将微服务运行在Docker上
我们需要把之前的微服务部署到docker上去，之前的微服务搭建可以翻看我博客的【Spring Cloud 基础设施搭建系列】
我对之前的一些配置进行了抽取，抽取了common的配置，并且放置到配置中心,还解决了Admin Server中无法获取Config Server的健康状态，解决方法是在Config Server的security配置中过滤掉"/actuator/health"端点。
可以参考我的gitee:
https://gitee.com/cckevincyh/spring-cloud-demo/tree/config-refactor/
这次我们主要讲一下如何使用Maven插件构建Docker镜像，如果对Docker不熟悉的可以先去看看Docker的基础使用。
使用Maven插件构建Docker镜像
Maven是一个强大的项目管理与构建工具。如果可以使用Maven构建Docker镜像，工作就能得到进一步的简化。
我们以cloud-eureka为例子，演示一下如何使用Maven插件构建Docker镜像
- 首先我们需要在parent pom文件中加入maven的插件。
我们这里使用的是spotify的docker插件。
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<version>0.4.13</version>
<configuration>
<forceTags>true</forceTags>
<imageName>spring-cloud-demo/${project.artifactId}:${project.version}</imageName>
<baseImage>java</baseImage>
<entryPoint>["java", "-jar", "/${project.build.finalName}.jar"]</entryPoint>
<resources>
<resource>
<targetPath>/</targetPath>
<directory>${project.build.directory}</directory>
<include>${project.build.finalName}.jar</include>
</resource>
</resources>
</configuration>
</plugin>
简要说明一下插件的配置：
- imageName：用于指定镜像名称，其中spring-cloud-demo是仓库名称，${project.artifactId}是镜像名称, ${project.version}是标签名称。
- baselmage：用于指定基础镜像，类似于Dockerfile中的FROM指令。
- entrypoint：类似于Dockerfile的ENTRYPOINT指令。
- resources.resource.directory：用于指定需要复制的根目录，${project.build.directory}
表示target目录。- resources.resource.include：用于指定需要复制的文件。${project.build.finalName}.jar指的是打包后的jar包文件。
${project.build.finalName},${project.build.directory}对应的值到底是什么呢？
我们可以右键我们的cloud-eureka项目，找到Maven-> Show Effective POM,然后搜索finalName就可以找到。
其实${project.build.finalName}默认值就是为${project.artifactId}-${project.version}
我们搜directory就可以找到${project.build.directory}。
其实${project.build.directory}是构建目录，默认为target目录
Maven内置变量说明：
${basedir}项目根目录${project.build.directory}构建目录，缺省为target${project.build.outputDirectory}构建过程输出目录，缺省为target/classes${project.build.finalName}产出物名称，缺省为${project.artifactId}-${project.version}${project.packaging}打包类型，缺省为jar${project.xxx}当前pom文件的任意节点的内容
参考：
Maven学习笔记（一）——自定义maven变量以及maven内置常量
What is the value of project.build.finalName?
- 执行以下命令，构建Docker镜像
mvn clean package docker:build
C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka>mvn clean package docker:build
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building cloud-eureka 1.0
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:3.1.0:clean (default-clean) @ cloud-eureka ---
[INFO] Deleting C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target
[INFO]
[INFO] --- maven-resources-plugin:3.1.0:resources (default-resources) @ cloud-eureka ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.8.0:compile (default-compile) @ cloud-eureka ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\classes
[INFO]
[INFO] --- maven-resources-plugin:3.1.0:testResources (default-testResources) @ cloud-eureka ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\src\test\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.8.0:testCompile (default-testCompile) @ cloud-eureka ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-surefire-plugin:2.22.1:test (default-test) @ cloud-eureka ---
[INFO] No tests to run.
