使用docker-compose部署nginx+gunicorn+mariadb的django应用

1. docker-compose 项目的组织目录
2. 构建 mysql 容器
3. 构建 django-blog 容器
4. 构建 nginx 容器
5. docker-compose.yaml 文件
6. docker-compose up 启动服务组

我们来使用 docker-compose 并基于 gunicorn + mariadb + nginx 部署一个简单的 django 博客应用；

1. docker-compose 项目的组织目录

.
├── django-blog
│   ├── blogproject
│   │   ├── __init__.py
│   │   ├── settings.py
│   │   ├── urls.py
│   │   └── wsgi.py
│   ├── Dockerfile
│   ├── manage.py
│   ├── requirements.txt
│   └── static
├── docker-compose.yaml
├── mysql
│   ├── conf
│   │   └── django-blog.cnf
│   └── data
└── nginx
    ├── conf
    │   └── mysite.template
    ├── log
    └── ssl

2. 构建 mysql 容器

mysql/
├── conf
│   └── django-blog.cnf
└── data

配置数据库使用utf8mb4编码：

# mysql/conf/django-blog.cnf[client]
default-character-set = utf8mb4[mysql]
default-character-set = utf8mb4[mysqld]
character-set-client-handshake = FALSE
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci
init_connect='SET NAMES utf8mb4'

docker-compose.yaml 中 mysql service 的配置：

db:
    image: mariadb:10.4
    container_name: django-blog-db
    restart: always
    environment:
        MYSQL_ROOT_PASSWORD: <root 用户的密码>
        MYSQL_DATABASE: <容器启动时，自动创建的数据库名>
        MYSQL_USER: <容器启动时，自动创建的数据库用户，其对上述数据库拥有全部的权限>
        MYSQL_PASSWORD: <上述数据库用户的密码>
    volumes:
        - ./mysql/conf:/etc/mysql/conf.d  # 挂载自定义配置目录，即上述的 mysql/conf/django-blog.cnf 中的配置
        - ./mysql/data:/var/lib/mysql  # 挂载数据目录
        - ./mysql/log:/var/log  # 挂载日志目录

为什么不用 mysql，而是使用 mariadb ？

mysql:latest 默认的认证方式变为caching_sha2_password，直接使用会报错：Authentication plugin 'caching_sha2_password' cannot be loaded；

使用 mariadb:latest 或者使用 mysql:5.7 是没有问题的；

关于这个问题的讨论可以参考如下链接，里面提到一些规避的方法：
- caching_sha2_password介绍：
  - https://mysqlserverteam.com/mysql-8-0-4-new-default-authentication-plugin-caching_sha2_password/
- github 两个相关 issue 的讨论：
  - https://github.com/passbolt/passbolt_docker/issues/103
  - https://github.com/docker-library/mysql/issues/419

3. 构建 django-blog 容器

django-blog/
├── blogproject
│   ├── __init__.py
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
├── Dockerfile
├── manage.py
├── requirements.txt  # 包依赖
└── static  # python manage.py collectstatic 命令收集到的静态文件的目录

编写 Dockerfile：

FROM python:3.7-alpine  # 使用 alpine 版本，精简 image 体积；
RUN echo "https://mirrors.ustc.edu.cn/alpine/latest-stable/main" > /etc/apk/repositories \
    && apk update \
    # alpine 中 mariadb 代替了 mysql: <https://alpinelinux.org/posts/Alpine-3.2.0-released.html>
    && apk add mariadb-dev build-base
RUN mkdir /code
WORKDIR /code
COPY requirements.txt ./
RUN pip install --no-cache-dir -r requirements.txt

