用于 HTTP 状态 502 的 Traefik 自定义错误中间件不起作用

Question

我想为常见的 HTTP 错误代码提供自定义错误页面。我在关注this tutorial。为此，我创建了以下docker-compose.yml 文件来测试功能。它包括：

1. errorPageHandler 这是一个 nginx 服务器，能够返回静态 HTML 页面（404.html 和 502.html）。

2. whoami1将请求路由到traefik/whoami图像的80端口

3. whoami2 将请求路由到 traefik/whoami 图像的不存在端口 81，导致 502 - 网关错误

version: "3.7"

services:
  errorPageHandler:
    image: "nginx:latest"
    networks:
      - traefik-net
    volumes:
      - "./ErrorPages:/usr/share/nginx/ErrorPages"
      - "./default.conf:/etc/nginx/conf.d/default.conf"
    deploy:
      replicas: 1
      labels:
        # enable Traefik for this service
        - "traefik.enable=true"
        - "traefik.docker.network=traefik-net"

        # router (catches all requests with lowest possible priority)
        - "traefik.http.routers.error-router.rule=HostRegexp(`{catchall:.*}`)"
        - "traefik.http.routers.error-router.priority=1"
        - "traefik.http.routers.error-router.middlewares=error-pages-middleware"

        # middleware
        - "traefik.http.middlewares.error-pages-middleware.errors.status=400-599"
        - "traefik.http.middlewares.error-pages-middleware.errors.service=error-pages-service"
        - "traefik.http.middlewares.error-pages-middleware.errors.query=/{status}.html"

        # service
        - "traefik.http.services.error-pages-service.loadbalancer.server.port=80"
  
  whoami1:
    image: "traefik/whoami"
    networks:
      - traefik-net
    deploy:
      replicas: 1
      labels:
        # enable Traefik for this service
        - "traefik.enable=true"
        - "traefik.docker.network=traefik-net"

        # router
        - "traefik.http.routers.whoami1.rule=HostRegexp(`whoami1.local`)"
        - "traefik.http.routers.whoami1.service=whoami1"
        
        # service
        - "traefik.http.services.whoami1.loadbalancer.server.port=80"
        - "traefik.http.services.whoami1.loadbalancer.server.scheme=http"
        
  whoami2:
    image: "traefik/whoami"
    networks:
      - traefik-net
    deploy:
      replicas: 1
      labels:
        # enable Traefik for this service
        - "traefik.enable=true"
        - "traefik.docker.network=traefik-net"

        # router
        - "traefik.http.routers.whoami2.rule=HostRegexp(`whoami2.local`)"
        - "traefik.http.routers.whoami2.service=whoami2"
        
        # service
        - "traefik.http.services.whoami2.loadbalancer.server.port=81" # purposely wrong port
        - "traefik.http.services.whoami2.loadbalancer.server.scheme=http"

networks:
  traefik-net:
    external: true
    name: traefik-net

文件夹 ErrorPages 包含两个静态 HTML 文件，404.html 和 502.html。 default.conf的内容是：

server {
    listen       80;
    server_name  localhost;

    error_page  404    /404.html;
    error_page  502    /502.html;

    location / {
        root  /usr/share/nginx/ErrorPages;
        internal;
    }
}

我在我的hosts 文件中添加了以下条目（172.15.16.17 是部署了 Traefik 和所有提到的服务的服务器的 IP）：

172.15.16.17 error404.local
172.15.16.17 whoami1.local
172.15.16.17 whoami2.local

我的观察：

1. 当我访问 http://error404.local 时，Traefik 将请求路由到 nginx 并返回 404.html。这是预期行为，因为http://error404.local 与 Traefik 中定义的任何路由都不匹配。

2. 当我访问http://whoami1.local 时，Traefik 将请求路由到whoami1 服务，并在页面上显示有关容器的信息（预期行为）。

3. 当我访问http://whoami2.local 时，Traefik 不会将请求路由到 nginx 服务，但会显示其默认的Bad Gateway 页面。为什么不将请求路由到 nginx？

Answer 1

traefik 路由器（whoami1 和 whoami2）需要使用您定义的错误中间件

https://doc.traefik.io/traefik/middlewares/http/errorpages/ Traefik error middleware docs

所以将以下标签添加到各自的容器中

- "traefik.http.whoami1.middlewares=error-pages-middleware"

- "traefik.http.whoami2.middlewares=error-pages-middleware"

Traefik 仪表板将显示路由正在使用中间件（参考图片）One of my routes from my traefik dashboard

另一种选择是将中间件添加到入口点，以便所有路由都使用错误中间件（将此添加到 traefik 容器组合）

command:
  - "--entrypoints.websecure.address=:443"
  - "--entrypoints.websecure.http.middlewares=error-pages-middleware@docker"