[INFO]
[INFO] --- maven-jar-plugin:3.1.0:jar (default-jar) @ cloud-eureka ---
[INFO] Building jar: C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\cloud-eureka-1.0.jar
[INFO]
[INFO] --- spring-boot-maven-plugin:2.1.1.RELEASE:repackage (repackage) @ cloud-eureka ---
[INFO] Replacing main artifact with repackaged archive
[INFO]
[INFO] --- docker-maven-plugin:0.4.13:build (default-cli) @ cloud-eureka ---
[INFO] Copying C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\cloud-eureka-1.0.jar -> C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\docker\cloud-eu
reka-1.0.jar
[INFO] Building image cloud-demo/cloud-eureka:1.0
Step 1/3 : FROM java
Pulling from library/java
5040bd298390: Pulling fs layer
fce5728aad85: Pulling fs layer
76610ec20bf5: Pulling fs layer
60170fec2151: Pulling fs layer
e98f73de8f0d: Pulling fs layer
11f7af24ed9c: Pulling fs layer
49e2d6393f32: Pulling fs layer
bb9cdec9c7f3: Pulling fs layer
60170fec2151: Waiting
e98f73de8f0d: Waiting
11f7af24ed9c: Waiting
49e2d6393f32: Waiting
bb9cdec9c7f3: Waiting
fce5728aad85: Downloading [> ] 185.7kB/18.54MB
fce5728aad85: Downloading [=> ] 371.9kB/18.54MB
76610ec20bf5: Downloading [> ] 425.1kB/42.5MB
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fce5728aad85: Downloading [====> ]
49e2d6393f32: Downloading [=========================================> ] 108.1MB/130.1MB
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49e2d6393f32: Downloading [=================================================> ] 129.7MB/130.1MB
49e2d6393f32: Verifying Checksum
49e2d6393f32: Download complete
49e2d6393f32: Extracting [> ] 557.1kB/130.1MB
49e2d6393f32: Extracting [> ] 1.671MB/130.1MB
49e2d6393f32: Extracting [=> ] 2.785MB/130.1MB
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49e2d6393f32: Extracting [===============================================> ] 122.6MB/130.1MB
49e2d6393f32: Extracting [===============================================> ] 123.7MB/130.1MB
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49e2d6393f32: Extracting [==================================================>] 130.1MB/130.1MB
49e2d6393f32: Pull complete
bb9cdec9c7f3: Extracting [=====> ] 32.77kB/289kB
bb9cdec9c7f3: Extracting [==================================================>] 289kB/289kB
bb9cdec9c7f3: Extracting [==================================================>] 289kB/289kB
bb9cdec9c7f3: Pull complete
?[0BDigest: sha256:c1ff613e8ba25833d2e1940da0940c3824f03f802c449f3d1815a66b7f8c0e9d
Status: Downloaded newer image for java:latest
---> d23bdf5b1b1b
Step 2/3 : ADD /cloud-eureka-1.0.jar //
---> 11356e5b9dea
Step 3/3 : ENTRYPOINT ["java", "-jar", "/cloud-eureka-1.0.jar"]
---> Running in 710837e5de27
Removing intermediate container 710837e5de27
---> 2bddac8bfef7
ProgressMessage{id=null, status=null, stream=null, error=null, progress=null, progressDetail=null}
Successfully built 2bddac8bfef7
Successfully tagged cloud-demo/cloud-eureka:1.0
[INFO] Built cloud-demo/cloud-eureka:1.0
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 03:13 min
[INFO] Finished at: 2019-10-19T22:31:44+08:00
[INFO] Final Memory: 72M/555M
[INFO] ------------------------------------------------------------------------
由以上日志可知，已成功构建了一个Docker镜像。
- 执行docker images命令，即可查看刚刚构建的镜像。
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
cloud-demo/cloud-eureka 1.0 2bddac8bfef7 10 minutes ago 687MB
- 启动以下镜像：
$ docker run -d -p 8888:8888 cloud-demo/cloud-eureka:1.0
9105eacca9aa7dc01d6285aef9571b1397c70040bdb691515fe2d3b9e2c66882
- 访问测试
访问 http://Docker 宿主机IP:8888，能够看到Eureka Server的首页。
我们这里访问 http://192.168.99.100:8888/
使用Maven插件读取Dockerfile进行构建
之前的示例直接在pom.xml中设置了一些构建的参数。很多场景下希望使用Dockerfile更精确、有可读性地构建镜像。
- 首先在/cloud-eureka/src/main/docker目录下，新建一个Dockerfile文件
FROM java:8
VOLUME /tmp
ADD cloud-eureka-1.0.jar app.jar
RUN bash -c 'touch /app.jar'
EXPOSE 8888
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]
VOLUME 指定挂载点
- 该指令使容器中的一个目录具有持久化存储的功能，该目录可被容器本身使用，也可共享给其他容器。当容器中的应用有持久化数据的需求时可以在Dockerfile中使用该指令。
