为了方便为SpringBoot应用构建Docker镜像，我们经常会使用Maven插件来打包镜像。之前一直使用的是第三方插件，有
spotify和fabric8出品的两种docker-maven-plugin。最近SpringBoot 2.4.0发布了，官方插件也增加了对Docker的支持，体验了一把发现也很好用，推荐给大家！
第三方插件使用
我们先了解下第三方插件的使用，方便和官方插件做对比，
fabric8插件使用具体可以参考《还在手动部署SpringBoot应用？试试这个自动化插件！》。
值得注意的是，在我们使用插件时，需要自己定义镜像构建过程，比如在
pom.xml中使用如下配置，<images>标签下的配置为镜像构建过程的配置；
-
<build>
-
<plugins>
-
<plugin>
-
<groupId>io.fabric8</groupId>
-
<artifactId>docker-maven-plugin</artifactId>
-
<version>
0.33
.0</version>
-
<configuration>
-
<!-- Docker 远程管理地址-->
-
<dockerHost>http:
//192.168.3.101:2375</dockerHost>
-
<!-- Docker 推送镜像仓库地址-->
-
<pushRegistry>http:
//192.168.3.101:5000</pushRegistry>
-
<images>
-
<image>
-
<!--由于推送到私有镜像仓库，镜像名需要添加仓库地址-->
-
<name>
192.168
.3
.101:
5000/mall-tiny/${project.name}:${project.version}</name>
-
<!--定义镜像构建行为-->
-
<build>
-
<!--定义基础镜像-->
-
<from>java:
8</from>
-
<args>
-
<JAR_FILE>${project.build.finalName}.jar</JAR_FILE>
-
</args>
-
<!--定义哪些文件拷贝到容器中-->
-
<assembly>
-
<!--定义拷贝到容器的目录-->
-
<targetDir>/</targetDir>
-
<!--只拷贝生成的jar包-->
-
<descriptorRef>artifact</descriptorRef>
-
</assembly>
-
<!--定义容器启动命令-->
-
<entryPoint>[
"java",
"-jar",
"/${project.build.finalName}.jar"]</entryPoint>
-
<!--定义维护者-->
-
<maintainer>macrozheng</maintainer>
-
</build>
-
</image>
-
</images>
-
</configuration>
-
</plugin>
-
</plugins>
-
</build>
或者先在Dockerfile文件中定义好镜像构建过程；
-
# 该镜像需要依赖的基础镜像
-
FROM java:
8
-
# 将当前maven目录生成的文件复制到docker容器的/目录下
-
COPY maven /
-
# 声明服务运行在
8080端口
-
EXPOSE
8080
-
# 指定docker容器启动时运行jar包
-
ENTRYPOINT [
"java",
"-jar",
"/mall-tiny-fabric-0.0.1-SNAPSHOT.jar"]
-
# 指定维护者的名字
-
MAINTAINER macrozheng
然后在插件中引用Dockerfile文件，用于构建镜像；
-
<build>
-
<dockerFileDir>${project.basedir}</dockerFileDir>
-
</build>
其实对于SpringBoot应用来说，如何从应用Jar包构建Docker镜像，做法基本是差不多的，为什么非要自己定义镜像的构建过程呢？
官方插件使用
SpringBoot官方插件解决了上面的问题，无需自己编写Docker镜像构建过程，直接自动构建，是不是很方便！接下来我们来体验下它的强大之处！
由于我们需要把镜像推送到镜像仓库，首先我们安装好私有镜像仓库
Registry和可视化镜像管理工具docker-registry-ui，具体可以参考《还在手动部署SpringBoot应用？试试这个自动化插件！》；
-
[root@linux-local ~]# docker ps
-
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
-
9ffec08467ac joxit/docker-registry-ui:static
"/bin/sh -c entrypoi…"
2 hours ago Up
2 hours
0.0
.0
.0:
8280->
80/tcp registry-ui
-
a809535ee2a2 registry:
2
"/entrypoint.sh /etc…"
3 months ago Up
7 hours
0.0
.0
.0:
5000->
5000/tcp registry2
然后我们需要把应用的版本升级到SpringBoot 2.4.0，之前的版本Docker支持没有这个完善；
-
<parent>
-
<groupId>org.springframework.boot</groupId>
-
<artifactId>spring-boot-starter-parent</artifactId>
-
<version>
2.4
.0</version>
-
