Docker与Jib(maven插件版)实战

### 欢迎访问我的GitHub > 这里分类和汇总了欣宸的全部原创(含配套源码)：[https://github.com/zq2599/blog_demos](https://github.com/zq2599/blog_demos) ### 关于Jib - Java应用如果要运行在docker环境，就要制作包含该应用的docker镜像，Jib就是用来制作此镜像的的工具，有三种使用Jib的方法： 1. Maven插件：jib-maven-plugin； 2. Gradle插件：jib-gradle-plugin； 3. Java库：Jib Core； - Jib的官网地址是：https://github.com/GoogleContainerTools/jib - 今天咱们要聊的是第一种：通过jib的maven插件将java应用构建成docker镜像； ### 实战环境信息 1. 操作系统：CentOS Linux release 7.6.1810 2. docker：1.13.1 3. jdk：1.8.0_191 4. maven：3.6.0 - 接下来一起开发一个java应用，并使用jib的maven插件，来构建该应用对应的docker镜像； ### 源码下载 - 如果您不打算写代码，也可以从GitHub上下载本次实战的源码，地址和链接信息如下表所示： | 名称 | 链接 | 备注| | :-------- | :----| :----| | 项目主页| https://github.com/zq2599/blog_demos | 该项目在GitHub上的主页 | | git仓库地址(https)| https://github.com/zq2599/blog_demos.git | 该项目源码的仓库地址，https协议 | | git仓库地址(ssh)| [e-mail]:zq2599/blog_demos.git | 该项目源码的仓库地址，ssh协议 | - 这个git项目中有多个文件夹，本章的源码在hellojib文件夹下，如下图红框所示：  ### 准备java应用 - 准备一个最简单的springboot应用hellojib，用于实战构建docker镜像； - 该应用是基于maven构建的，启动类如下： ```java package com.bolingcavalry.hellojib; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class HellojibApplication { public static void main(String[] args) { SpringApplication.run(HellojibApplication.class, args); } } ``` - 有一个controller用于后面验证服务是否正常： ```java package com.bolingcavalry.hellojib.controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import java.text.SimpleDateFormat; import java.util.Date; /** * @Description: 普通的controller * @author: willzhao E-mail: [e-mail] * @date: 2019/6/29 20:21 */ @RestController public class HelloController { @RequestMapping("/hello") public String hello(){ return "Hello, " + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()); } } ``` - **最重要的部分来了** ，pom.xml的内容如下，请注意注释： ```xml <?xml version="1.0" encoding="UTF-8"?><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemalocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelversion>4.0.0</modelversion><parent><groupid>org.springframework.boot</groupid><artifactid>spring-boot-starter-parent</artifactid><version>2.1.6.RELEASE</version><relativepath></relativepath></parent><groupid>com.bolingcavalry</groupid><artifactid>hellojib</artifactid><version>0.0.1-SNAPSHOT</version><name>hellojib</name><description>Demo project for Spring Boot</description><properties><java.version>1.8</java.version></properties><dependencies><dependency><groupid>org.springframework.boot</groupid><artifactid>spring-boot-starter-web</artifactid></dependency><dependency><groupid>org.springframework.boot</groupid><artifactid>spring-boot-starter-test</artifactid><scope>test</scope></dependency></dependencies><build><plugins><plugin><groupid>org.springframework.boot</groupid><artifactid>spring-boot-maven-plugin</artifactid></plugin><plugin><groupid>com.google.cloud.tools</groupid><artifactid>jib-maven-plugin</artifactid><version>1.3.0</version><configuration><from><image>openjdk:8-jdk-stretch</image></from><to><image>bolingcavalry/hellojib:${project.version}</image></to><container><jvmflags><jvmflag>-Xms4g</jvmflag><jvmflag>-Xmx4g</jvmflag></jvmflags><ports><port>8080</port></ports></container></configuration></plugin></plugins></build></project> ``` - 上述xml中有以下几处需要注意： a. 插件的节点中增加了插件jib-maven-plugin的配置； b. from节点用来设置基础镜像，一般使用openjdk官方镜像，如果您想了解更多请参考[《openjdk镜像的tag说明》](https://blog.csdn.net/boling_cavalry/article/details/94320638)； c. to节点用于指定镜像名称和tag； d. container节点用来设置容器的属性，例如对外暴露的端口、jvm参数等； - 完成了上述设置，就可以构建镜像了； ### 构建成tar文件 - 还记得常用的docker到处到处命令么： - **docker save** 命令将本地仓库的docker镜像导出成tar格式的文件； - **docker load** 命令可以将tar格式的镜像文件导入到本地镜像仓库； - 利用Jib，我们可以将java应用做成docker镜像并生成tar格式的文件，操作步骤如下： - 在上述java工程的pom.xml文件所在目录，执行以下命令： ```shell mvn compile jib:buildTar ``` - 构建成功后，控制台提示以下信息： ```shell [root@centos7 hellojib]# mvn compile jib:buildTar [INFO] Scanning for projects... [INFO] [INFO] ------------------------------------------ [INFO] Building hellojib 