dockerfile-maven-plugin極簡教程(推薦)
一、簡介
maven是一個專案依賴管理和構建的工具,dockerfile-maven-plugin是一個maven的外掛,主要作用是在專案構建的時候生成基於專案的docker映象檔案。
簡而言之,此外掛將maven和docker進行整合。
正常情況下,我們在開發了一個應用程式後,會使用maven進行打包,生成對應的jar檔案。而後,會使用docker將jar檔案build成一個映象(docker image)。之後,就可以在docker daemon中建立基於映象的容器,並可提供服務了。
dockerfile-maven-plugin的目標就是將maven的打包過程和docker的build過程結合在一起,當成功打包,既生成了對應的jar,也已生成了對應的docker映象。當然,這只是最基礎的功能,更詳細的功能參見:https://github.com/spotify/dockerfile-maven
二、概述
我們知道maven是apache公司開發的一個產品,但是dockerfile-maven-plugin並不是apache官方開發的外掛,是由一個叫做Spotify的組織開發的。
github主頁:https://spotify.github.io/
github開源地址:https://github.com/spotify/dockerfile-maven
本文僅討論如何基於一個Spring Boot的專案生成對應的docker映象。
基本的原理如下:
- 首先,dockerfile-maven-plugin外掛已經儲存在maven的倉庫中
- 然後,當在本地開發的時候,需要在專案的pom檔案中引入此外掛,在pom-build-plugins下面增加plugin配置節點
- 再然後,在executions節點中配置此外掛如何工作;並且在configuration節點中加入需要的配置資訊
- 最後,當我們執行mvn package的時候就可以得到docker image 了
環境:
- Ideal版本:2020.01
- java版本:8
- maven版本:3.6.1
- docker版本:19.03.12
ideal和docker deamon執行在同一臺機器上面
三、將spring-boot-app打包成docker映象
建立示例應用
使用ideal自帶的Spring Initializr生成一個Spring Web 的示例專案
app對外提供一個hello的介面,訪問該介面可以得到Hello,World的響應結果。應用主啟動類程式碼如下:
package com.naylor.dockerfilemavenplugin; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController @RequestMapping("/") @SpringBootApplication public class DockerfileMavenPluginApplication { public static void main(String[] args) { SpringApplication.run(DockerfileMavenPluginApplication.class,args); } @GetMapping("/hello") public String hello(){ return "Hello,World"; } }
編譯並執行專案,在瀏覽器中訪問「http://127.0.0.1:8080/hello」 可以得到預期的響應結果
修改pom檔案
在pom中增加對dockerfile-maven-plugin外掛的引用,核心程式碼如下:
<!-- dockerfile-maven-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> </goals> </execution> </executions> <configuration> <repository>com.naylor/${project.artifactId}</repository> <tag>${project.version}</tag> <buildArgs> <JAR_FILE>${project.build.finalName}.jar</JAR_FILE> </buildArgs> </configuration> </plugin>
其中:
- g,a,v 為對外掛的引用
- executions中的build標識,在maven的packege環節執行此外掛
- configuration中的repository是生成的映象的repository資訊
- tag為映象的tag資訊
- buildArgs是在docker構建映象過程中的引數,此處定義的JAR_FILE引數在執行docker build 的時候會消費
完整的pom檔案如下:
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.3.4.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.naylor</groupId> <artifactId>dockerfile-maven-plugin</artifactId> <version>0.0.1-SNAPSHOT</version> <name>dockerfile-maven-plugin</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> <exclusions> <exclusion> <groupId>org.junit.vintage</groupId> <artifactId>junit-vintage-engine</artifactId> </exclusion> </exclusions> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> <!-- dockerfile-maven-plugin --> <plugin> <groupId>com.spotify</groupId> <artifactId>dockerfile-maven-plugin</artifactId> <version>1.3.6</version> <executions> <execution> <id>default</id> <goals> <goal>build</goal> </goals> </execution> </executions> <configuration> <repository>com.naylor/${project.artifactId}</repository> <tag>${project.version}</tag> <buildArgs> <JAR_FILE>${project.build.finalName}.jar</JAR_FILE> </buildArgs> </configuration> </plugin> </plugins> </build> </project>
增加Dockerfile檔案
在專案根目錄(和pom檔案在同一級)新建一個Dokerfile檔案,檔案內容如下:
FROM java:8 EXPOSE 8080 ARG JAR_FILE ADD target/${JAR_FILE} /app.jar ENTRYPOINT ["java","-jar","/app.jar"]
使用Maven打包應用
首先清理一下maven工程,在ideal的Maven面版中點選Lifecycle-clean或者使用命令列執行mvn clean。
然後,使用maven構建app,在ideal的Maven面版中點選Liftcycle-package或者使用命令列執行 mvn package
再然後在命令列工具中執行docker image ls ,如果不出意外,可以看到一個repository為com.naylor/dockerfile-maven-plugin的docker映象。
執行應用映象
在命令列工具中執行如下命令執行容器:
docker run -d -p 8081:8080 ImageId
- ImageId為上一步生成的映象的id,每次生成的映象id都不一樣
