Docker、Django和Selenium-Selenium无法连接

Question

我已经将Docker配置为使用docker-compose.yml运行Postgres和Django，它运行良好。

我遇到的问题是硒无法连接到Django直播服务器。

现在（至少对我来说）django必须访问selenium才能控制浏览器，而selenium必须访问django才能访问服务器。

我尝试使用docker大使模式，使用以下配置从这里docker-compose.yml：https://github.com/docker/compose/issues/666

postgis:
  dockerfile: ./docker/postgis/Dockerfile
  build: .
  container_name: postgis

django-ambassador:
  container_name: django-ambassador
  image: cpuguy83/docker-grand-ambassador
  volumes:
    - "/var/run/docker.sock:/var/run/docker.sock"
  command: "-name django -name selenium"

django:
  dockerfile: ./docker/Dockerfile-dev
  build: .
  command: python /app/project/manage.py test my-app
  container_name: django
  volumes:
    - .:/app
  ports:
    - "8000:8000"
    - "8081:8081"
  links:
    - postgis
    - "django-ambassador:selenium"
  environment:
    - SELENIUM_HOST=http://selenium:4444/wd/hub

selenium:
  container_name: selenium
  image: selenium/standalone-firefox-debug
  ports:
    - "4444:4444"
    - "5900:5900"
  links:
    - "django-ambassador:django"

当我检查时http://DOCKER-MACHINE-IP:4444/wd/hub/static/resource/hub.html我可以看到firefox启动了，但所有测试都失败了，因为firefox无法连接到django

'Firefox can't establish a connection to the server at localhost:8081'

我也在这里尝试了这个解决方案https://github.com/docker/compose/issues/1991但是这不起作用，因为我无法让django同时连接到postgis和selenium

'django.db.utils.OperationalError: could not translate host name "postgis" to address: Name or service not known'

我试着使用下面列出的网络功能

postgis:
  dockerfile: ./docker/postgis/Dockerfile
  build: .
  container_name: postgis
  net: appnet

django:
  dockerfile: ./docker/Dockerfile-dev
  build: .
  command: python /app/project/manage.py test foo
  container_name: django
  volumes:
    - .:/app
  ports:
    - "8000:8000"
    - "8081:8081"
  net: appnet
  environment:
    - SELENIUM_HOST=http://selenium:4444/wd/hub

selenium:
  container_name: selenium
  image: selenium/standalone-firefox-debug
  ports:
    - "4444:4444"
    - "5900:5900"
  net: appnet

但结果是一样的

'Firefox can't establish a connection to the server at localhost:8081'

那么，如何让selenium连接到django？

我已经玩了几天了-非常感谢任何帮助。

更多信息

另一件奇怪的事情是，当testserver运行时，如果我运行，则不使用docker（使用我以前的virtualenv配置等）/管理py test foo我可以通过以下位置的任何浏览器访问服务器：http://localhost:8081并获得服务的网页，但我无法访问测试服务器时，我运行等效的命令，如果我在docker下运行它。这很奇怪，因为我正在映射端口8081:8081-这有关系吗？

注意：我使用的是OSX和Docker v1.9.1

Answer 1

我也一直在努力解决这个问题，最终我找到了一个对我有效的解决方案。您可以尝试以下方式：

postgis:
  dockerfile: ./docker/postgis/Dockerfile
  build: .

django:
  dockerfile: ./docker/Dockerfile-dev
  build: .
  command: python /app/project/manage.py test my-app
  volumes:
    - .:/app
  ports:
    - "8000:8000"
  links:
    - postgis
    - selenium  # django can access selenium:4444, selenium can access django:8081-8100
  environment:
    - SELENIUM_HOST=http://selenium:4444/wd/hub
    - DJANGO_LIVE_TEST_SERVER_ADDRESS=django:8081-8100  # this gives selenium the correct address

selenium:
  image: selenium/standalone-firefox-debug
  ports:
    - "5900:5900"