<relativePath/> <!-- lookup parent from repository -->
-
</parent>
然后修改
pom.xml文件，对官方Maven插件进行配置，主要是对Docker相关功能进行配置；
-
<plugin>
-
<groupId>org.springframework.boot</groupId>
-
<artifactId>spring-boot-maven-plugin</artifactId>
-
<configuration>
-
<image>
-
<!--配置镜像名称-->
-
<name>
192.168
.3
.101:
5000/mall-tiny/${project.name}:${project.version}</name>
-
<!--镜像打包完成后自动推送到镜像仓库-->
-
<publish>
true</publish>
-
</image>
-
<docker>
-
<!--Docker远程管理地址-->
-
<host>http:
//192.168.3.101:2375</host>
-
<!--不使用TLS访问-->
-
<tlsVerify>
false</tlsVerify>
-
<!--Docker推送镜像仓库配置-->
-
<publishRegistry>
-
<!--推送镜像仓库用户名-->
-
<username>test</username>
-
<!--推送镜像仓库密码-->
-
<password>test</password>
-
<!--推送镜像仓库地址-->
-
<url>http:
//192.168.3.101:5000</url>
-
</publishRegistry>
-
</docker>
-
</configuration>
-
</plugin>
如果你使用的是IDEA的话，直接双击SpringBoot插件的
build-image命令即可一键打包并推送到镜像仓库；
也可以在命令行使用如下Maven命令来打包构建镜像；
mvn spring-boot:build-image
镜像构建过程中会输出如下信息，由于很多依赖会从Github上下载，网络不好的情况下会下载失败，多试几次就好：
-
[INFO] > Pulling builder image
'docker.io/paketobuildpacks/builder:base'
100%
-
[INFO] > Pulled builder image
'paketobuildpacks/builder@sha256:9d377230ba8ee74d8619178fd318b1b87a7da1a88bdb198afd14dd7de9e8ea6a'
-
[INFO] > Pulling run image
'docker.io/paketobuildpacks/run:base-cnb'
100%
-
[INFO] > Pulled run image
'paketobuildpacks/run@sha256:33d37fc9ba16e220f071805eaeed881a508ceee5c8909db5710aaed7e97e4fc2'
-
[INFO] > Executing lifecycle version v0
.9
.3
-
[INFO] > Using build cache volume
'pack-cache-5641f846df6.build'
-
[INFO]
-
[INFO] > Running creator
-
[INFO] [creator] ===> DETECTING
-
[INFO] [creator]
5 of
18 buildpacks participating
-
[INFO] [creator] paketo-buildpacks/ca-certificates
1.0
.1
-
[INFO] [creator] paketo-buildpacks/bellsoft-liberica
5.2
.1
-
[INFO] [creator] paketo-buildpacks/executable-jar
3.1
.3
-
[INFO] [creator] paketo-buildpacks/dist-zip
2.2
.2
-
[INFO] [creator] paketo-buildpacks/spring-boot
3.5
.0
-
[INFO] [creator] ===> ANALYZING
-
[INFO] [creator] Restoring metadata
for
"paketo-buildpacks/ca-certificates:helper" from app image
-
[INFO] [creator] Restoring metadata
for
"paketo-buildpacks/bellsoft-liberica:helper" from app image
-
[INFO] [creator] Restoring metadata
for
"paketo-buildpacks/bellsoft-liberica:java-security-properties" from app image
-
[INFO] [creator] Restoring metadata
for
"paketo-buildpacks/bellsoft-liberica:jre" from app image
-
[INFO] [creator] Restoring metadata
for
"paketo-buildpacks/bellsoft-liberica:jvmkill" from app image
-
[INFO] [creator] Restoring metadata
for