ADD复制文件
- ADD指令用于复制文件
EXPOSE声明暴露的端口
- EXPOSE指令用于声明在运行时容器提供服务的端口
- 修改pom.xml
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<version>0.4.13</version>
<configuration>
<imageName>cloud-demo/${project.artifactId}:${project.version}</imageName>
<dockerDirectory>${project.basedir}/src/main/docker</dockerDirectory>
<resources>
<resource>
<targetPath>/</targetPath>
<directory>${project.build.directory}</directory>
<include>${project.build.finalName}.jar</include>
</resource>
</resources>
</configuration>
</plugin>
可以看到，不再指定baselImage和entrypoint，而是使用dockerDirectory指定Dockerfile所在的路径。这样，就可以使用Dockerfile构建Docker镜像了。
- 使用如下命令构建Docker镜像
C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka>mvn clean package docker:build
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building cloud-eureka 1.0
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:3.1.0:clean (default-clean) @ cloud-eureka ---
[INFO] Deleting C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target
[INFO]
[INFO] --- maven-resources-plugin:3.1.0:resources (default-resources) @ cloud-eureka ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.8.0:compile (default-compile) @ cloud-eureka ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\classes
[INFO]
[INFO] --- maven-resources-plugin:3.1.0:testResources (default-testResources) @ cloud-eureka ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\src\test\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.8.0:testCompile (default-testCompile) @ cloud-eureka ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-surefire-plugin:2.22.1:test (default-test) @ cloud-eureka ---
[INFO] No tests to run.
[INFO]
[INFO] --- maven-jar-plugin:3.1.0:jar (default-jar) @ cloud-eureka ---
[INFO] Building jar: C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\cloud-eureka-1.0.jar
[INFO]
[INFO] --- spring-boot-maven-plugin:2.1.1.RELEASE:repackage (repackage) @ cloud-eureka ---
[INFO] Replacing main artifact with repackaged archive
[INFO]
[INFO] --- docker-maven-plugin:0.4.13:build (default-cli) @ cloud-eureka ---
[INFO] Copying C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\cloud-eureka-1.0.jar -> C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\docker\cloud-eu
reka-1.0.jar
[INFO] Copying C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\src\main\docker\Dockerfile -> C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\docker\Dockerfil
e
[INFO] Building image cloud-demo/cloud-eureka:1.0
Step 1/6 : FROM java:8
---> d23bdf5b1b1b
Step 2/6 : VOLUME /tmp
---> Running in 13880234da8c
Removing intermediate container 13880234da8c
---> f7fd43313aa4
Step 3/6 : ADD cloud-eureka-1.0.jar app.jar
---> 97ea89c50ce4
Step 4/6 : RUN bash -c 'touch /app.jar'
---> Running in 4d22bd44a2e2
Removing intermediate container 4d22bd44a2e2
---> cf215d997e1f
Step 5/6 : EXPOSE 8888
---> Running in 69445855b134
Removing intermediate container 69445855b134
---> bc31140fabd9
Step 6/6 : ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]
---> Running in c8b6f5d2e1a2
Removing intermediate container c8b6f5d2e1a2
---> 25404f35b2ab
ProgressMessage{id=null, status=null, stream=null, error=null, progress=null, progressDetail=null}
Successfully built 25404f35b2ab
Successfully tagged cloud-demo/cloud-eureka:1.0
[INFO] Built cloud-demo/cloud-eureka:1.0
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 16.740 s
[INFO] Finished at: 2019-10-20T13:05:05+08:00
[INFO] Final Memory: 64M/556M
[INFO] ------------------------------------------------------------------------
- 测试访问 http://192.168.99.100:8888/
将插件绑定在某个phase执行
很多场景下，有这样的需求，执行例如mvn clean package时，插件就自动为构建 Docker镜像。要想实现这点，只须将插件的goal绑定在某个phase即可。
phase和goal可以这样理解：maven命令格式是：mvn phase:goal，例如mvn package docker
:build。那么，package和docker都是phase，build则是goal。示例：
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<version>0.4.13</version>
<executions>
<execution>
<id>build-image</id>
<phase>package</phase>
<goals>
