django无法在docker-compose中连接mysql [英] django cannot connect mysql in docker-compose

问题描述

我对Docker非常陌生，现在我想通过docker-compose在docker中使用mariadb运行django，但我总是会收到此错误:

I'm very new for docker, now I am trying to run django with mariadb in docker through docker-compose, but I always get this error:

我使用 Docker版本17.09.1-ce，内部版本19e2cf6 ， docker-compose版本1.18.0，内部版本8dd22a9

django.db.utils.OperationalError:(2003，'无法连接到MySQL\'mariadb55 \'上的服务器(111连接被拒绝")')

django.db.utils.OperationalError: (2003, 'Can\'t connect to MySQL server on \'mariadb55\' (111 "Connection refused")')

在本地或远程运行 docker-compose up db 后，我可以正确连接数据库，甚至可以正确运行 python manage.py runserver 0.0.0.0:6001 通过设置 settings.py 文件的参数，在 anaconda虚拟环境中连接docker中的 db 服务:

I can connect db correctly after run docker-compose up db in local or remote, and I even can run python manage.py runserver 0.0.0.0:6001 correctly in anaconda virtual environment to connect db service in docker by setting parameters of settings.py file like below:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'test',
        'USER': 'belter',
        # 'HOST': 'mariadb55',
        'HOST': '127.0.0.1',
        'PORT': '3302',
        'PASSWORD': 'belter_2017',
        'default-character-set': 'utf8',
        'OPTIONS': {
            'sql_mode': 'traditional',
        }
    }
}

这是我的 docker-compose.yml 文件

version: '3'

services:
  db:
    image: mariadb:5.5
    restart: always
    environment:
      - MYSQL_HOST=localhost
      - MYSQL_PORT=3306
      - MYSQL_ROOT_HOST=%
      - MYSQL_DATABASE=test
      - MYSQL_USER=belter
      - MYSQL_PASSWORD=belter_2017
      - MYSQL_ROOT_PASSWORD=123456_abc
    volumes:
      - /home/belter/mdbdata/mdb55:/var/lib/mysql
    ports:
      - "3302:3306"
  web:
    image: onlybelter/django_py35
    command: python3 manage.py runserver 0.0.0.0:6001
    volumes:
      - /mnt/data/www/mysite:/djcode
    ports:
      - "6001:6001"
    depends_on:
      - db
    links:
      - db:mariadb55

我几乎尝试了所有可以找到的东西，但仍然无法弄清楚，任何帮助都将很不错！

I almost tried everything I can find, but still cannot figure it out, any help would be nice!

我尝试过的事情:

Docker编写mysql连接失败

使用docker-compose链接django和mysql容器

通过docker-compose Django与Postgres的连接

推荐答案

最后，我知道了！关键是，正如@SangminKi​​m所说，我需要在 settings.py 中使用 3306 而不是 3302 ，并使用 db作为 HOST 而不是 127.0.0.1 .

Finally, I figured it out! The key point is, just as @SangminKim said, I need to use 3306 not 3302 in settings.py, and use db as HOST not 127.0.0.1.

所以这是我的 docker-compose.yml 文件:

version: '3'

services:
  db:
    image: mariadb:5.5
    restart: always
    environment:
      - MYSQL_HOST=localhost
      - MYSQL_PORT=3306  # cannot change this port to other number
      - MYSQL_ROOT_HOST=%
      - MYSQL_DATABASE=test
      - MYSQL_USER=belter
      - MYSQL_PASSWORD=belter_2017
      - MYSQL_ROOT_PASSWORD=123456_abc
    volumes:
      - /home/belter/mdbdata/mdb55:/var/lib/mysql
    ports:
      - "3302:3306"
  web:
    image: onlybelter/django_py35
    command: python3 manage.py runserver 0.0.0.0:6001
    volumes:
      - .:/djcode
    ports:
      - "6001:6001"
    depends_on:
      - db

所以现在我们可以通过 mysql -h 127.0.0.1 -P 3302 -u root -p 直接在shell中连接此 docker-mysql ，但是我们必须使用Django settings.py 文件中的 db 和 3306 :

So now we can connect this docker-mysql by mysql -h 127.0.0.1 -P 3302 -u root -p in shell directly, but we have to use db and 3306 in django settings.py file:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'test',
        'USER': 'belter',
        # 'HOST': 'mariadb55',
        'HOST': 'db',  #<---
        'PORT': '3306',   #<---
        'PASSWORD': 'belter_2017',
        'default-character-set': 'utf8',
        'OPTIONS': {
            'sql_mode': 'traditional',
        }
    }
}

我们仍然可以通过在 docker-compose.yml 文件中运行额外的命令来检查此端口是否打开:

And we can still check if this port is open, by running extra command in docker-compose.yml file:

...
  web:
    image: onlybelter/django_py35
    command: /bin/sh -c "python check_db.py --service-name mysql --ip db --port 3306"
    volumes:
      - .:/djcode
...

这是 check_db.py 文件:

# check_db.py 

import socket
import time
import argparse
""" Check if port is open, avoid docker-compose race condition """

parser = argparse.ArgumentParser(description='Check if port is open, avoid\
                                 docker-compose race condition')
parser.add_argument('--service-name', required=True)
parser.add_argument('--ip', required=True)
parser.add_argument('--port', required=True)

args = parser.parse_args()

# Get arguments
service_name = str(args.service_name)
port = int(args.port)
ip = str(args.ip)

# Infinite loop
while True:
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    result = sock.connect_ex((ip, port))
    if result == 0:
        print("{0} port is open! Bye!".format(service_name))
        break
    else:
        print("{0} port is not open! I'll check it soon!".format(service_name))
        time.sleep(3)

顺便说一下，这是我用于构建 django-py35 的 Dockerfile :

By the way, this is my Dockerfile for build django-py35:

FROM python:3.5-alpine
MAINTAINER Xin Xiong "[e-mail]"
ENV PYTHONUNBUFFERED 1
RUN set -e; \
        apk add --no-cache --virtual .build-deps \
                gcc \
                libc-dev \
                linux-headers \
                mariadb-dev \
                python3-dev \
                postgresql-dev \
                freetype-dev \
                libpng-dev \
                g++ \
        ;
RUN mkdir /djcode
WORKDIR /djcode
ENV REFRESHED_AT 2017-12-25
ADD requirements.txt /djcode/
RUN pip install --no-cache-dir -r /djcode/requirements.txt
RUN pip install uwsgi
ADD . /djcode/  # copy . to /djcode/
EXPOSE 6001

从此处查看更多详细信息: https://github.com/OnlyBelter/django-compose

See more details from here: https://github.com/OnlyBelter/django-compose

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