"paketo-buildpacks/executable-jar:class-path" from app image
-
[INFO] [creator] Restoring metadata
for
"paketo-buildpacks/spring-boot:helper" from app image
-
[INFO] [creator] Restoring metadata
for
"paketo-buildpacks/spring-boot:spring-cloud-bindings" from app image
-
[INFO] [creator] Restoring metadata
for
"paketo-buildpacks/spring-boot:web-application-type" from app image
-
[INFO] [creator] ===> RESTORING
-
[INFO] [creator] ===> BUILDING
-
[INFO] [creator]
-
[INFO] [creator] Paketo CA Certificates Buildpack
1.0
.1
-
[INFO] [creator] https:
//github.com/paketo-buildpacks/ca-certificates
-
[INFO] [creator] Launch Helper: Reusing cached layer
-
[INFO] [creator]
-
[INFO] [creator] Paketo BellSoft Liberica Buildpack
5.2
.1
-
[INFO] [creator] https:
//github.com/paketo-buildpacks/bellsoft-liberica
-
[INFO] [creator] Build Configuration:
-
[INFO] [creator] $BP_JVM_VERSION
8.* the Java version
-
[INFO] [creator] Launch Configuration:
-
[INFO] [creator] $BPL_JVM_HEAD_ROOM
0 the headroom in memory calculation
-
[INFO] [creator] $BPL_JVM_LOADED_CLASS_COUNT
35% of classes the number of loaded classes in memory calculation
-
[INFO] [creator] $BPL_JVM_THREAD_COUNT
250 the number of threads in memory calculation
-
[INFO] [creator] $JAVA_TOOL_OPTIONS the JVM launch flags
-
[INFO] [creator] BellSoft Liberica JRE
8.0
.275: Reusing cached layer
-
[INFO] [creator] Launch Helper: Reusing cached layer
-
[INFO] [creator] JVMKill Agent
1.16
.0: Reusing cached layer
-
[INFO] [creator] Java Security Properties: Reusing cached layer
-
[INFO] [creator]
-
[INFO] [creator] Paketo Executable JAR Buildpack
3.1
.3
-
[INFO] [creator] https:
//github.com/paketo-buildpacks/executable-jar
-
[INFO] [creator] Process types:
-
[INFO] [creator] executable-jar: java org.springframework.boot.loader.JarLauncher
-
[INFO] [creator] task: java org.springframework.boot.loader.JarLauncher
-
[INFO] [creator] web: java org.springframework.boot.loader.JarLauncher
-
[INFO] [creator]
-
[INFO] [creator] Paketo Spring Boot Buildpack
3.5
.0
-
[INFO] [creator] https:
//github.com/paketo-buildpacks/spring-boot
-
[INFO] [creator] Creating slices from layers index
-
[INFO] [creator] dependencies
-
[INFO] [creator] spring-boot-loader
-
[INFO] [creator] snapshot-dependencies
-
[INFO] [creator] application
-
[INFO] [creator] Launch Helper: Reusing cached layer
-
[INFO] [creator] Web Application Type: Contributing to layer
-
[INFO] [creator] Servlet web application detected
-
[INFO] [creator] Writing env.launch/BPL_JVM_THREAD_COUNT.
