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本文主要研究一下如何使用google的jib打包docker镜像
Jib 是谷歌最新开源的 Java 应用的 Docker 镜像生成工具，可以通过 Gradle 或 Maven 直接生成镜像并上传到仓库而不需要 Dockerfile 文件或者其他插件；Jib 支持将资源文件和类分层打包，可以大幅度提升生成镜像的速度
有一些其他的插件也可以通过 Docker 实现生成镜像，如com.palantir.docker等，但是都需要额外配置 Dockerfile, 如果应用仅需要通过 Dockerfile 构建镜像，建议使用 Jib 来提升构建和上传速度
maven
<plugin> <groupId>com.google.cloud.tools</groupId> <artifactId>jib-maven-plugin</artifactId> <version>0.9.9</version> </plugin>
配置
<properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <maven.build.timestamp.format>yyyyMMdd</maven.build.timestamp.format> </properties> <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>0.9.9</version> <configuration> <container> <jvmFlags> <jvmFlag>-Xms512m</jvmFlag> </jvmFlags> <ports> <port>8080</port> </ports> <useCurrentTimestamp>true</useCurrentTimestamp> </container> <from> <image>java:8u172-jre-alpine</image> </from> <to> <image>jib-demo:${maven.build.timestamp}</image> </to> <allowInsecureRegistries>true</allowInsecureRegistries> <extraDirectory>${project.basedir}/src/main/jib</extraDirectory> </configuration> </plugin> </plugins> </build> 这里指定base image为java:8u172-jre-alpine
同时指定生成的image名称为jib-demo:${maven.build.timestamp}
container标签可以指定相关参数，比如jvmFlags指定JVM参数，ports指定expose的端口号
extraDirectory用于指定要添加的目录，默认为${project.basedir}/src/main/jib，即该目录下的文件夹会在docker镜像里头同步创建，目录层级关系以jib下目录层级关系为准。比如该目录下有app/resources/demo.txt，则对应该镜像目录为/app/resources/demo.txt
打包
mvn compile jib:dockerBuild -X
使用jib:dockerBuild是在本地打包镜像，不push到远程，-X参数是显示debug信息
如果使用jib:build命令，则打包之后push到远程
输出日志实例：
[DEBUG] TIMING Building image to Docker daemon[DEBUG] RUNNING Building image to Docker daemon[INFO] Getting base image java:8u172-jre-alpine...[DEBUG] TIMING Pulling base image manifest[DEBUG] RUNNING Pulling base image manifest[DEBUG] TIMING Building application layers[DEBUG] RUNNING Building application layers[INFO] Building dependencies layer...[DEBUG] TIMING Building dependencies layer[DEBUG] RUNNING Building dependencies layer[INFO] Building resources layer...[DEBUG] TIMING Building resources layer[DEBUG] RUNNING Building resources layer[INFO] Building classes layer...[DEBUG] TIMING Building classes layer[DEBUG] RUNNING Building classes layer[INFO] Building extra files layer...[DEBUG] TIMING Building extra files layer[DEBUG] RUNNING Building extra files layer[DEBUG] TIMED Building application layers : 3.498 ms[DEBUG] Building application layers : 3.498 ms[DEBUG] Building extra files layer built sha256:0a9321c621ee2c138d9a93f4ba47f825e20dd7aca0e9206f30bf560122fdaa31[DEBUG] Building resources layer built sha256:933116c8da4db70000355b750af2f3b5c4545e74db7b5eb0a5e37689ef86d44f[DEBUG] Building classes layer built sha256:a99dbde7d015ba3d15b9265ac38f6536d65b00dd2a864b7003a34742f483939b[DEBUG] TIMED Building extra files layer : 33.718 ms[DEBUG] TIMED Building classes layer : 33.901 ms[DEBUG] Building extra files layer : 33.718 ms[DEBUG] TIMED Building resources layer : 34.062 ms[DEBUG] Building resources layer : 34.062 ms[DEBUG] Building classes layer : 33.901 ms[DEBUG] Building dependencies layer built sha256:a19961ec08095eb70ca3a070945223dcf51500a255a745272276139bf0a29f4e[DEBUG] TIMED Building dependencies layer : 1047.83 ms[DEBUG] Building dependencies layer : 1047.83 ms[INFO] The base image requires auth. Trying again for java:8u172-jre-alpine...