Docker Swarm中Traefik代理SonarQube返回404如何正确配置？

核心问题点 #

• Swarm模式下Traefik识别的服务标签必须放在deploy.labels字段下，直接放在服务根的labels不会被Traefik读取，这是返回404的最主要原因
• Traefik v2.x 不支持旧版traefik.port配置，需要用服务负载均衡端口配置替代
• Host规则的引号使用不规范，YAML中内嵌单引号会出现解析错误，推荐用反引号包裹域名
• Traefik服务缺少Swarm专属部署约束，无法保证在集群中正常读取服务元数据

修正后的配置 #

1. swarm.yml 配置 #

version: "3.7"

services:
  traefik:
    image: "traefik:v2.1"
    networks:
      - traefik-public
    ports:
      - "80:8"
      - "8080:8080"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro
      - ./traefik.yml:/traefik.yml:ro
    deploy:
      # 必须部署在Swarm管理节点才能读取docker.sock元数据
      placement:
        constraints:
          - node.role == manager

  sonar:
    image: sonarqube:8.9-community
    networks:
      - pg-net
      - traefik-public
    # 走Traefik代理无需暴露端口到主机，可注释删除
    # ports:
    #  - "9000:9000"
    environment:
      - SONAR_JDBC_URL=jdbc:postgresql://sqdb:5432/sonarqube
      - SONAR_JDBC_USERNAME=sonarqube
      - SONAR_JDBC_PASSWORD=N1eC7ALj1P1bOf4!wyhQi
    deploy:
      labels:
        - "traefik.enable=true"
        - "traefik.docker.network=traefik-public"
        - "traefik.http.routers.sonar.entrypoints=web"
        - "traefik.http.routers.sonar.rule=Host(`sonar.example.com`)"
        - "traefik.http.services.sonar.loadbalancer.server.port=9000"
    
networks:
  traefik-public:
    external: true
  # 若pg-net不是外部网络请补充配置
  pg-net:
    external: true

2. traefik.yml 优化配置 #

## STATIC CONFIGURATION
log:
  level: INFO

api:
  insecure: true
  dashboard: true

entryPoints:
  web:
    address: ":80"

providers:
  docker:
    endpoint: "unix:///var/run/docker.sock"
    exposedByDefault: false
    swarmMode: true
    # 新增：Swarm服务状态刷新间隔，单位秒
    swarmModeRefreshSeconds: 10
    # 新增：默认代理网络，后续服务无需重复配置traefik.docker.network
    defaultNetwork: traefik-public

部署验证步骤 #

• 先确认traefik-public是Swarm范围的overlay网络：docker network ls | grep traefik-public，若不存在执行docker network create --driver=overlay --scope=swarm traefik-public创建
• 用stack命令部署：docker stack deploy -c swarm.yml service-stack
• 访问集群任意节点的8080端口打开Traefik Dashboard，确认HTTP路由列表中已存在sonar路由
• 本地配置hosts将sonar.example.com指向集群任意节点IP，访问即可正常打开SonarQube
• 后续新增服务仅需在对应服务的deploy.labels下配置Traefik路由规则即可，无需修改Traefik本身配置

内容的提问来源于stack exchange，提问作者Andrews Karaban