Docker是一个开源的引擎，可以轻松的为任何应用创建一个轻量级的、可移植的、自给自足的容器。开发者在笔记本上编译测试通过的容器可以批量地在生产环境中部署，包括VMs（虚拟机）、bare metal、OpenStack 集群和其他的基础应用平台。
源码
- github https://github.com/liangxiaobo/spring-boot-docker-example
- coding https://dev.tencent.com/u/liangxiaobo/p/docker-example/git
docker 环境准备
https://docs.docker.com/installation/#installation
打包方式一
简单的创建一个Dockerfile，放在项目根目录
FROM openjdk:8-jdk-alpine
VOLUME /tmp
COPY target/*.jar app.jar
ENTRYPOINT ["java","-jar","/app.jar"]
执行mvn命令
mvn install 或 mvn package
# 打包docker image
docker build -t myorg/myapp .
打包方式二
这种方式其实和上面的方式一样都是把target目录下生成的jar打包进镜像，不过需要插件帮助完成
<properties>
<docker.image.prefix>springio</docker.image.prefix>
<dockerfile.plugin.verion>1.4.9</dockerfile.plugin.verion>
</properties>
<build>
<plugins>
<!-- tag::plugin [] -->
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<!--end::plugin [] -->
<!-- tag::dockerfile [] -->
<plugin>
<groupId>com.spotify</groupId>
<artifactId>dockerfile-maven-plugin</artifactId>
<version>${dockerfile.plugin.verion}</version>
<configuration>
<repository>${docker.image.prefix}/${project.artifactId}</repository>
<!--<tag>${project.version}</tag>-->
<tag>latest</tag>
<buildArgs>
<JAR_FILE>target/${project.build.finalName}.jar</JAR_FILE>
</buildArgs>
</configuration>
</plugin>
<!-- end::dockerfile [] -->
</plugins>
</build>
Dockerfile
FROM openjdk:8-jdk-alpine
VOLUME /tmp
ARG JAR_FILE
COPY ${JAR_FILE} app.jar
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]
dockerfile插件： 说明
-
repository
指的是你的镜像仓库地址，如果你是私有库一般是ip:端口/imageName:tag,如果是公共库如docker hub 这用户名/imageName:tag，假如只是本地测试不用docker push，这里可以随便写符合规则就行 -
tag
设置镜像的tag属性，不设置的话默认就是最新 latest -
buildArgs
指的就是Dockerfile中的ARG 参数，这里JAR_FILE参数指的就是Dockerfile中的JAR_FILE
具体的ARG参数可以看这里
运行打包测试
进入项目目录
cd docker-example-copy-jar
mvn install dockerfile:build
打包成功后可以查看本地镜像 docker images
LiangdeMacBook-Pro:docker-example-copy-jar liangbo$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
springio/docker-example-copy-jar latest d6b3d432c014 42 seconds ago 122MB
openjdk 8-jdk-alpine a3562aa0b991 5 weeks ago 105MB
运行容器
docker run -ti -p 8080:8080 --entrypoint /bin/sh springio/docker-example-copy-jar
LiangdeMacBook-Pro:docker-example-copy-jar liangbo$ docker run -ti -p 8080:8080 --entrypoint /bin/sh springio/docker-example-copy-jar
/ # ls
app.jar bin dev etc home lib media mnt opt proc root run sbin srv sys tmp usr var
这种启动方式只适合测试，当你exit退出容器时，容器也停止运行
另一种方式
LiangdeMacBook-Pro:docker-example-copy-jar liangbo$ docker run -d --name app -p 8080:8080 springio/docker-example-copy-jar
819c4cd863857c90031ffded0681d90cc1b63c96c8b55d1e00f4cd9652dfc4be
LiangdeMacBook-Pro:docker-example-copy-jar liangbo$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
819c4cd86385 springio/docker-example-copy-jar "java -Djava.securit…" 2 seconds ago Up 1 second 0.0.0.0:8080->8080/tcp app
LiangdeMacBook-Pro:docker-example-copy-jar liangbo$ docker exec -it app ls
app.jar etc media proc sbin tmp
bin home mnt root srv usr
dev lib opt run sys var
访问 http://localhost:8080/hello
打包方式三
先将jar解压后进接打包进镜像，这样容器启动会更快一些
需要解压插件
<!-- tag::unpack [] -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>unpack</id>