//......[DEBUG] TIMED Pulling base image manifest : 8959.891 ms[DEBUG] Pulling base image manifest : 8959.891 ms[DEBUG] TIMING Setting up base image caching[DEBUG] RUNNING Setting up base image caching[DEBUG] TIMED Setting up base image caching : 0.824 ms[DEBUG] Setting up base image caching : 0.824 ms[DEBUG] TIMING Pulling base image layer sha256:500c0ac4cdc58aee9a008e70466eeec8a4b74b25c29d003764635d2fe1b42827[DEBUG] RUNNING Pulling base image layer sha256:500c0ac4cdc58aee9a008e70466eeec8a4b74b25c29d003764635d2fe1b42827[DEBUG] TIMING Pulling base image layer sha256:aa38cd8c77d7320c7489327775e074580db5f23467198aab3e79c7db5cdfbdca[DEBUG] TIMING Pulling base image layer sha256:cb56d62302ec31640b40ca15843e7af6be145966a1064c78ea7afd6f10ce49e6[DEBUG] RUNNING Pulling base image layer sha256:cb56d62302ec31640b40ca15843e7af6be145966a1064c78ea7afd6f10ce49e6[DEBUG] TIMING Pulling base image layer sha256:ff3a5c916c92643ff77519ffa742d3ec61b7f591b6b7504599d95a4a41134e28[DEBUG] RUNNING Pulling base image layer sha256:ff3a5c916c92643ff77519ffa742d3ec61b7f591b6b7504599d95a4a41134e28[DEBUG] RUNNING Pulling base image layer sha256:aa38cd8c77d7320c7489327775e074580db5f23467198aab3e79c7db5cdfbdca[DEBUG] TIMED Pulling base image layer sha256:500c0ac4cdc58aee9a008e70466eeec8a4b74b25c29d003764635d2fe1b42827 : 612.524 ms[DEBUG] Pulling base image layer sha256:500c0ac4cdc58aee9a008e70466eeec8a4b74b25c29d003764635d2fe1b42827 : 612.524 ms[DEBUG] TIMED Pulling base image layer sha256:ff3a5c916c92643ff77519ffa742d3ec61b7f591b6b7504599d95a4a41134e28 : 9985.702 ms[DEBUG] Pulling base image layer sha256:ff3a5c916c92643ff77519ffa742d3ec61b7f591b6b7504599d95a4a41134e28 : 9985.702 ms[DEBUG] TIMED Pulling base image layer sha256:aa38cd8c77d7320c7489327775e074580db5f23467198aab3e79c7db5cdfbdca : 27267.144 ms[DEBUG] Pulling base image layer sha256:aa38cd8c77d7320c7489327775e074580db5f23467198aab3e79c7db5cdfbdca : 27267.144 ms[DEBUG] TIMED Pulling base image layer sha256:cb56d62302ec31640b40ca15843e7af6be145966a1064c78ea7afd6f10ce49e6 : 54734.971 ms[DEBUG] Pulling base image layer sha256:cb56d62302ec31640b40ca15843e7af6be145966a1064c78ea7afd6f10ce49e6 : 54734.971 ms[DEBUG] TIMING Building container configuration[DEBUG] RUNNING Building container configuration[INFO] Finalizing...[DEBUG] TIMED Building container configuration : 0.462 ms[DEBUG] Building container configuration : 0.462 ms[INFO] Loading to Docker daemon...