容器化开发环境 - 数据库连接和迁移

在 容器化开发环境 中分享了如何容器化本地的开发环境。对于一个Web应用，数据库似乎是必不可少的东西。下面会通过例子来介绍一下如何Setup一个容器中的数据库。例子将会使用的技术栈：

• MySQL

• Flyway

• ...

Setup Codebase

• clone hello-dockerize repo

  $ git clone https://github.com/aikin/hello-dockerize.git

Install MySQL On Docker Image

• 在dockerize目录下新建文件docker-entrypoint.sh，用于控制MySQL数据库的启动。

• 修改Dockerfile，添加安装MySQL的配置：

  # === Install Mysql ===
  RUN groupadd -r mysql && useradd -r -g mysql mysql
  
  RUN mkdir /docker-entrypoint-initdb.d
  
  ENV MYSQL_MAJOR 5.7
  ENV MYSQL_VERSION 5.7.11-1ubuntu14.04
  
  # gpg: key 5072E1F5: public key "MySQL Release Engineering <[e-mail]>" imported
  RUN apt-key adv --keyserver ha.pool.sks-keyservers.net --recv-keys A4A9406876FCBD3C456770C88C718D3B5072E1F5
  
  RUN echo "deb http://repo.mysql.com/apt/ubuntu/ trusty mysql-${MYSQL_MAJOR}" > /etc/apt/sources.list.d/mysql.list
  
  # the "/var/lib/mysql" stuff here is because the mysql-server postinst doesn't have an explicit way to disable the mysql_install_db codepath besides having a database already "configured" (ie, stuff in /var/lib/mysql/mysql)
  # also, we set debconf keys to make APT a little quieter
  RUN { \
  echo mysql-community-server mysql-community-server/data-dir select ''; \
  echo mysql-community-server mysql-community-server/root-pass password ''; \
  echo mysql-community-server mysql-community-server/re-root-pass password ''; \
  echo mysql-community-server mysql-community-server/remove-test-db select false; \
  } | debconf-set-selections
  
  RUN apt-get update
  RUN apt-get install -y mysql-server="${MYSQL_VERSION}"
  RUN rm -rf /var/lib/apt/lists/*
  RUN rm -rf /var/lib/mysql && mkdir -p /var/lib/mysql
  
  # comment out a few problematic configuration values
  # don't reverse lookup hostnames, they are usually another container
  RUN sed -Ei 's/^(bind-address|log)/#&/' /etc/mysql/my.cnf \
  && echo 'skip-host-cache\nskip-name-resolve' | awk '{ print } $1 == "[mysqld]" && c == 0 { c = 1; system("cat") }' /etc/mysql/my.cnf > /tmp/my.cnf \
  && mv /tmp/my.cnf /etc/mysql/my.cnf
  
  VOLUME /var/lib/mysql
  
  COPY docker-entrypoint.sh /usr/local/bin/
  RUN chmod +x /usr/local/bin/docker-entrypoint.sh
  RUN ln -s usr/local/bin/docker-entrypoint.sh /entrypoint.sh # backwards compat
  ENTRYPOINT ["docker-entrypoint.sh"]
  
  EXPOSE 3306
  CMD ["mysqld"]

• 新建文件dev.env，用于配置数据库账号和密码。

  MYSQL_USER=mysql
  MYSQL_PASSWORD=mysql
  MYSQL_DATABASE=hello_dockerize
  MYSQL_ROOT_PASSWORD=12345678

• 修改docker-compose.yml

  web:
    build: ./dockerize
    env_file: ./dockerize/dev.env
    environment:
  - LANG=C.UTF-8
  - TERM=xterm
  - DEBUG=true
    ports:
  - "8080:8080"
  - "3306:3306"
  - "5005:5005"
    volumes:
  - .:/hello-dockerize
  - /var/lib/mysql:/var/lib/mysql

• 启动容器

  $ docker-compose run --service-ports web

Use Database Migrations Flyway

• 新建文件db.mysql.gradle

  flyway {
      driver = 'com.mysql.jdbc.Driver'
      url = "jdbc:mysql://dockerhost:3306/hello_dockerize"
      user = 'mysql'
      password = 'mysql'
      table = 'hello_dockerize_schema_version'
      initOnMigrate = true
      locations = ["filesystem:${projectDir}/src/main/resources/db/migration/mysql"]
      sqlMigrationPrefix = 'MySQL-'
  }
  
  dependencies {
      compile 'mysql:mysql-connector-java:5.1.34'
  }

• 修改build.gradle文件，添加

  buildscript {
      repositories {
          jcenter()
          maven { url "http://repo.spring.io/snapshot" }
          maven { url "http://repo.spring.io/milestone" }
      }
      dependencies {
          classpath("org.springframework.boot:spring-boot-gradle-plugin:1.3.5.RELEASE")
          classpath "org.flywaydb:flyway-gradle-plugin:3.0"
      }
  }
  apply plugin: 'flyway'
  apply from: "db.mysql.gradle"

• 新建目录 src/main/resources/db/migration/mysql，添加 migration sql 脚本MySQL-1_1__create_user.sql：

  CREATE TABLE User (
      ID          BIGINT PRIMARY KEY   AUTO_INCREMENT,
      FIRST_NAME  varchar(64) NOT NULL,
      LAST_NAME   varchar(64) NOT NULL
  ) ENGINE = InnoDB DEFAULT CHARSET = utf8;
  
  insert into User (FIRST_NAME, LAST_NAME) values ('Laijin', 'Lu');

• 执行 migrate 命令:

  $ ./gradlew flywayClean flywayInit flywayMigrate

Check Migrate Result On Intellij IDEA

• 安装 Intellij IDEA plugin Database Navigator，配置connections：

• 查看User表数据

　 结束了吗？并没有，如何将应用和数据库分离成两个独立的容器。

原文链接