- 此命令作用為基於ImageId構建一個容器,將宿主機的8081埠對映到容器的8080埠
在宿主機瀏覽器中訪問「http://127.0.0.1:8081/hello」可以得到Hello,World的響應。
四、分析mvn package 命令的控制檯輸出
通過mvn package的控制檯輸出,我們可以清晰的觀察到整個流程的執行步驟,完整的輸出如下:
/Library/Java/JavaVirtualMachines/jdk1.8.0_231.jdk/Contents/Home/bin/java -Dmaven.multiModuleProjectDirectory=/Users/chenhd/code/DebrisApp_Springboot/debris-app "-Dmaven.home=/Applications/IntelliJ IDEA 2.app/Contents/plugins/maven/lib/maven3" "-Dclassworlds.conf=/Applications/IntelliJ IDEA 2.app/Contents/plugins/maven/lib/maven3/bin/m2.conf" "-Dmaven.ext.class.path=/Applications/IntelliJ IDEA 2.app/Contents/plugins/maven/lib/maven-event-listener.jar" "-javaagent:/Applications/IntelliJ IDEA 2.app/Contents/lib/idea_rt.jar=58649:/Applications/IntelliJ IDEA 2.app/Contents/bin" -Dfile.encoding=UTF-8 -classpath "/Applications/IntelliJ IDEA 2.app/Contents/plugins/maven/lib/maven3/boot/plexus-classworlds-2.6.0.jar" org.codehaus.classworlds.Launcher -Didea.version2020.1 package [INFO] Scanning for projects... [INFO] [INFO] -----------------< com.naylor:dockerfile-maven-plugin >----------------- [INFO] Building dockerfile-maven-plugin 0.0.1-SNAPSHOT [INFO] --------------------------------[ jar ]--------------------------------- [INFO] [INFO] --- maven-resources-plugin:3.1.0:resources (default-resources) @ dockerfile-maven-plugin --- [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) @ dockerfile-maven-plugin --- [INFO] Nothing to compile - all classes are up to date [INFO] [INFO] --- maven-resources-plugin:3.1.0:testResources (default-testResources) @ dockerfile-maven-plugin --- [INFO] Using 'UTF-8' encoding to copy filtered resources. [INFO] skip non existing resourceDirectory /Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin/src/test/resources [INFO] [INFO] --- maven-compiler-plugin:3.8.1:testCompile (default-testCompile) @ dockerfile-maven-plugin --- [INFO] Nothing to compile - all classes are up to date [INFO] [INFO] --- maven-surefire-plugin:2.22.2:test (default-test) @ dockerfile-maven-plugin --- [INFO] [INFO] ------------------------------------------------------- [INFO] T E S T S [INFO] ------------------------------------------------------- [INFO] Running com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests 13:49:50.713 [main] DEBUG org.springframework.test.context.BootstrapUtils - Instantiating CacheAwareContextLoaderDelegate from class [org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate] 13:49:50.735 [main] DEBUG org.springframework.test.context.BootstrapUtils - Instantiating BootstrapContext using constructor [public org.springframework.test.context.support.DefaultBootstrapContext(java.lang.Class,org.springframework.test.context.CacheAwareContextLoaderDelegate)] 13:49:50.762 [main] DEBUG org.springframework.test.context.BootstrapUtils - Instantiating TestContextBootstrapper for test class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests] from class [org.springframework.boot.test.context.SpringBootTestContextBootstrapper] 13:49:50.781 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Neither @ContextConfiguration nor @ContextHierarchy found for test class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests],using SpringBootContextLoader 13:49:50.785 [main] DEBUG org.springframework.test.context.support.AbstractContextLoader - Did not detect default resource location for test class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests]: class path resource [com/naylor/dockerfilemavenplugin/DockerfileMavenPluginApplicationTests-context.xml] does not exist 13:49:50.785 [main] DEBUG org.springframework.test.context.support.AbstractContextLoader - Did not detect default resource location for test class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests]: class path resource [com/naylor/dockerfilemavenplugin/DockerfileMavenPluginApplicationTestsContext.groovy] does not exist 13:49:50.785 [main] INFO org.springframework.test.context.support.AbstractContextLoader - Could not detect default resource locations for test class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests]: no resource found for suffixes {-context.xml,Context.groovy}. 