<goal>build</goal>
</goals>
</execution>
</executions>
<configuration>
<imageName>cloud-demo/${project.artifactId}:${project.version}</imageName>
<dockerDirectory>${project.basedir}/src/main/docker</dockerDirectory>
<resources>
<resource>
<targetPath>/</targetPath>
<directory>${project.build.directory}</directory>
<include>${project.build.finalName}.jar</include>
</resource>
</resources>
</configuration>
</plugin>
由配置可知，只须添加如下配置：
<executions>
<execution>
<id>build-image</id>
<phase>package</phase>
<goals>
<goal>build</goal>
</goals>
</execution>
</executions>
就可将插件绑定在package这个phase上。也就是说，用户只须执行mvn package，就会自动执行mvn docker:build。当然，读者也可按照需求，将插件绑定到其他的phase。
然后我们执行如下命令就可以进行构建了。
C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka>mvn clean package
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building cloud-eureka 1.0
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:3.1.0:clean (default-clean) @ cloud-eureka ---
[INFO] Deleting C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target
[INFO]
[INFO] --- maven-resources-plugin:3.1.0:resources (default-resources) @ cloud-eureka ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.8.0:compile (default-compile) @ cloud-eureka ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\classes
[INFO]
[INFO] --- maven-resources-plugin:3.1.0:testResources (default-testResources) @ cloud-eureka ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\src\test\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.8.0:testCompile (default-testCompile) @ cloud-eureka ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-surefire-plugin:2.22.1:test (default-test) @ cloud-eureka ---
[INFO] No tests to run.
[INFO]
[INFO] --- maven-jar-plugin:3.1.0:jar (default-jar) @ cloud-eureka ---
[INFO] Building jar: C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\cloud-eureka-1.0.jar
[INFO]
[INFO] --- spring-boot-maven-plugin:2.1.1.RELEASE:repackage (repackage) @ cloud-eureka ---
[INFO] Replacing main artifact with repackaged archive
[INFO]
[INFO] --- docker-maven-plugin:0.4.13:build (build-image) @ cloud-eureka ---
[INFO] Copying C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\cloud-eureka-1.0.jar -> C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\docker\cloud-eu
reka-1.0.jar
[INFO] Copying C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\src\main\docker\Dockerfile -> C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka\target\docker\Dockerfil
e
[INFO] Building image cloud-demo/cloud-eureka:1.0
Step 1/6 : FROM java:8
---> d23bdf5b1b1b
Step 2/6 : VOLUME /tmp
---> Using cache
---> f7fd43313aa4
Step 3/6 : ADD cloud-eureka-1.0.jar app.jar
---> e742c02ab4a0
Step 4/6 : RUN bash -c 'touch /app.jar'
---> Running in 1f5ab28f9f32
Removing intermediate container 1f5ab28f9f32
---> edd847fd6a8b
Step 5/6 : EXPOSE 8888
---> Running in 9190d4137a96
Removing intermediate container 9190d4137a96
---> 4e557d99ebca
Step 6/6 : ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]
---> Running in d2d566d49093
Removing intermediate container d2d566d49093
---> 96101741ff95
ProgressMessage{id=null, status=null, stream=null, error=null, progress=null, progressDetail=null}
Successfully built 96101741ff95
Successfully tagged cloud-demo/cloud-eureka:1.0
[INFO] Built cloud-demo/cloud-eureka:1.0
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 19.664 s
[INFO] Finished at: 2019-10-20T18:20:16+08:00
[INFO] Final Memory: 64M/581M
[INFO] ------------------------------------------------------------------------
C:\Users\c\Desktop\spring-cloud-demo\cloud-eureka>
参考
SecureRandom生成随机数超慢 导致tomcat启动时间过长的解决办法
SecureRandom产生随机数性能优化 -Djava.security.egd=file:/dev/./urandom
Maven学习笔记（一）——自定义maven变量以及maven内置常量
What is the value of project.build.finalName?
源代码
https://gitee.com/cckevincyh/spring-cloud-demo/tree/config-refactor/
https://gitee.com/cckevincyh/spring-cloud-demo/tree/release-docker/
https://gitee.com/cckevincyh/spring-cloud-demo/tree/release-docker-dockerfile/
