Docker container connection to gateway refused

Question

While setting up a php dev environment with docker, I ran into an issue while setting up remote debugging (XDEBUG) through a dbgp proxy.

Connecting my host machine to the proxy doesn't seem to be a problem, but the proxy container cannot reach my host machine over the port that is configured (in this case 9003)

I'm using docker compose on windows.

Sucessfully connecting my dev machine to the proxy:

INFO: dbgp.proxy: Server:onConnect ('172.18.0.1', 36558) [proxyinit -p 9003 -k XDEBUG_IDEA -m 1 ]

When executing a request containing the right IDE key (eg http://localhost/?XDEBUG_SESSION_START=XDEBUG_IDEA ), the proxy reacts correctly but is unable to contact the gateway over the port that was registered by my dev machine)

INFO: dbgp.proxy: connection from 172.18.0.2:40902 [<__main__.sessionProxy instance at 0x7fcff1998998>]
ERROR: dbgp.proxy: Unable to connect to the server listener 172.18.0.1:9003 [<__main__.sessionProxy instance at 0x7fcff1998998>]
Traceback (most recent call last):
  File "/usr/local/bin/pydbgpproxy", line 223, in startServer
    self._server.connect((self._serverAddr[0], self._serverAddr[1]))
  File "/usr/lib/python2.7/socket.py", line 224, in meth
    return getattr(self._sock,name)(*args)
error: [Errno 111] Connection refused
WARNING: dbgp.proxy: Unable to connect to server with key [XDEBUG_IDEA], stopping request [<__main__.sessionProxy instance at 0x7fcff1998998>]
INFO: dbgp.proxy: session stopped

Any ideas on what is going wrong here? Firewall issues can be excluded here, since i basically just turned it of.

I did log into the dbgpproxy container and was able to send requests to the gateway ip over ports 80 an 8080, but got the same connection refused when trying port 9003)

Any pointers would be greatly appreciated!

The docker compose file:

version: '2'

volumes:
  mysqldata:
    driver: local

services:

  app:
      restart: "always"
      image: php:7.0-fpm
      command: "true"
      volumes:
          - .:/var/www/html

  nginx:
      restart: "always"
      build: ./docker/nginx/
      ports:
          - "80:80"
      depends_on:
          - php

  php:
      restart: "always"
      build: ./docker/php/
      environment:
          XDEBUG_CONFIG: remote_host=dbgpproxy
      expose:
          - "9000"
      depends_on:
          - mysql
      volumes_from:
          - app

  composer:
    restart: "no"
    image: composer/composer:php7
    command: install
    volumes:
      - .:/app

  dbgpproxy:
    restart: "always"
    image: christianbladescb/dbgpproxy
    expose:
        - "9000"
    ports:
        - "9001:9001"
    environment:
        DOCKER_HOST: 10.0.75.1

  mysql:
      image: mysql:latest
      volumes:
          - mysqldata:/var/lib/mysql
      environment:
          MYSQL_ROOT_PASSWORD: secret
          MYSQL_DATABASE: project
          MYSQL_USER: project
          MYSQL_PASSWORD: project

  phpmyadmin:
      image: phpmyadmin/phpmyadmin
      ports:
          - 8080:80
      depends_on:
          - mysql
      environment:
          PMA_HOST: mysql

  redis:
    image: redis
    ports:
      - "6379:6379"

  mailcatcher:
      image: schickling/mailcatcher
      restart: "always"

Docker network info:

[
    {
        "Name": "test_default",
        "Id": "8f5b2e1188d65948d6a46977467b181e7fdb4b112a688ff87691b35c29da8970",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.18.0.0/16",
                    "Gateway": "172.18.0.1"
                }
            ]
        },
        "Internal": false,
        "Containers": {
            "05725540eca07666de250f2bb9ae856da69c0c325c4476150f214ba32a9b8714": {
                "Name": "test_nginx_1",
                "EndpointID": "723a820ea07e77cf976712293a911be3245e862477af6e0ecdcc1462536de6f5",
                "MacAddress": "02:42:ac:12:00:08",
                "IPv4Address": "172.18.0.8/16",
                "IPv6Address": ""
            },
            "78085ebed911e767a9c006d909cb245e0392055d37550c6cfa3a618969bef821": {
                "Name": "test_dbgpproxy_1",
                "EndpointID": "2332e1a01a8c0ec7262d96829d7d8f3cb4c711b6e9033ab85a8dfdb57ae01382",
                "MacAddress": "02:42:ac:12:00:0a",
                "IPv4Address": "172.18.0.10/16",
                "IPv6Address": ""
            },
            "7e12ea0a3a9b90360be6c15222fd052fbf02065aa18b8a3b12d19779bef4b41b": {
                "Name": "test_phpmyadmin_1",
                "EndpointID": "456a6508b6a507e01584beaf54eec9605db449261749065a562a6fb62111bb9c",
                "MacAddress": "02:42:ac:12:00:05",
                "IPv4Address": "172.18.0.5/16",
                "IPv6Address": ""
            },
            "81043a642cd9932e16bc51ba4604f6057d82e2c05f6e7378a85adfaa2de87f28": {
                "Name": "test_app_1",
                "EndpointID": "cfa41a5f210d4907747dcf7d516c6bdaecb817c993867a1e5f8e0250d33c927b",
                "MacAddress": "02:42:ac:12:00:03",
                "IPv4Address": "172.18.0.3/16",
                "IPv6Address": ""
            },
            "8b0cd7dc33fb783ae811f7ba15decd0165199da66242a10a33d8ee86c41bd664": {
                "Name": "test_mailcatcher_1",
                "EndpointID": "f2ed38e42dffd9565822a7ac248dcb022a47c8a78b05e93793b62d7188d0823c",
                "MacAddress": "02:42:ac:12:00:06",
                "IPv4Address": "172.18.0.6/16",
                "IPv6Address": ""
            },
            "d552bf1ab3914220b8fbf9961cc3801acbe180c6e945bd0b4c3bcf8588352a5d": {
                "Name": "test_mysql_1",
                "EndpointID": "6188cbeb49cf8afc2a7622bd6ef7fc7076ea91b909ec3efc1d9a1ed1d35d5790",
                "MacAddress": "02:42:ac:12:00:04",
                "IPv4Address": "172.18.0.4/16",
                "IPv6Address": ""
            },
            "ecc941fc337d727e3c118bf9112dee1552ef5db7c94b24706c7d03bc42ea6c0a": {
                "Name": "test_redis_1",
                "EndpointID": "3f4254982ed1be8354f514dd717993e02b4afdfad8d022f5f8daf0b919a852e1",
                "MacAddress": "02:42:ac:12:00:07",
                "IPv4Address": "172.18.0.7/16",
                "IPv6Address": ""
            },
            "f15f53405205db7263013fbb1ef1272764ca16850a46097b23d3619cd3d37b20": {
                "Name": "test_php_1",
                "EndpointID": "5fe30610823cd5660bf62e7612007ff4eef0316cbdfd15dbc0e56cafa6a3aca7",
                "MacAddress": "02:42:ac:12:00:02",
                "IPv4Address": "172.18.0.2/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]

Answer 1

That's because pydbgpproxy works similar to XDebug and it is trying to connect to the wrong IP address. The correct IP address pydbgpproxy should connect to is host.docker.internal.

Situation: xDebug ---> pydbgpproxy -X-> Host

This is because pydbgpproxy received the wrong IP from Docker in the first place. So I guess you have to hardcode the host.docker.internal IP into pydbgpproxy