13:49:50.786 [main] INFO org.springframework.test.context.support.AnnotationConfigContextLoaderUtils - Could not detect default configuration classes for test class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests]: DockerfileMavenPluginApplicationTests does not declare any static,non-private,non-final,nested classes annotated with @Configuration. 13:49:50.826 [main] DEBUG org.springframework.test.context.support.ActiveProfilesUtils - Could not find an 'annotation declaring class' for annotation type [org.springframework.test.context.ActiveProfiles] and class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests] 13:49:50.926 [main] DEBUG org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider - Identified candidate component class: file [/Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin/target/classes/com/naylor/dockerfilemavenplugin/DockerfileMavenPluginApplication.class] 13:49:50.932 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Found @SpringBootConfiguration com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplication for test class com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests 13:49:51.069 [main] DEBUG org.springframework.boot.test.context.SpringBootTestContextBootstrapper - @TestExecutionListeners is not present for class [com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests]: using defaults. 13:49:51.070 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Loaded default TestExecutionListener class names from location [META-INF/spring.factories]: [org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener,org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener,org.springframework.boot.test.autoconfigure.restdocs.RestDocsTestExecutionListener,org.springframework.boot.test.autoconfigure.web.client.MockRestServiceServerResetTestExecutionListener,org.springframework.boot.test.autoconfigure.web.servlet.MockMvcPrintOnlyOnFailureTestExecutionListener,org.springframework.boot.test.autoconfigure.web.servlet.WebDriverTestExecutionListener,org.springframework.boot.test.autoconfigure.webservices.client.MockWebServiceServerTestExecutionListener,org.springframework.test.context.web.ServletTestExecutionListener,org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener,org.springframework.test.context.support.DependencyInjectionTestExecutionListener,org.springframework.test.context.support.DirtiesContextTestExecutionListener,org.springframework.test.context.transaction.TransactionalTestExecutionListener,org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener,org.springframework.test.context.event.EventPublishingTestExecutionListener] 13:49:51.096 [main] DEBUG org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Skipping candidate TestExecutionListener [org.springframework.test.context.transaction.TransactionalTestExecutionListener] due to a missing dependency. Specify custom listener classes or make the default listener classes and their required dependencies available. Offending class: [org/springframework/transaction/interceptor/TransactionAttributeSource] 13:49:51.098 [main] DEBUG