<phase>package</phase>
<goals>
<goal>unpack</goal>
</goals>
<configuration>
<artifactItems>
<artifactItem>
<groupId>${project.groupId}</groupId>
<artifactId>${project.artifactId}</artifactId>
<version>${project.version}</version>
</artifactItem>
</artifactItems>
</configuration>
</execution>
</executions>
</plugin>
<!-- end::unpack [] -->
完成的pom
<properties>
<docker.image.prefix>springio</docker.image.prefix>
<dockerfile.plugin.verion>1.4.9</dockerfile.plugin.verion>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<!-- tag::plugin [] -->
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<!--end::plugin [] -->
<!-- tag::dockerfile [] -->
<plugin>
<groupId>com.spotify</groupId>
<artifactId>dockerfile-maven-plugin</artifactId>
<version>${dockerfile.plugin.verion}</version>
<configuration>
<repository>${docker.image.prefix}/${project.artifactId}</repository>
<!--<tag>${project.version}</tag>-->
<tag>latest</tag>
</configuration>
</plugin>
<!-- end::dockerfile [] -->
<!-- tag::unpack [] -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>unpack</id>
<phase>package</phase>
<goals>
<goal>unpack</goal>
</goals>
<configuration>
<artifactItems>
<artifactItem>
<groupId>${project.groupId}</groupId>
<artifactId>${project.artifactId}</artifactId>
<version>${project.version}</version>
</artifactItem>
</artifactItems>
</configuration>
</execution>
</executions>
</plugin>
<!-- end::unpack [] -->
</plugins>
</build>
Dockerfile
FROM openjdk:8-jdk-alpine
VOLUME /tmp
ARG DEPENDENCY=target/dependency
COPY ${DEPENDENCY}/BOOT-INF/lib /app/lib
COPY ${DEPENDENCY}/META-INF /app/META-INF
COPY ${DEPENDENCY}/BOOT-INF/classes /app
ENTRYPOINT ["java","-cp","app:app/lib/*","com.example.docker.dockerexamplecopysource.DockerExampleCopySourceApplication"]
当解压插件执行完成后，target目录下会有一个dependency目录
.
├── BOOT-INF
│ ├── classes
│ └── lib
├── META-INF
│ ├── MANIFEST.MF
│ └── maven
└── org
└── springframework
ENTRYPOINT最后一个参数是启动类
打包测试
和上面一样
cd docker-example-copy-source
mvn install dockerfile:build
打包成功后可以在本地查看镜像 docker images
LiangdeMacBook-Pro:docker-example-copy-source liangbo$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
springio/docker-example-copy-source latest 6dc944ee8069 About a minute ago 121MB
springio/docker-example-copy-jar latest d6b3d432c014 40 minutes ago 122MB
openjdk 8-jdk-alpine a3562aa0b991 5 weeks ago 105MB
运行容器
LiangdeMacBook-Pro:docker-example-copy-source liangbo$ docker run -d --name app2 -p 8081:8080 springio/docker-example-copy-source
faa9e4cf2399b61b315d7dc4d226b599a4b1aeaa58bc33c02f524a557fcfaca0
LiangdeMacBook-Pro:docker-example-copy-source liangbo$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
faa9e4cf2399 springio/docker-example-copy-source "java -cp app:app/li…" 2 seconds ago Up 1 second 0.0.0.0:8081->8080/tcp app2
可访问 http://localhost:8081/hello
最后查看一下容器内的文件
LiangdeMacBook-Pro:docker-example-copy-source liangbo$ docker exec -it app2 /bin/sh
/ # ls
app bin dev etc home lib media mnt opt proc root run sbin srv sys tmp usr var
/ # ls app
META-INF application.properties com lib
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