我认为您不需要在selenium配置中包括端口4444。默认情况下，该端口是公开的，不需要将其映射到主机，因为django容器可以通过其到selenium容器的链接直接访问它。

[编辑]我发现您也不需要显式公开django容器的8081端口。此外，我为测试服务器使用了一系列端口，因为如果测试并行运行，您可能会收到“地址已在使用”错误，如下所述。

Answer 2

每当您看到localhost时，请先尝试端口转发该端口（在VM级别）

请参阅“从外部连接到docker容器内运行的服务”

VBoxManage controlvm "default" natpf1 "tcp-port8081,tcp,,8081,,8081"
VBoxManage controlvm "default" natpf1 "udp-port8081,udp,,8081,,8081"

（将默认替换为docker-Machine的名称：请参阅docker-Machine ls）

这与docker主机级别（基于boot2docker的Linux主机）的端口映射不同

OP luke aus在评论中确认：

输入网络的IP地址解决了问题！

Answer 3

我最终找到了一个更好的解决方案，不需要我硬编码IP地址。下面是我使用docker在django中运行测试时使用的配置。

# docker-compose base file for everything
version: '2'

services:
  postgis:
    build:
      context: .
      dockerfile: ./docker/postgis/Dockerfile
    container_name: postgis
    volumes:
      # If you are using boot2docker, postgres data has to live in the VM for now until #581 fixed
      # for more info see here: https://github.com/boot2docker/boot2docker/issues/581
      - /data/dev/docker_cookiecutter/postgres:/var/lib/postgresql/data

  django:
    build:
      context: .
      dockerfile: ./docker/django/Dockerfile
    container_name: django
    volumes:
      - .:/app
    depends_on:
      - selenium
      - postgis
    environment:
      - SITE_DOMAIN=django
      - DJANGO_SETTINGS_MODULE=settings.my_dev_settings
    links:
      - postgis
      - mailcatcher

  selenium:
    container_name: selenium
    image: selenium/standalone-firefox-debug:2.52.0
    ports:
      - "4444:4444"
      - "5900:5900"

ENTRYPOINT ["/docker/django/entrypoint.sh"]

#!/bin/bash
set -e

# Now we need to get the ip address of this container so we can supply it as an environmental
# variable for django so that selenium knows what url the test server is on
# Use below or alternatively you could have used
# something like "$@ --liveserver=$THIS_DOCKER_CONTAINER_TEST_SERVER"

if [[ "'$*'" == *"manage.py test"* ]]  # only add if 'manage.py test' in the args
then
  # get the container id
  THIS_CONTAINER_ID_LONG=`cat /proc/self/cgroup | grep 'docker' | sed 's/^.*\///' | tail -n1`
  # take the first 12 characters - that is the format used in /etc/hosts
  THIS_CONTAINER_ID_SHORT=${THIS_CONTAINER_ID_LONG:0:12}
  # search /etc/hosts for the line with the ip address which will look like this:
  #     172.18.0.4    8886629d38e6
  THIS_DOCKER_CONTAINER_IP_LINE=`cat /etc/hosts | grep $THIS_CONTAINER_ID_SHORT`
  # take the ip address from this
  THIS_DOCKER_CONTAINER_IP=`(echo $THIS_DOCKER_CONTAINER_IP_LINE | grep -o '[0-9]\+[.][0-9]\+[.][0-9]\+[.][0-9]\+')`
  # add the port you want on the end
  # Issues here include: django changing port if in use (I think)
  # and parallel tests needing multiple ports etc.
  THIS_DOCKER_CONTAINER_TEST_SERVER="$THIS_DOCKER_CONTAINER_IP:8081"
  echo "this docker container test server = $THIS_DOCKER_CONTAINER_TEST_SERVER"
  export DJANGO_LIVE_TEST_SERVER_ADDRESS=$THIS_DOCKER_CONTAINER_TEST_SERVER
fi


eval "$@"

SITE_DOMAIN = 'django'

docker-compose run django ./manage.py test