org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Skipping candidate TestExecutionListener [org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener] due to a missing dependency. Specify custom listener classes or make the default listener classes and their required dependencies available. Offending class: [org/springframework/transaction/interceptor/TransactionAttribute] 13:49:51.098 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Using TestExecutionListeners: [org.springframework.test.context.web.ServletTestExecutionListener@5acf93bb,org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener@7e7be63f,org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener@6cd28fa7,org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener@614ca7df,org.springframework.test.context.support.DirtiesContextTestExecutionListener@4738a206,org.springframework.test.context.event.EventPublishingTestExecutionListener@66d3eec0,org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener@1e04fa0a,org.springframework.boot.test.autoconfigure.restdocs.RestDocsTestExecutionListener@1af2d44a,org.springframework.boot.test.autoconfigure.web.client.MockRestServiceServerResetTestExecutionListener@18d87d80,org.springframework.boot.test.autoconfigure.web.servlet.MockMvcPrintOnlyOnFailureTestExecutionListener@618425b5,org.springframework.boot.test.autoconfigure.web.servlet.WebDriverTestExecutionListener@58695725,org.springframework.boot.test.autoconfigure.webservices.client.MockWebServiceServerTestExecutionListener@543588e6] 13:49:51.114 [main] DEBUG org.springframework.test.context.support.AbstractDirtiesContextTestExecutionListener - Before test class: context [DefaultTestContext@209da20d testClass = DockerfileMavenPluginApplicationTests,testInstance = [null],testMethod = [null],testException = [null],mergedContextConfiguration = [WebMergedContextConfiguration@e15b7e8 testClass = DockerfileMavenPluginApplicationTests,locations = '{}',classes = '{class com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplication}',contextInitializerClasses = '[]',activeProfiles = '{}',propertySourceLocations = '{}',propertySourceProperties = '{org.springframework.boot.test.context.SpringBootTestContextBootstrapper=true}',contextCustomizers = set[org.springframework.boot.test.context.filter.ExcludeFilterContextCustomizer@27ae2fd0,org.springframework.boot.test.json.DuplicateJsonObjectContextCustomizerFactory$DuplicateJsonObjectContextCustomizer@4278a03f,org.springframework.boot.test.mock.mockito.MockitoContextCustomizer@0,org.springframework.boot.test.web.client.TestRestTemplateContextCustomizer@2bbf180e,org.springframework.boot.test.autoconfigure.properties.PropertyMappingContextCustomizer@0,org.springframework.boot.test.autoconfigure.web.servlet.WebDriverContextCustomizerFactory$Customizer@96def03,org.springframework.boot.test.context.SpringBootTestArgs@1],resourceBasePath = 'src/main/webapp',contextLoader = 'org.springframework.boot.test.context.SpringBootContextLoader',parent = [null]],attributes = map['org.springframework.test.context.web.ServletTestExecutionListener.activateListener' -> true]],class annotated with @DirtiesContext [false] with mode [null]. 13:49:51.152 [main] DEBUG org.springframework.test.context.support.TestPropertySourceUtils - Adding inlined properties to environment: {spring.jmx.enabled=false,org.springframework.boot.test.context.SpringBootTestContextBootstrapper=true} . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__,| / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v2.3.4.RELEASE) 2020-10-12 13:49:51.449 INFO 16693 --- [ main] .d.DockerfileMavenPluginApplicationTests : Starting DockerfileMavenPluginApplicationTests on neiyo with PID 16693 (started by chenhd in /Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin) 2020-10-12 13:49:51.451 INFO 16693 --- [ main] .d.DockerfileMavenPluginApplicationTests : No active profile set,falling back to default profiles: default 2020-10-12 13:49:52.458 INFO 16693 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor' 2020-10-12 13:49:52.732 INFO 16693 --- [ main] .d.DockerfileMavenPluginApplicationTests : Started DockerfileMavenPluginApplicationTests in 1.559 seconds (JVM running for 2.86) [INFO] Tests run: 1,Failures: 0,Errors: 0,Skipped: 0,Time elapsed: 2.313 s - in com.naylor.dockerfilemavenplugin.DockerfileMavenPluginApplicationTests 2020-10-12 13:49:53.042 INFO 16693 --- [extShutdownHook] o.s.s.concurrent.ThreadPoolTaskExecutor : Shutting down ExecutorService 'applicationTaskExecutor' [INFO] [INFO] Results: [INFO] [INFO] Tests run: 1,Skipped: 0 [INFO] [INFO] [INFO] --- maven-jar-plugin:3.2.0:jar (default-jar) @ dockerfile-maven-plugin --- [INFO] Building jar: /Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin/target/dockerfile-maven-plugin-0.0.1-SNAPSHOT.jar [INFO] [INFO] --- spring-boot-maven-plugin:2.3.4.RELEASE:repackage (repackage) @ dockerfile-maven-plugin --- [INFO] Replacing main artifact with repackaged archive [INFO] [INFO] --- dockerfile-maven-plugin:1.3.6:build (default) @ dockerfile-maven-plugin --- [INFO] Building Docker context /Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin [INFO] [INFO] Image will be built as com.naylor/dockerfile-maven-plugin:0.0.1-SNAPSHOT [INFO] [INFO] Step 1/5 : FROM java:8 [INFO] [INFO] Pulling from library/java [INFO] Digest: sha256:c1ff613e8ba25833d2e1940da0940c3824f03f802c449f3d1815a66b7f8c0e9d [INFO] Status: Image is up to date for java:8 [INFO] ---> d23bdf5b1b1b [INFO] Step 2/5 : EXPOSE 8080 [INFO] [INFO] ---> Using cache [INFO] ---> 75767466e0be [INFO] Step 3/5 : ARG JAR_FILE [INFO] [INFO] ---> Using cache [INFO] ---> 2ecdd1234dc2 [INFO] Step 4/5 : ADD target/${JAR_FILE} /app.jar [INFO] [INFO] ---> 6169104a5073 [INFO] Step 5/5 : ENTRYPOINT ["java","/app.jar"] [INFO] [INFO] ---> Running in 23596d4612b6 [INFO] Removing intermediate container 23596d4612b6 [INFO] ---> 993715a0e72a [INFO] Successfully built 993715a0e72a [INFO] Successfully tagged com.naylor/dockerfile-maven-plugin:0.0.1-SNAPSHOT [INFO] [INFO] Detected build of image with id 993715a0e72a [INFO] Building jar: /Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin/target/dockerfile-maven-plugin-0.0.1-SNAPSHOT-docker-info.jar [INFO] Successfully built com.naylor/dockerfile-maven-plugin:0.0.1-SNAPSHOT [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 16.597 s [INFO] Finished at: 2020-10-12T13:50:03+08:00 [INFO] ------------------------------------------------------------------------
重點分析一下此行後面的日誌:
--- dockerfile-maven-plugin:1.3.6:build (default) @ dockerfile-maven-plugin ---
Building Docker context /Users/chenhd/code/DebrisApp_Springboot/debris-app/dockerfile-maven-plugin
執行dockerfile-maven-plugin專案的docker上下文的構建
Image will be built as com.naylor/dockerfile-maven-plugin:0.0.1-SNAPSHOT
構建完成之後映象的名稱為:com.naylor/dockerfile-maven-plugin:0.0.1-SNAPSHOT
Step 1/5 : FROM java:8
dockerfile中一共定義了5步來執行構建,第一步是拉取java8的映象,如果本地沒有會從遠端倉庫中搜索並下載下來
Successfully tagged com.naylor/dockerfile-maven-plugin:0.0.1-SNAPSHOT
成功打包了映象
引用
1:官網:https://github.com/spotify/dockerfile-maven
2:dockerfile參考:https://docs.docker.com/engine/reference/builder/
到此這篇關於dockerfile-maven-plugin極簡教程的文章就介紹到這了,更多相關dockerfile-maven-plugin內容請搜尋我們以前的文章或繼續瀏覽下面的相關文章希望大家以後多多支援我們!