Proxy error with multiple docker network on local environment

[giuseppeiannelli]

Hi,

I setup two network: frontend and backend into docker-compose.yml

version: '2.3'

networks:
  backend:
  frontend:

volumes:
  varlibldap:
    driver: local
  etcldapslapdd:
    driver: local
  varwwwphpldapadmin:
    driver: local

services:

  traefik:
    image: traefik:2.2
    networks:
      frontend:
    ports:
      - "80:80"
      - "8080:8080"
      - "443:443"
    command:
      - "--api.insecure=true"
      - "--accesslog=true"
      - "--providers.docker.exposedByDefault=false"
      - "--entryPoints.http.address=:80"
      - "--entryPoints.https.address=:443"
      - "--log.level=DEBUG"
      - "--providers.docker"
      - "--providers.docker.network=frontend"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock

  ldap:
    image: osixia/openldap:1.3.0
    hostname: ldap.docker.local
    networks:
      backend:
    environment:
      LDAP_ORGANISATION: "ACME Inc."
      LDAP_DOMAIN: "corp.acme.com"
      LDAP_ADMIN_PASSWORD: "JonSn0w"
      LDAP_TLS: 'true'
    volumes:
      - varlibldap:/var/lib/ldap
      - etcldapslapdd:/etc/ldap/slapd.d

  phpldapadmin:
    image: osixia/phpldapadmin:0.9.0
    hostname: phpldapadmin.docker.local
    networks:
      frontend:
        aliases: 
          - phpldapadmin.docker.local
      backend:
    environment:
      PHPLDAPADMIN_LDAP_HOSTS: ldap
      PHPLDAPADMIN_HTTPS: 'false'
    volumes:
      - varwwwphpldapadmin:/var/www/phpldapadmin
    labels:
      - "traefik.enable=true"
      - "traefik.docker.network=frontend"
      # http entrypoint
      - "traefik.http.middlewares.phpldapadmin-http2https.redirectscheme.permanent=true"
      - "traefik.http.middlewares.phpldapadmin-http2https.redirectscheme.scheme=https"
      - "traefik.http.routers.phpldapadmin-http.entryPoints=http"
      - "traefik.http.routers.phpldapadmin-http.rule=Host(`phpldapadmin.docker.local`)"
      - "traefik.http.routers.phpldapadmin-http.middlewares=phpldapadmin-http2https"
      # https entrypoint
      - "traefik.http.routers.phpldapadmin-https.entryPoints=https"
      - "traefik.http.routers.phpldapadmin-https.rule=Host(`phpldapadmin.docker.local`)"
      - "traefik.http.routers.phpldapadmin-https.service=phpldapadmin-https"
      - "traefik.http.routers.phpldapadmin-https.tls=true"
      - "traefik.http.services.phpldapadmin-https.loadbalancer.passhostheader=true"
      - "traefik.http.services.phpldapadmin-https.loadbalancer.server.port=80"
      - "traefik.http.services.phpldapadmin-https.loadbalancer.server.scheme=http"

Both traefik and phpldapadmin containers are in the same network as showed below:

❯ docker network inspect ldap_frontend
[
    {
        "Name": "ldap_frontend",
        "Id": "d84a4c4dfaf229bd68b33ec1eee21d43d4f8631cd3aaf6788d37c799e9422d48",
        "Created": "2020-03-28T12:32:16.752088842Z",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.20.0.0/16",
                    "Gateway": "172.20.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": true,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "48ad2ff71b46d7c1c8a742366e683eb24d55ad36792c6268fec439296143b267": {
                "Name": "ldap_phpldapadmin_1",
                "EndpointID": "c288b66d01eccf90f79fef07aaba4874f0f7a3817521a1c86d244ca88a26cb43",
                "MacAddress": "02:42:ac:14:00:02",
                "IPv4Address": "172.20.0.2/16",
                "IPv6Address": ""
            },
            "df8352145f9307d09579d5745411abc51d786f627aa04ea21ba1d70d4c87fac3": {
                "Name": "ldap_traefik_1",
                "EndpointID": "458c136de2b4ea35ce0d5fdaa44dbeb26df71efaf82d0eb7ba1ac9e0d4bbc38c",
                "MacAddress": "02:42:ac:14:00:03",
                "IPv4Address": "172.20.0.3/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {
            "com.docker.compose.network": "frontend",
            "com.docker.compose.project": "ldap",
            "com.docker.compose.version": "1.25.4"
        }
    }
]

❯ docker network inspect ldap_backend
[
    {
        "Name": "ldap_backend",
        "Id": "210404e96a48fae8bc0fc689f834133c619f56d91e0d07511ae59599adc6d199",
        "Created": "2020-03-28T12:32:16.795605381Z",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.21.0.0/16",
                    "Gateway": "172.21.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": true,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "48ad2ff71b46d7c1c8a742366e683eb24d55ad36792c6268fec439296143b267": {
                "Name": "ldap_phpldapadmin_1",
                "EndpointID": "98f3d4a93c01c9ad9db5e1d4eacdf2bdff003a51c314d1bbd74178a0544b67c4",
                "MacAddress": "02:42:ac:15:00:03",
                "IPv4Address": "172.21.0.3/16",
                "IPv6Address": ""
            },
            "dea2ed5f1185353775d37c762e03812cbbf9ed91162a4be8d3f7b1b65faa7eec": {
                "Name": "ldap_ldap_1",
                "EndpointID": "195048371e1dbd131cbf2d0c8a6f432feb90228bd981ded04592a862a570cb9e",
                "MacAddress": "02:42:ac:15:00:02",
                "IPv4Address": "172.21.0.2/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {
            "com.docker.compose.network": "backend",
            "com.docker.compose.project": "ldap",
            "com.docker.compose.version": "1.25.4"
        }
    }
]

When I check traefik logs, I found that traefik use backend network to proxy on phpldapadmin:

traefik_1 | 172.20.0.1 - - [28/Mar/2020:12:32:56 +0000] "GET / HTTP/2.0" 504 15 "-" "-" 1 "phpldapadmin-https@docker" "http://172.21.0.3:80" 30006ms

I have configured traefik to use only the frontend network, so how is it possible that traefik tries to use the backend network?

This problem has been encountered with both version 2.1 and 2.2 of traefik.

[ldez]

Hello,

It's not the good place for this issue.

• https://community.containo.us/
• https://github.com/containous/traefik