服务docker化 - James blog

运维采用k8s后，相关服务需要做到自动生成Docker images并上传到私服，私服采用的阿里云仓库并配合VPC网络

Java环境说明

jdk 1.8
spring-boot 2.0
maven
dockerfile-maven 1.3.6

Java image

项目采用Maven构建，使用dockerfile-maven-plugin来做docker images的构建与上传

插件引用

在pom.xml中添加插件引用

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-deploy-plugin</artifactId>
    <version>2.7</version>
    <configuration>
        <!-- 排除该工程不deploy 到远程服务器上 -->
        <skip>true</skip>
    </configuration>
</plugin>
<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <configuration>
        <mainClass>vc.thinker.cabbage.web.AdminServerMain</mainClass>
        <layout>JAR</layout>
        <executable>true</executable>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>repackage</goal>
            </goals>
        </execution>
    </executions>
</plugin>
<plugin>
    <groupId>com.spotify</groupId>
    <artifactId>dockerfile-maven-plugin</artifactId>
    <version>1.3.6</version>
    <executions>
        <execution>
            <id>default</id>
            <goals>
                <goal>build</goal>
                <goal>push</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <!-- 仓库地址 -->
        <repository>registry-vpc.cn-shenzhen.aliyuncs.com/xxx/${project.artifactId}</repository>
        <!-- docker images tag -->
        <tag>${project.version}</tag>
        <!-- 采用Maven Settings进行docker仓库授权 -->
        <useMavenSettingsForAuth>true</useMavenSettingsForAuth>
        <!-- dockerfile ARG,buildArgs可自定义多个配合dockerfile 的ARG指令使用 -->
        <buildArgs>
            <!-- jar地址 -->
            <JAR_FILE>target/${project.build.finalName}.jar</JAR_FILE>
            <!-- 配制文件地址 -->
            <PROPERTIES>target/classes/${project.build.finalName}/application.properties</PROPERTIES>
            <!-- 启动执行命令 -->
            <START>target/classes/${project.build.finalName}/k8s-start.sh</START>
        </buildArgs>
    </configuration>
</plugin>

dockerfile

在项目根目录下添加Dockerfile文件

#built java images,注意本例中没有处理时区问题
FROM openjdk:8-jre

ARG JAR_FILE
ARG PROPERTIES
ARG START

COPY ${JAR_FILE} /JAVA/app.jar

COPY ${PROPERTIES} /JAVA/application.properties

COPY ${START} /JAVA/k8s-start.sh

RUN chmod +x /JAVA/k8s-start.sh && \
    ln -s /JAVA/k8s-start.sh /usr/bin/k8s-start

#web 服务端口
EXPOSE 8080

#CMD ["k8s-start"]
ENTRYPOINT ["k8s-start"]

配制文件与执行命令

src/main/resources 下添加 k8s-start.sh 和 application.properties,这里说明一下k8s-start.sh

#!/bin/sh

#采用环境变量的方式修改配制文档，由于环境变量不能有".-"字符，约定".-"统一转换为下划线_
function change(){
        echo "準備修改配置項 $1"
        local j=`echo "$1"| sed 's/\./_/g'| sed 's/\-/_/g'`
        #echo $j
        local i=`eval echo '$'{"$j"}`
        echo "對應變量為 $j"
        [[ ! $i ]] && echo "$j 環境變量不存在，不進行替換！" && return 0
        sed -i "s/$1=.*/$1=$i/" /ROOT/application.properties && echo "替換變量 $i 成功 "
}


#修改配制文档，
change spring.datasource.url
change spring.datasource.username
change spring.datasource.password

cd /JAVA

if [[ "$1" == 'sh' || "$1" == 'bash' || "$1" == '/bin/sh' ]]; then
  exec "/bin/sh"
fi

#java-conf为jvm参数
echo "配置：java-conf=$java_conf"
if [ "${java_conf}" ]; then
  echo "运行java命令：java $java_conf -jar app.jar "
  exec su-exec java java $java_conf -jar app.jar
fi

echo "运行java命令：java "$@" -jar app.jar"

exec su-exec java java "$@" -jar app.jar

docker仓库权限

在maven settings.xml设置仓库地址与权限

<configuration>
  <repository>docker-repo.example.com:8080/organization/image</repository>
  <tag>latest</tag>
  <useMavenSettingsForAuth>true</useMavenSettingsForAuth>
</configuration>

权限

<servers>
  <server>
    <id>docker-repo.example.com:8080</id>
    <username>me</username>
    <password>mypassword</password>
  </server>
</servers>

使用说明

本例中直接执行 mvn deploy 就可以做到docker images的构建和上传

mvn deploy

本地运行

docker run --name my-server -p 8080:8080 \
-e spring_datasource_username="test"
-d images:tag \

-e spring_datasource_username=”test” 为修改application.properties中的spring.datasource.username配制

Dockerfile Maven的特性

默认，构建Dockerfile的过程包含在mvn package阶段；

默认，为Dockerfile打标签的过程包含在mvn package阶段；

默认，发布Dockerfile的过程包含在mvn deploy阶段；

也可以直接陆续执行：

mvn dockerfile:build

mvn dockerfile:tag

mvn dockerfile:push

如运行出现 “No plugin found for prefix ‘dockerfile’ in the current project and in the plugin groups [org.apache.maven.plugins”我们需要在settings.xml里把这个插件加入白名单

<settings>
    <pluginGroups>
        <pluginGroup>com.spotify</pluginGroup>
    </pluginGroups>
</settings>

跳过Dockerfile相关的构建、发布

如果要临时跳过所有的Dockerfile相关的所有3个goals，执行如下Maven命令：

mvn clean package -Ddockerfile.skip

如果只是想跳过某一个goal，执行如下Maven命令：

mvn clean package -Ddockerfile.build.skip

mvn clean package -Ddockerfile.tag.skip

mvn clean package -Ddockerfile.push.skip