Don't do this in production!
    volumes:
      - ./etc-traefik:/etc/traefik
      - /var/run/docker.sock:/var/run/docker.sock:ro
      - traefik-ssl-certs:/ssl-certs
    command:
      - --log.level=DEBUG
  
  nginx:
    image: nginx:latest
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.nginx.middlewares=nginx"
      - "traefik.http.middlewares.nginx.stripprefix.prefixes=/nginx"
      - "traefik.http.routers.nginx.entrypoints=web,websecure"
      - "traefik.http.routers.nginx.rule=Path(`/nginx`)"
      - "traefik.http.routers.nginx.tls=true"
      - "traefik.http.routers.nginx.tls.certresolver=production"

  pihole:
    container_name: pihole
    image: pihole/pihole:latest
    # For DHCP it is recommended to remove these ports and instead add: network_mode: "host"
    ports:
      - "53:53/tcp"
      - "53:53/udp"
    environment:
      TZ: 'Europe/Warsaw'
      DNS1: 127.0.0.1
      DNS2: 9.9.9.9
    volumes:
      - './etc-pihole:/etc/pihole'
      - './etc-dnsmasq.d:/etc/dnsmasq.d'
      - '/etc/resolv.conf:/etc/resolv.conf'
    restart: unless-stopped
    command:
      - --log.level=DEBUG
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.pihole.middlewares=pihole"
      - "traefik.http.middlewares.pihole.stripprefix.prefixes=/pihole"
      - "traefik.http.routers.pihole.entrypoints=web,websecure"
      - "traefik.http.routers.pihole.rule=Path(`/pihole`)"
      - "traefik.http.routers.pihole.tls=true"
      - "traefik.http.routers.pihole.tls.certresolver=production"
      - "traefik.port=80"
    
networks:
  local:
    driver: bridge

volumes:
  portainer-data:
  traefik-ssl-certs:
    driver: local

Traefik配置文件 #

global:
  checkNewVersion: true
  sendAnonymousUsage: false  # true by default

# (Optional) Enable API and Dashboard
# ---
api:
 dashboard: true  # true by default
 insecure: true  # Don't do this in production!

# Entry Points configuration
# ---
entryPoints:
  web:
    address: :80
    # (Optional) Redirect to HTTPS
    # ---
    http:
      redirections:
        entryPoint:
          to: websecure
          scheme: https

  websecure:
    address: :443

# Configure your CertificateResolver here...
# ---
certificatesResolvers:
  staging:
    acme:
      email: email@email
      storage: /etc/traefik/certs/acme.json
      caServer: "https://acme-staging-v02.api.letsencrypt.org/directory"
      httpChallenge:
        entryPoint: web

  production:
    acme:
      email: email@email
      storage: /etc/traefik/certs/acme.json
      caServer: "https://acme-v02.api.letsencrypt.org/directory"
      httpChallenge:
        entryPoint: web

providers:
  docker:
    exposedByDefault: false  # Default is true
  file:
    # watch for dynamic configuration changes
    directory: /etc/traefik
    watch: true

Portainer网络截图 #

内容的提问来源于stack exchange，提问作者skarembel