容器化开发环境 - 数据库连接和迁移

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:

Setup Codebase

  • clone hello-dockerize repo
    1
    $ git clone https://github.com/aikin/hello-dockerize.git

Install MySQL On Docker Image

  • 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:

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    # === 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 <mysql-build@oss.oracle.com>" 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。

    1
    2
    3
    4
    MYSQL_USER=mysql
    MYSQL_PASSWORD=mysql
    MYSQL_DATABASE=hello_dockerize
    MYSQL_ROOT_PASSWORD=12345678
  • 修改docker-compose.yml

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    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

    1
    $ docker-compose run --service-ports web

Use Database Migrations Flyway

  • 新建文件db.mysql.gradle

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    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

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    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

    1
    2
    3
    4
    5
    6
    7
    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:

    1
    $ ./gradlew flywayClean flywayInit flywayMigrate

Check Migrate Result On Intellij IDEA

  • 安装 Intellij IDEA plugin Database Navigator,配置connections

    connections

  • 查看User表数据

    user table
    user data

  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。