0.0.1-SNAPSHOT [INFO] --------------------------------[ jar ]--------------------------------- [INFO] [INFO] --- maven-resources-plugin:3.1.0:resources (default-resources) @ hellojib --- [INFO] Using 'UTF-8' encoding to copy filtered resources. [INFO] Copying 1 resource [INFO] Copying 0 resource [INFO] [INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ hellojib --- [INFO] Nothing to compile - all classes are up to date [INFO] [INFO] --- jib-maven-plugin:1.3.0:buildTar (default-cli) @ hellojib --- [INFO] [INFO] Containerizing application to file at '/root/temp/201906/29/hellojib/target/jib-image.tar'... [INFO] The base image requires auth. Trying again for openjdk:8-jdk-stretch... [INFO] [INFO] Container entrypoint set to [java, -Xms4g, -Xmx4g, -cp, /app/resources:/app/classes:/app/libs/*, com.bolingcavalry.hellojib.HellojibApplication] [INFO] [INFO] Built image tarball at /root/temp/201906/29/hellojib/target/jib-image.tar [INFO] Executing tasks: [INFO] [==============================] 100.0% complete [INFO] [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 16.521 s [INFO] Finished at: 2019-06-30T21:43:32+08:00 [INFO] ------------------------------------------------------------------------ ``` - 去java工程的target目录下，发现生成了名为jib-image.tar的文件，如下图红框所示：  - 在java工程的target目录下执行命令 **docker load ] 50.07 MB/50.07 MB ea20c4bf3aae: Loading layer [==================================================>] 4.932 MB/4.932 MB 51774d97c868: Loading layer [==================================================>] 221 B/221 B 51566e3f832b: Loading layer [==================================================>] 104 MB/104 MB 64c0b8425948: Loading layer [==================================================>] 14.91 MB/14.91 MB e4c3b920750d: Loading layer [==================================================>] 240 B/240 B 8917d4e7f7b3: Loading layer [==================================================>] 1.034 kB/1.034 kB Loaded image: bolingcavalry/hellojib:0.0.1-SNAPSHOT ``` - 执行命令 **docker images** 可见镜像加载成功： ```shell [root@centos7 target]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE bolingcavalry/hellojib 0.0.1-SNAPSHOT cf93bd81fbd5 49 years ago 505 MB ``` - 可见通过jib生成的tar是正常的docker镜像文件，可以导入 ### 验证镜像是否可用 - 执行以下命令，即可启动容器： ```shell docker run --rm -p 8080:8080 bolingcavalry/hellojib:0.0.1-SNAPSHOT ``` - 控制台显示springboot的启动信息： ```shell [root@centos7 target]# docker run --rm -p 8080:8080 bolingcavalry/hellojib:0.0.1-SNAPSHOT . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v2.1.6.RELEASE) 2019-06-30 13:56:50.969 INFO 1 --- [ main] c.b.hellojib.HellojibApplication : Starting HellojibApplication on c08711533071 with PID 1 (/app/classes started by root in /) 2019-06-30 13:56:50.975 INFO 1 --- [ main] c.b.hellojib.HellojibApplication : No active profile set, falling back to default profiles: default 2019-06-30 13:56:52.147 INFO 1 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http) 2019-06-30 13:56:52.173 INFO 1 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat] 2019-06-30 13:56:52.173 INFO 1 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.21] 2019-06-30 13:56:52.261 INFO 1 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2019-06-30 13:56:52.261 INFO 1 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1223 ms 2019-06-30 13:56:52.475 INFO 1 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor' 2019-06-30 13:56:52.772 INFO 1 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path '' 2019-06-30 13:56:52.811 INFO 1 --- [ main] c.b.hellojib.HellojibApplication : Started HellojibApplication in 2.202 seconds (JVM running for 2.446) ``` - 用浏览器访问：http://192.168.121.132:8080/hello ，其中 **192.168.121.132** 是宿主机IP地址，如下图，可见springboot服务可以正常访问：  ### 构建到本地镜像仓库 - 上面的操作是将java应用生成tar文件然后再导入到本地镜像仓库，您也可以直接将java应用构建到本地镜像仓库中： - 先执行命令 **docker rmi bolingcavalry/hellojib:0.0.1-SNAPSHOT** 将前面构建的镜像删除； - 在pom.xml文件所在目录执行以下命令即可： ```shell