其中， requirements.txt 内容为：

-i https://mirrors.aliyun.com/pypi/simple
Django==2.2.5
django-haystack==2.8.1
gunicorn==19.9.0
jieba==0.39
Markdown==3.1.1
mysqlclient==1.4.4
Whoosh==2.7.4

docker-compose.yaml 中 web service 的配置：

web:
    build: django-blog/
    image: django-blog:2.2.5  # 构建后，image 的名字，2.2.5是目前使用的 django 版本
    container_name: django-blog-web
    restart: always
    depends_on:
        - db
    volumes:
         - ./django-blog:/code  # 挂载项目代码
         # - /code/static   # 可以选择不挂载项目代码中的 static 文件夹；https://stackoverflow.com/questions/29181032/add-a-volume-to-docker-but-exclude-a-sub-folder#
    command: /bin/bash -c "python manage.py makemigrations && python manage.py migrate && gunicorn blogproject.wsgi -w 3 -k gthread -b 0.0.0.0:8000"
    ports:
        - "8000:8000"
    environment:  # settings.py 中可以使用到的环境变量
        DB_NAME: <mysql 容器中配置的数据库>
        DB_USER: <mysql 容器中配置的数据库用户>
        DB_PASS: <mysql 容器中配置的数据库用户的密码>
        DB_PORT: 3306
        DJANGO_SECRET_KEY: "<django 密钥>"

修改 django-blog/blogproject/settings.py 文件相关项：

import os_env = os.environ# 使用上述定义的环境变量代替具体值
DATABASES = {
    # 'default': {
    #     'ENGINE': 'django.db.backends.sqlite3',
    #     'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
    # }
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': _env['DB_NAME'],
        'USER': _env['DB_USER'],
        'PASSWORD': _env['DB_PASS'],
        'HOST': 'db',  # docker-compose.yaml 中数据库的服务名
        'PORT': _env['DB_PORT'],  # 默认的服务端口号
        'OPTIONS': {
            # 存储引擎启用严格模式，非法数据值被拒绝
            'init_command': "SET sql_mode='STRICT_TRANS_TABLES'",
            'charset': 'utf8mb4',
        },
    }
}# 安全考虑，不要直接显示密钥，定义在容器的环境变量中
SECRET_KEY = os.environ['DJANGO_SECRET_KEY']# 生产环境不要将其置为 True
DEBUG = False

4. 构建 nginx 容器

nginx/
├── conf
│   └── mysite.template  # 用户配置
├── log
└── ssl  # 存放证书

docker-compose.yaml 中 nginx service 的配置：

nginx:
    image: nginx:stable  # 使用稳定版
    container_name: django-blog-nginx
    restart: always
    depends_on:
        - web
    ports:
        - 80:80
        - 443:443
    environment:  # 定义环境变量
        NGINX_HOST: luizyao.com
        NGINX_PORT: 80
        NGINX_SSL_PORT: 443
        WEB_PORT: 8000
    volumes:
        # 用户配置目录
        - ./nginx/conf/mysite.template:/etc/nginx/conf.d/mysite.template
        # ssl 证书目录
        - ./nginx/ssl:/etc/nginx/ssl
        # 静态文件，即 python manage.py collectstatic 命令收集到的静态文件的目录
        - ./django-blog/static:/data/apps/django-blog/static
        # 日志
        - ./nginx/log/:/var/log/nginx/
    command: /bin/bash -c "envsubst '$$NGINX_HOST $$NGINX_PORT $$NGINX_SSL_PORT $$WEB_PORT' < /etc/nginx/conf.d/mysite.template > /etc/nginx/conf.d/default.conf && exec nginx -g 'daemon off;'"  # 只有这几个变量需要转义：'$$NGINX_HOST $$NGINX_PORT $$NGINX_SSL_PORT $$WEB_PORT'，否则会报错

编写 mysite.template 文件：

upstream django-blog {
        server web:${WEB_PORT};
}server {
        charset utf-8;
        listen ${NGINX_PORT};
        server_name ${NGINX_HOST};        rewrite ^(.*)$ https://${server_name}$1 permanent;
}server {
        listen ${NGINX_SSL_PORT} ssl http2 default_server;
        server_name ${NGINX_HOST};        ssl_certificate /etc/nginx/ssl/1_www.luizyao.com_bundle.crt;
        ssl_certificate_key /etc/nginx/ssl/2_www.luizyao.com.key;
        ssl_session_timeout 5m;
        ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
        ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:HIGH:!aNULL:!MD5:!RC4:!DHE;
        ssl_prefer_server_ciphers on;        location /static {
                alias /data/apps/django-blog/static;
        }        location / {
                proxy_pass http://django-blog;
                proxy_redirect    off;
                proxy_set_header  Host $http_host;
                proxy_set_header  X-Real-IP $remote_addr;
        }        error_page 404 /404.html;
        location = /40x.html {}        error_page 500 502 503 504 /50x.html;
        location = /50x.html {}
}

5. docker-compose.yaml 文件

version: '3.7'  # docker 版本：18.06.0+services:
    db:
        image: mariadb:10.4
        container_name: django-blog-db
        restart: always
        environment:
            MYSQL_ROOT_PASSWORD: <root 用户的密码>
            MYSQL_DATABASE: <容器启动时，自动创建的数据库名>
            MYSQL_USER: <容器启动时，自动创建的数据库用户，其对上述数据库拥有全部的权限>
            MYSQL_PASSWORD: <上述数据库用户的密码>
        volumes:
            - ./mysql/conf:/etc/mysql/conf.d  # 挂载自定义配置
            - ./mysql/data:/var/lib/mysql  # 挂载数据存储目录
            - ./mysql/log:/var/log  # 挂载日志存储目录    web:
        build: django-blog/
        image: django-blog:2.2.5  # 构建后，image 的名字，2.2.5是目前使用的 django 版本
        container_name: django-blog-web
        restart: always
        depends_on:
            - db
        volumes:
             - ./django-blog:/code  # 挂载项目代码
             # - /code/static   # 可以选择不挂载项目代码中的 static 文件夹；https://stackoverflow.com/questions/29181032/add-a-volume-to-docker-but-exclude-a-sub-folder#
        command: /bin/bash -c "python manage.py makemigrations && python manage.py migrate && gunicorn blogproject.wsgi -w 3 -k gthread -b 0.0.0.0:8000"
        ports:
            - "8000:8000"
        environment:  # settings.py 中可以使用到的环境变量
            DB_NAME: <mysql 容器中配置的数据库>
            DB_USER: <mysql 容器中配置的数据库用户>
            DB_PASS: <mysql 容器中配置的数据库用户的密码>
            DB_PORT: 3306
            DJANGO_SECRET_KEY: "<django 密钥>"    nginx:
        image: nginx:stable  # 使用稳定版
        container_name: django-blog-nginx
        restart: always
        depends_on:
            - web
        ports:
            - 80:80
            - 443:443
        environment:  # 定义环境变量
            NGINX_HOST: luizyao.com
            NGINX_PORT: 80
            NGINX_SSL_PORT: 443
            WEB_PORT: 8000
        volumes:
            # 用户配置目录
            - ./nginx/conf/mysite.template:/etc/nginx/conf.d/mysite.template
            # ssl 证书目录
            - ./nginx/ssl:/etc/nginx/ssl
            # 静态文件，即 python manage.py collectstatic 命令收集到的静态文件的目录
            - ./django-blog/static:/data/apps/django-blog/static
            # 日志
            - ./nginx/log/:/var/log/nginx/
        command: /bin/bash -c "envsubst '$$NGINX_HOST $$NGINX_PORT $$NGINX_SSL_PORT $$WEB_PORT' < /etc/nginx/conf.d/mysite.template > /etc/nginx/conf.d/default.conf && exec nginx -g 'daemon off;'"  # 只有这几个变量需要转义：'$$NGINX_HOST $$NGINX_PORT $$NGINX_SSL_PORT $$WEB_PORT'，否则会报错

6. docker-compose up 启动服务组

[luizyao@centos_7_6_1810 blog]$ docker-compose up
Creating network "blog_default" with the default driver
Creating django-blog-db ... done
Creating django-blog-web ... done
Creating django-blog-nginx ... done
Attaching to django-blog-db, django-blog-web, django-blog-nginx
django-blog-db | 2019-09-24  8:45:41 0 [Note] mysqld (mysqld 10.4.8-MariaDB-1:10.4.8+maria~bionic) starting as process 1 ...
django-blog-db | 2019-09-24  8:45:41 0 [Note] InnoDB: Using Linux native AIO
django-blog-db | 2019-09-24  8:45:41 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins django-blog-db | 2019-09-24  8:45:41 0 [Note] InnoDB: Uses event mutexes
django-blog-db | 2019-09-24  8:45:41 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
django-blog-db | 2019-09-24  8:45:41 0 [Note] InnoDB: Number of pools: 1
django-blog-db | 2019-09-24  8:45:41 0 [Note] InnoDB: Using SSE2 crc32 instructions
django-blog-db | 2019-09-24  8:45:41 0 [Note] mysqld: O_TMPFILE is not supported on /tmp (disabling future attempts)
django-blog-db | 2019-09-24  8:45:41 0 [Note] InnoDB: Initializing buffer pool, total size = 256M, instances = 1, chunk size = 128M
django-blog-db | 2019-09-24  8:45:41 0 [Note] InnoDB: Completed initialization of buffer pool
django-blog-db | 2019-09-24  8:45:41 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
django-blog-db | 2019-09-24  8:45:42 0 [Note] InnoDB: 128 out of 128 rollback segments are active. django-blog-db | 2019-09-24  8:45:42 0 [Note] InnoDB: Creating shared tablespace for temporary tables
django-blog-db | 2019-09-24  8:45:42 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
django-blog-db | 2019-09-24  8:45:42 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
django-blog-db | 2019-09-24  8:45:42 0 [Note] InnoDB: Waiting for purge to start
django-blog-db | 2019-09-24  8:45:42 0 [Note] InnoDB: 10.4.8 started; log sequence number 21042225; transaction id 15378
django-blog-db | 2019-09-24  8:45:42 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
django-blog-db | 2019-09-24  8:45:42 0 [Note] Plugin 'FEEDBACK' is disabled.
django-blog-db | 2019-09-24  8:45:42 0 [Note] Server socket created on IP: '::'.
django-blog-db | 2019-09-24  8:45:42 0 [Note] Reading of all Master_info entries succeeded
django-blog-db | 2019-09-24  8:45:42 0 [Note] Added new Master_info '' to hash table
django-blog-db | 2019-09-24  8:45:42 0 [Note] mysqld: ready for connections.
django-blog-db | Version: '10.4.8-MariaDB-1:10.4.8+maria~bionic'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  mariadb.org binary distribution
django-blog-web | No changes detected
django-blog-db | 2019-09-24  8:45:43 0 [Note] InnoDB: Buffer pool(s) load completed at 190924  8:45:43
django-blog-web | Operations to perform:
django-blog-web |   Apply all migrations: admin, auth, blog, comment, contenttypes, sessions
django-blog-web | Running migrations:
django-blog-web |   No migrations to apply.
django-blog-web | [2019-09-24 08:45:44 +0000] [1] [INFO] Starting gunicorn 19.9.0
django-blog-web | [2019-09-24 08:45:44 +0000] [1] [INFO] Listening at: http://0.0.0.0:8000 (1)
django-blog-web | [2019-09-24 08:45:44 +0000] [1] [INFO] Using worker: gthread
django-blog-web | [2019-09-24 08:45:44 +0000] [10] [INFO] Booting worker with pid: 10
django-blog-web | [2019-09-24 08:45:44 +0000] [11] [INFO] Booting worker with pid: 11
django-blog-web | [2019-09-24 08:45:44 +0000] [12] [INFO] Booting worker with pid: 12