[DEBUG] TIMED Building image to Docker daemon : 65862.956 ms[DEBUG] Building image to Docker daemon : 65862.956 ms[INFO][INFO] Container entrypoint set to [java, -Xms512m, -cp, /app/resources/:/app/classes/:/app/libs/*, com.example.JibDemoApplication][INFO][INFO] Built image to Docker daemon as jib-demo:20180826[INFO][INFO] ------------------------------------------------------------------------[INFO] BUILD SUCCESS[INFO] ------------------------------------------------------------------------[INFO] Total time: 01:07 min[INFO] Finished at: 2018-08-26T21:38:11+08:00[INFO] Final Memory: 26M/493M[INFO] ------------------------------------------------------------------------
查看镜像
docker inspect jib-demo:20180826[ { "Id": "sha256:7554492dde84091bc6d015b29ec4bf854bb841b9ec4d8f7bef8b51a8ec59ef94", "RepoTags": [ "jib-demo:20180826" ], "RepoDigests": [], "Parent": "", "Comment": "", "Created": "2018-08-26T13:37:05.65Z", "Container": "", "ContainerConfig": { "Hostname": "", "Domainname": "", "User": "", "AttachStdin": false, "AttachStdout": false, "AttachStderr": false, "Tty": false, "OpenStdin": false, "StdinOnce": false, "Env": null, "Cmd": null, "Image": "", "Volumes": null, "WorkingDir": "", "Entrypoint": null, "OnBuild": null, "Labels": null }, "DockerVersion": "", "Author": "", "Config": { "Hostname": "", "Domainname": "", "User": "", "AttachStdin": false, "AttachStdout": false, "AttachStderr": false, "ExposedPorts": { "8080/tcp": {} }, "Tty": false, "OpenStdin": false, "StdinOnce": false, "Env": [ "PATH=/opt/jdk1.8.0_172/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", "JAVA_HOME=/opt/jdk1.8.0_172" ], "Cmd": [], "Image": "", "Volumes": null, "WorkingDir": "", "Entrypoint": [ "java", "-Xms512m", "-cp", "/app/resources/:/app/classes/:/app/libs/*", "com.example.JibDemoApplication" ], "OnBuild": null, "Labels": {} }, "Architecture": "amd64", "Os": "linux", "Size": 186079594, "VirtualSize": 186079594, "GraphDriver": { "Data": null, "Name": "aufs" }, "RootFS": { "Type": "layers", "Layers": [ "sha256:cd7100a72410606589a54b932cabd804a17f9ae5b42a1882bd56d263e02b6215", "sha256:317e0b42ef29551507adc792c2dbc389af85c5d68900cf0f08abe907cbd4e199", "sha256:d6fd5302a9ee64c43b46153e9678153819d6d0e247381acbbe6cbe6ed9de0366", "sha256:417c6bd0930eb69d17ae5d601898a6a012900ca33c69e612840a3042b2451cbb", "sha256:8309a5eed5158c5639acb664312ddc7027a2ecb172744f548d6d9fb5f918a744", "sha256:6ef8c795d7a5e2a07f51d572a90b820e089f89adf30798193f4f3f410a261415", "sha256:9990447f3d37e3f2dc70718d0ea6602cf7843091d8bbe395f552c9c5dd10551c", "sha256:ff7910aaeee962d1d86e00742030378a2758da59d8c8cda3fe44314bbddd8081" ] }, "Metadata": { "LastTagTime": "0001-01-01T00:00:00Z" } }] 可以看到java -cp指定了/app/libs/、/app/resources/、/app/classes/这三个文件夹
小结
jib默认执行如下操作
COPY libs /app/libs/COPY resources /app/resources/COPY classes /app/classes/
也就是将libs拷贝到/app/libs，将resources拷贝到/app/resources，将classes拷贝到/app/classes.
doc
- jib
- Building Docker Image for a Spring Boot App With Jib
- build-containers-faster-with-jib-a-google-image-build-tool-for-java-applications
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持VEVB武林网。
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