mvn clean compile jib:dockerBuild -U ``` - 终端提示如下： ```shell [root@centos7 hellojib]# mvn clean compile jib:dockerBuild -U [INFO] Scanning for projects... [INFO] [INFO] ------------------------------------------ [INFO] Building hellojib 0.0.1-SNAPSHOT [INFO] --------------------------------[ jar ]--------------------------------- [INFO] [INFO] --- maven-clean-plugin:3.1.0:clean (default-clean) @ hellojib --- [INFO] Deleting /root/temp/201906/29/hellojib/target [INFO] [INFO] --- maven-resources-plugin:3.1.0:resources (default-resources) @ hellojib --- [INFO] Using 'UTF-8' encoding to copy filtered resources. [INFO] Copying 1 resource [INFO] Copying 0 resource [INFO] [INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ hellojib --- [INFO] Changes detected - recompiling the module! [INFO] Compiling 2 source files to /root/temp/201906/29/hellojib/target/classes [INFO] [INFO] --- jib-maven-plugin:1.3.0:dockerBuild (default-cli) @ hellojib --- [INFO] [INFO] Containerizing application to Docker daemon as bolingcavalry/hellojib:0.0.1-SNAPSHOT... [INFO] The base image requires auth. Trying again for openjdk:8-jdk-stretch... [INFO] [INFO] Container entrypoint set to [java, -Xms4g, -Xmx4g, -cp, /app/resources:/app/classes:/app/libs/*, com.bolingcavalry.hellojib.HellojibApplication] [INFO] [INFO] Built image to Docker daemon as bolingcavalry/hellojib:0.0.1-SNAPSHOT [INFO] Executing tasks: [INFO] [==============================] 100.0% complete [INFO] [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 20.923 s [INFO] Finished at: 2019-06-30T22:04:36+08:00 [INFO] ------------------------------------------------------------------------ ``` - 执行命令 **docker images** 可见镜像已经在镜像仓库中了： ```shell [root@centos7 hellojib]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE bolingcavalry/hellojib 0.0.1-SNAPSHOT cf93bd81fbd5 49 years ago 505 MB ``` ### 构建到hub.docker.com - docker的*仓库是 hub.docker.com ，jib也可以在镜像构建成功后自动推送到hub.docker.com网站，前提是您已经在该网站注册过，例如我已经注册过，账号是 **bolingcavalry** ，因此名为 **bolingcavalry/XXXXXXXX** 的镜像都可以推送到 hub.docker.com： - 在pom.xml文件所在目录执行以下命令即可自动推送到 hub.docker.com，其中bolingcavalry是我在hub.docker.com上的注册账号，123456是密码： ```shell mvn compile jib:build -Djib.to.auth.username=bolingcavalry -Djib.to.auth.password=123456 ``` - 终端信息如下： ```shell [root@centos7 hellojib]# mvn compile jib:build -Djib.to.auth.username=bolingcavalry -Djib.to.auth.password=123456 [INFO] Scanning for projects... [INFO] [INFO] ------------------------------------------ [INFO] Building hellojib 0.0.1-SNAPSHOT [INFO] --------------------------------[ jar ]--------------------------------- [INFO] [INFO] --- maven-resources-plugin:3.1.0:resources (default-resources) @ hellojib --- [INFO] Using 'UTF-8' encoding to copy filtered resources. [INFO] Copying 1 resource [INFO] Copying 0 resource [INFO] [INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ hellojib --- [INFO] Nothing to compile - all classes are up to date [INFO] [INFO] --- jib-maven-plugin:1.3.0:build (default-cli) @ hellojib --- [INFO] [INFO] Containerizing application to bolingcavalry/hellojib:0.0.1-SNAPSHOT... [INFO] The base image requires auth. Trying again for openjdk:8-jdk-stretch... [INFO] [INFO] Container entrypoint set to [java, -Xms4g, -Xmx4g, -cp, /app/resources:/app/classes:/app/libs/*, com.bolingcavalry.hellojib.HellojibApplication] [INFO] [INFO] Built and pushed image as bolingcavalry/hellojib:0.0.1-SNAPSHOT [INFO] Executing tasks: [INFO] [==============================] 100.0% complete [INFO] [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 02:47 min [INFO] Finished at: 2019-06-30T22:16:19+08:00 [INFO] ------------------------------------------------------------------------ ``` - 在hub.docker.com上已经可以看到此镜像了，如下图（要登录后再看自己的镜像列表，如果没有登录是无法立即查到的）：  - 至此，Jib的实战已经完成，常用的操作相信您已经熟悉了，希望本文能帮助您做出满意的镜像； ### 欢迎关注ITpub：程序员欣宸 > [学习路上，你不孤单，欣宸原创一路相伴...](http://blog.itpub.net/70017844/)