Question

我已经浏览了this answer，但无法弄清楚如何将其应用于我的问题，因此，如果答案是正确的，将不胜感激。

我也是docker和docker-compose的菜鸟。

我有一个简单的docker-compose.yml

version: '3'

services:
  redis:
    image: "redis:alpine"
  web:
    build: . # current directory
    command: bash -c "python /app/src/manage.py migrate && 
                      python /app/src/manage.py runserver 0.0.0.0:8000"
    volumes: 
      - .:/app
    ports:
      - "8000:8000"

当我使用docker-compose up运行此命令时，一切似乎都正常：

$ docker-compose up
Starting hackerspace_redis_1 ... 
Starting hackerspace_redis_1 ... done
Starting hackerspace_web_1 ... 
Starting hackerspace_web_1 ... done
Attaching to hackerspace_redis_1, hackerspace_web_1
redis_1  | 1:C 19 Jul 2019 16:49:10.644 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
redis_1  | 1:C 19 Jul 2019 16:49:10.644 # Redis version=5.0.5, bits=64, commit=00000000, modified=0, pid=1, just started
redis_1  | 1:C 19 Jul 2019 16:49:10.644 # Warning: no config file specified, using the default config. In order to specify a config file use redis-server /path/to/redis.conf
redis_1  | 1:M 19 Jul 2019 16:49:10.645 * Running mode=standalone, port=6379.
redis_1  | 1:M 19 Jul 2019 16:49:10.645 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
redis_1  | 1:M 19 Jul 2019 16:49:10.645 # Server initialized
redis_1  | 1:M 19 Jul 2019 16:49:10.645 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
redis_1  | 1:M 19 Jul 2019 16:49:10.645 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
redis_1  | 1:M 19 Jul 2019 16:49:10.645 * DB loaded from disk: 0.000 seconds
redis_1  | 1:M 19 Jul 2019 16:49:10.645 * Ready to accept connections
web_1    | Operations to perform:
web_1    |   Apply all migrations: account, admin, announcements, auth, badges, comments, contenttypes, courses, django_summernote, djconfig, djcytoscape, flatpages, notifications, portfolios, prerequisites, profile_manager, quest_manager, sessions, sites, socialaccount, suggestions, utilities
web_1    | Running migrations:
web_1    |   No migrations to apply.
web_1    | Performing system checks...
web_1    | 
web_1    | System check identified no issues (0 silenced).
web_1    | July 19, 2019 - 09:49:16
web_1    | Django version 2.0.13, using settings 'hackerspace_online.settings'
web_1    | Starting development server at http://0.0.0.0:8000/
web_1    | Quit the server with CONTROL-C.

我可以通过127.0.0.0:8000的浏览器访问django应用。但是，当我尝试登录该应用程序时，我得到：

/ accounts / login /
处的ConnectionError
错误111连接到127.0.0.1:6379。连接被拒绝。

这是我在Django设置中连接到Redis的方式：

REDIS_HOST = os.environ.get('REDIS_HOST', '127.0.0.1')
REDIS_PORT = os.environ.get('REDIS_PORT', '6379')

CACHES = {
    "default": {
        "BACKEND": "django_redis.cache.RedisCache",
        "LOCATION": "redis://{}:{}/1".format(REDIS_HOST, REDIS_PORT),
        "OPTIONS": {
            "CLIENT_CLASS": "django_redis.client.DefaultClient",
        }
    },
    #...
}

如何使django应用连接到Redis容器？

请注意，据我所知，使用端口6379（通过sudo lsof -i -P -n | grep LISTEN）没有其他用途

Answer 1

Docker中的

127.0.0.1几乎总是表示“此容器”。如果您是在Docker Compose下运行应用程序，那么它会

...为您的应用设置单个网络。服务的每个容器都加入默认网络，并且在该网络上的其他容器都可以可访问，在与该容器名称相同的主机名下，它们也可以可发现。

也就是说，在此docker-compose.yml文件的上下文中，有主机名redis和web指向两个容器。

您已经完成了重要的配置工作之一。当您的代码说

REDIS_HOST = os.environ.get('REDIS_HOST', '127.0.0.1')

您可以设置一个覆盖内置默认值的环境变量。因此，这里您只需要在docker-compose.yml文件中添加环境变量设置即可：

version: '3'
services:
  redis:
    image: "redis:alpine"
  web:
    build: . # current directory
    environment:
      - REDIS_HOST=redis
    ports:
      - "8000:8000"
    # application source code and default command are built into the image

Answer 2

如果您使用的是docker-compose，则需要引用容器的名称（即redis）而不是本地主机。 Localhost是每个容器，docker-compose将连接隐式网络上的每个容器，它们需要为其解析名称。将它们视为独立的机器。在配置网络时，它有助于获得视角。因此，您尝试连接到Redis的快速调整应该可以解决问题。

文档https://docs.docker.com/compose/networking/描述了在您未明确创建默认网络时如何创建默认网络。

docker-compose + django + redis-错误111连接到127.0.0.1:6379。拒绝连接

2 个答案: