.NET Core+MySql+Nginx 容器化部署

.NET Core容器化@Docker
.NET Core容器化之多容器应用部署@Docker-Compose
.NET Core+MySql+Nginx 容器化部署
GitHub-Demo：Docker.NetCore.MySql

1. 引言

上两节我们通过简单的demo学习了docker的基本操作。这一节我们来一个进阶学习，完成ASP.NET Core + MySql + Nginx的容器化部署。

本文是基于CentOS 7.4环境进行演示，示例项目可以访问Docker.NetCore.MySql进行下载。

2. Hello MySQL

同样我们还是以循序渐进的方式来展开。首先来基于Docker来试玩一下MySQL。

2.1. 创建MySql实例

//拉取mysql镜像
 docker pull mysql
$ docker images$
REPOSITORY                           TAG                 IMAGE ID            CREATED             SIZE
docker.io/mysql                      latest              7d83a47ab2d2        13 days ago         408.2 MB
//创建一个mysql实例
$ docker run --name hello.mysql -e MYSQL_ROOT_PASSWORD=123456 -d mysql
$ docker ps 
CONTAINER ID        IMAGE      COMMAND                  CREATED             STATUS              PORTS          NAMES
e21bbd84e0b5        mysql      "docker-entrypoint.sh"   3 minutes ago       Up 3 minutes        3306/tcp        hello.mysql

下面我们直接在容器中连接到我们刚刚创建的mysql数据库：

$ docker exec -it hello.mysql 
> mysql -uroot -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or g.
Your MySQL connection id is 8
Server version: 5.7.20 MySQL Community Server (GPL)

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

2.2. 挂载数据卷

上面创建的mysql实例其数据都在容器内部存储，这样就暴露了一个问题，如果容器销毁，那么对应的数据库数据就会丢失。那如何持久化存储容器内数据呢？我们可以通过挂载数据卷的方式来解决这一问题。

//创建数据卷
$ docker volume create --name hello.db
hello.db
//查看数据卷信息
$ docker volume inspect hello.db
[
    {
        "Name": "hello.db",
        "Driver": "local",
        "Mountpoint": "/var/lib/docker/volumes/hello.db/_data",
        "Labels": {},
        "Scope": "local"
    }
]
// 挂载数据卷启动MySql实例
$ docker run --name hello.mysql 
> -v hello.db:/var/lib/mysql 
> -e MYSQL_ROOT_PASSWORD=123456 -d mysql

上面是使用使用了docker volume create命令创建了一个数据卷，当然我们也可以自行挂载某个目录作为数据卷。

3. 准备.NET Core+EFCore+MySql项目

为了演示方便，我准备了一个ASP.NET Core+EFCore+MySql的示例项目。其结构如下所示：

是基于.NET Core Mvc模板项目，其中定义了一个Product实体，并通过ProductsController暴露WebApi接口。核心代码如下：

Product实体类：

public class Product
{
    public int ProductId { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }
    public int StockQty { get; set; }
}

DbContext类：

public class MySqlDbContext : DbContext
{
    public MySqlDbContext (DbContextOptions<MySqlDbContext> options)
        : base(options)
    {
    }

    public DbSet<Product> Products { get; set; }
}

数据库初始化类：

public class DbInitializer
{
    public static void Initialize(MySqlDbContext context)
    {
        context.Database.EnsureCreated();

        if (context.Products.Any())
        {
            return;
        }

        var products = new Product[]
        {
            new Product{Name="iphone 6",Price=5000,StockQty=10 },
            new Product{Name="iphone 7",Price=6000,StockQty=10 },
            new Product{Name="iphone 7 plus",Price=7000,StockQty=10 },
            new Product{Name="iphone x",Price=8000,StockQty=10 }
        };

        context.Products.AddRange(products);

        context.SaveChanges();
    }
}

该数据库初始化类会在项目启动时运行。详细代码可参考Docker.NetCore.MySql。

4. 基于示例项目进行实操演练

4.1 安装Git并Clone示例项目

$ yum install git
$ git --version
git version 1.8.3.1
$ cd ~/demo
$ git clone https://github.com/yanshengjie/Docker.NetCore.MySql.git
Cloning into 'Docker.NetCore.MySql'...
remote: Counting objects: 155, done.
remote: Compressing objects: 100% (125/125), done.
remote: Total 155 (delta 42), reused 123 (delta 25), pack-reused 0
Receiving objects: 100% (155/155), 534.30 KiB | 333.00 KiB/s, done.
Resolving deltas: 100% (42/42), done.

4.2. 构建镜像

细心的你会发现，项目中已经定义了Dockerfile，所以我们可以直接使用docker build构建镜像。

# cd Docker.NetCore.MySql
[root@iZ288a3qazlZ Docker.NetCore.MySql]# ls
appsettings.Development.json  docker-compose.yml           Program.cs             Views
appsettings.json              Dockerfile                   proxy.conf             wwwroot
bundleconfig.json             Docker.NetCore.MySql.csproj  README.md
Controllers                   LICENSE                      ScaffoldingReadMe.txt
Data                          Models                       Startup.cs
//构建镜像
# docker build -t docker.netcore.mysql .
Sending build context to Docker daemon 3.045 MB
Step 1 : FROM microsoft/dotnet:latest
 ---> 7d4dc5c258eb
Step 2 : WORKDIR /app
 ---> Using cache
 ---> 98d48a4e278c
Step 3 : COPY . /app
 ---> 6b1bf8bb5261
Removing intermediate container b86460477977
Step 4 : RUN dotnet restore
 ---> Running in 4e0a46f762bb
  Restoring packages for /app/Docker.NetCore.MySql.csproj...
  Installing Microsoft.CodeAnalysis.Razor 2.0.0.
  .....
  Restore completed in 216.83 ms for /app/Docker.NetCore.MySql.csproj.
 ---> 4df70c77916e
Removing intermediate container 4e0a46f762bb
Step 5 : EXPOSE 5000
 ---> Running in 11b421b3bd3e
 ---> 3506253060fe
Removing intermediate container 11b421b3bd3e
Step 6 : ENV ASPNETCORE_URLS http://*:5000
 ---> Running in 201aabbab72c
 ---> 7f29963a8d96
Removing intermediate container 201aabbab72c
Step 7 : ENTRYPOINT dotnet run
 ---> Running in c79f73cba162
 ---> 9d1fb6ee46cb
Removing intermediate container c79f73cba162
Successfully built 9d1fb6ee46cb
[root@iZ288a3qazlZ Docker.NetCore.MySql]# docker images docker.netcore.mysql
REPOSITORY             TAG                 IMAGE ID            CREATED             SIZE
docker.netcore.mysql   latest              9d1fb6ee46cb        13 seconds ago      1.756 GB

4.3. 启动镜像并连接到指定数据库

docker提供了--link参数用于在容器之间建立连接。下面我们实例化创建的镜像docker.netcore.mysql并命名容器名为hello.netcore.mysql，并使用--link参数与我们文章开头建立的hello.mysql容器建立连接。

# docker run --name hello.netcore.mysql --link hello.mysql:db -d -p 5000:5000 
docker.netcore.mysql

这里需要特别注意一下--link=hello.mysql:db，这个参数就是告诉Docker容器需要使用hello.mysql容器，并将其别名命名为db，这样在hello.netcore.mysql这个容器中就可以使用db来作为提供mysql数据库服务的服务器。这也就是为什么我们.NET Core项目中连接字符串设置为server=db;的原因。
"ConnectionStrings": { "MySql": "server=db;database=MySqlDbContext;uid=root;pwd=123456;" }

//查看运行中容器列表
# docker ps 
CONTAINER ID        IMAGE                  COMMAND                  CREATED             STATUS              PORTS                    NAMES
5cbfd27ebe2a        docker.netcore.mysql   "dotnet run"             2 minutes ago       Up 2 minutes        0.0.0.0:5000->5000/tcp   hello.netcore.mysql
4dfa4159b669        mysql                  "docker-entrypoint.sh"   About an hour ago   Up About an hour    3306/tcp                 hello.mysql
//访问api/products
[root@iZ288a3qazlZ Docker.NetCore.MySql]# curl http://localhost:5000/api/products
[{"productId":1,"name":"iphone 6","price":5000.0000000000000000000000000,"stockQty":10},{"productId":2,"name":"iphone 7","price":6000.0000000000000000000000000,"stockQty":10},{"productId":3,"name":"iphone 7 plus","price":7000.0000000000000000000000000,"stockQty":10},{"productId":4,"name":"iphone x","price":8000.000000000000000000000000,"stockQty":10}]

从上图可知，我们完成了.NET Core与MySql的连接。

5. ASP.NET Core + MySql + Nginx

结合上一篇文章.NET Core容器化之多容器应用部署@Docker-Compose，我们来使用docker-compose完成asp.net core + mysql + nginx的多容器部署。

5.1. 定义 docker-compose.yml

version: '2'
services:
  db:
    container_name: hello.db
    environment:
      MYSQL_ROOT_PASSWORD: 123456
  volumes:
    - ./mysql:/var/lib/mysql

  web:
    container_name: hello.web
    build: .
    depends_on:
      - db
    links:
      - db
  
  reverse-proxy:
    container_name: hello.proxy
    image: nginx
    depends_on:
      - web
    ports:
      - "9090:8080"
    volumes:
      - ./proxy.conf:/etc/nginx/conf.d/default.conf

其中定义了三个服务：

1. db：使用mysql镜像，并挂载当前项目下的mysql文件夹来持久化存储。
2. web：基于当前项目构建的容器服务，依赖于db服务。
3. reverse-proxy：使用nginx定义反向代理服务，其中挂载了当前项目下的proxy.conf文件作为反向代理配置文件。其中proxy.conf的配置如下（注意proxy_pass指定的url为http://web:5000)：

server {
    listen 8080;

    location / {
        proxy_pass http://web:5000;
    }
}

5.2. 启动Compose

在启动Compose之前，建议清空上面创建的容器。也可以使用docker rm $(docker ps -qa)清除所有容器。

//启动compose
[root@iZ288a3qazlZ Docker.NetCore.MySql]# docker-compose up -d
Creating network "dockernetcoremysql_default" with the default driver
Building web
Step 1 : FROM microsoft/dotnet:latest
 ---> 7d4dc5c258eb
Step 2 : WORKDIR /app
 ---> Using cache
 ---> 98d48a4e278c
Step 3 : COPY . /app
 ---> d41b32323c0f
Removing intermediate container 1259f5fb82bc
Step 4 : RUN dotnet restore
 ---> Running in d482e355de77
  Restoring packages for /app/Docker.NetCore.MySql.csproj...
  Installing Microsoft.CodeAnalysis.Razor 2.0.0.
  .....
  Restore completed in 216.83 ms for /app/Docker.NetCore.MySql.csproj.
 ---> a0658008f161
Removing intermediate container d482e355de77
Step 5 : EXPOSE 5000
 ---> Running in dc6eeb29fd5e
 ---> a419314ece08
Removing intermediate container dc6eeb29fd5e
Step 6 : ENV ASPNETCORE_URLS http://*:5000
 ---> Running in c1d1474b14a0
 ---> 9cc13c549042
Removing intermediate container c1d1474b14a0
Step 7 : ENTRYPOINT dotnet run
 ---> Running in efdf0e857a84
 ---> 830ac11428cf
Removing intermediate container efdf0e857a84
Successfully built 830ac11428cf
Creating hello.db ... done
Creating hello.web ... done
Creating hello.proxy ... done
Creating hello.web ...
Creating hello.proxy ...
[root@iZ288a3qazlZ Docker.NetCore.MySql]# docker ps
CONTAINER ID        IMAGE                    COMMAND                  CREATED             STATUS              PORTS                            NAMES
6253bf85682e        nginx                    "nginx -g 'daemon off"   33 seconds ago      Up 28 seconds       80/tcp, 0.0.0.0:9090->8080/tcp   hello.proxy
ea553a9e22f2        dockernetcoremysql_web   "dotnet run"             37 seconds ago      Up 32 seconds       5000/tcp                         hello.web
a1f5aa981bfb        mysql                    "docker-entrypoint.sh"   38 seconds ago      Up 36 seconds       3306/tcp                         hello.db
[root@iZ288a3qazlZ Docker.NetCore.MySql]# docker-compose ps
   Name                 Command             State               Ports
----------------------------------------------------------------------------------
hello.db      docker-entrypoint.sh mysqld   Up      3306/tcp
hello.proxy   nginx -g daemon off;          Up      80/tcp, 0.0.0.0:9090->8080/tcp
hello.web     dotnet run                    Up      5000/tcp
[root@iZ288a3qazlZ Docker.NetCore.MySql]# curl http://localhost:9090/api/products
[{"productId":1,"name":"iphone 6","price":5000.0000000000000000000000000,"stockQty":10},{"productId":2,"name":"iphone 7","price":6000.0000000000000000000000000,"stockQty":10},{"productId":3,"name":"iphone 7 plus","price":7000.0000000000000000000000000,"stockQty":10},{"productId":4,"name":"iphone x","price":8000.000000000000000000000000,"stockQty":10}]

上面的运行结果显示，我们已经成功完成了ASP.NET Core+MySql+Nginx的多容器应用部署。通过浏览器访问http:<ipaddress>:9090/api/products即可访问我们暴露的api。

5.3. 数据库验证

我们来验证一下数据库是否成功创建：

[root@iZ288a3qazlZ Docker.NetCore.MySql]# ls mysql
auto.cnf         client-key.pem         ib_logfile0  performance_schema  server-key.pem
ca-key.pem       MySqlDbContext  ib_logfile1  private_key.pem     sys
ca.pem           ib_buffer_pool         ibtmp1       public_key.pem
client-cert.pem  ibdata1                mysql        server-cert.pem
[root@iZ288a3qazlZ Docker.NetCore.MySql]# docker exec -it hello.db mysql -uroot -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or g.
Your MySQL connection id is 8
Server version: 5.7.20 MySQL Community Server (GPL)

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
mysql> show databases;
+-----------------------+
| Database              |
+-----------------------+
| information_schema    |
| MySqlDbContext  |
| mysql                 |
| performance_schema    |
| sys                   |
+-----------------------+
5 rows in set (0.00 sec)

mysql> use MySqlDbContext;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> show tables;
+---------------------------------+
| Tables_in_MySqlDbContext |
+---------------------------------+
| Products                        |
+---------------------------------+
1 row in set (0.00 sec)

mysql> select * from Products;
+-----------+---------------+-------------------------------------+----------+
| ProductId | Name          | Price                               | StockQty |
+-----------+---------------+-------------------------------------+----------+
|         1 | iphone 6      | 5000.000000000000000000000000000000 |       10 |
|         2 | iphone 7      | 6000.000000000000000000000000000000 |       10 |
|         3 | iphone 7 plus | 7000.000000000000000000000000000000 |       10 |
|         4 | iphone x      | 8000.000000000000000000000000000000 |       10 |
+-----------+---------------+-------------------------------------+----------+
4 rows in set (0.00 sec)

从上面的运行结果可知，我们成功将项目文件夹下的mysql文件夹挂载到容器内部进行数据持久化。

6. 最后

本文通过先介绍如何基于Docker实例化MySQL容器，再介绍如何通过挂载数据卷来持久化MySQL数据，以及如何使用--Link参数进行容器之间的连接，完成了.NET Core连接MySQL数据库。
最后，使用Docker-Compose综合ASP.NET Core+MySQL+Nginx完成了容器化部署。

下一节我们来介绍下如何使用Docker-Swarm进行集群部署。

7. 参考资料

mysql -Docker Documentation
Hello Docker
.NET Core容器化@Docker
.NET Core容器化之多容器应用部署@Docker-Compose