default
-
[INFO] [creator] Spring Cloud Bindings
1.7
.0: Reusing cached layer
-
[INFO] [creator]
4 application slices
-
[INFO] [creator] Image labels:
-
[INFO] [creator] org.opencontainers.image.title
-
[INFO] [creator] org.opencontainers.image.version
-
[INFO] [creator] org.springframework.boot.spring-configuration-metadata.json
-
[INFO] [creator] org.springframework.boot.version
-
[INFO] [creator] ===> EXPORTING
-
[INFO] [creator] Reusing layer
'paketo-buildpacks/ca-certificates:helper'
-
[INFO] [creator] Reusing layer
'paketo-buildpacks/bellsoft-liberica:helper'
-
[INFO] [creator] Reusing layer
'paketo-buildpacks/bellsoft-liberica:java-security-properties'
-
[INFO] [creator] Reusing layer
'paketo-buildpacks/bellsoft-liberica:jre'
-
[INFO] [creator] Reusing layer
'paketo-buildpacks/bellsoft-liberica:jvmkill'
-
[INFO] [creator] Reusing layer
'paketo-buildpacks/executable-jar:class-path'
-
[INFO] [creator] Reusing layer
'paketo-buildpacks/spring-boot:helper'
-
[INFO] [creator] Reusing layer
'paketo-buildpacks/spring-boot:spring-cloud-bindings'
-
[INFO] [creator] Reusing layer
'paketo-buildpacks/spring-boot:web-application-type'
-
[INFO] [creator] Reusing
4/
5 app layer(s)
-
[INFO] [creator] Adding
1/
5 app layer(s)
-
[INFO] [creator] Reusing layer
'launcher'
-
[INFO] [creator] Reusing layer
'config'
-
[INFO] [creator] Reusing layer
'process-types'
-
[INFO] [creator] Adding label
'io.buildpacks.lifecycle.metadata'
-
[INFO] [creator] Adding label
'io.buildpacks.build.metadata'
-
[INFO] [creator] Adding label
'io.buildpacks.project.metadata'
-
[INFO] [creator] Adding label
'org.opencontainers.image.title'
-
[INFO] [creator] Adding label
'org.opencontainers.image.version'
-
[INFO] [creator] Adding label
'org.springframework.boot.spring-configuration-metadata.json'
-
[INFO] [creator] Adding label
'org.springframework.boot.version'
-
[INFO] [creator] Setting
default process
type
'web'
-
[INFO] [creator] *** Images (d5e1771dac7b):
-
[INFO] [creator]
192.168
.3
.101:
5000/mall-tiny/mall-tiny-docker-plugin:
0.0
.1-SNAPSHOT
-
[INFO]
-
[INFO] Successfully built image
'192.168.3.101:5000/mall-tiny/mall-tiny-docker-plugin:0.0.1-SNAPSHOT'
-
[INFO]
-
[INFO] > Pushed image
'192.168.3.101:5000/mall-tiny/mall-tiny-docker-plugin:0.0.1-SNAPSHOT'
-
[INFO] ------------------------------------------------------------------------
-
[INFO] BUILD SUCCESS
-
[INFO] ------------------------------------------------------------------------
-
[INFO] Total time:
01:
06 min
-
[INFO] Finished at:
2020
-11
-27T15:
07:
46+
08:
00
-
[INFO] Final Memory:
37M/
359M
-
[INFO] ------------------------------------------------------------------------
镜像构建成功后，可以从镜像仓库查看到我们的镜像：
-
[root@linux-local ~]# docker images
-
REPOSITORY TAG IMAGE ID CREATED SIZE
-
paketobuildpacks/run base-cnb a717358311fc
9 days ago
87.2MB
-
java
8 d23bdf5b1b1b
3 years ago
643MB
-
192.168
.3
.101:
5000/mall-tiny/mall-tiny-docker-plugin
0.0
.1-SNAPSHOT d5e1771dac7b
40 years ago
244MB
-
pack.local/builder/fewqajyqsc latest f15fad05a5ba
40 years ago
558MB
-
pack.local/builder/kirivtcqtu latest f15fad05a5ba
40 years ago
558MB
-
paketobuildpacks/builder base
511452064e06
40 years ago
558MB
我们可以从
Docker Registry UI中查看镜像仓库中的镜像，访问地址：http://192.168.3.101:8280/
接着使用如下命令启动我们的SpringBoot应用：
-
docker run -p
8080:
8080 --name mall-tiny-docker-plugin \
-
--link mysql:db \
-
-v /etc/localtime:/etc/localtime \
-
-v /mydata/app/mall-tiny-docker-plugin/logs:/
var/logs \
-
-d
192.168
.3
.101:
5000/mall-tiny/mall-tiny-docker-plugin:
0.0
.1-SNAPSHOT
启动成功后，可以成功访问到SpringBoot应用的Swagger页面，访问地址：http://192.168.3.101:8080/swagger-ui.html
总结
SpringBoot官方Maven插件避免了编写Docker镜像构建过程，同时充分利用了SpringBoot 2.3以后的Jar分层技术，但对于需要自定义构建镜像的场景造成了一定的麻烦。
参考资料
官方文档：https://docs.spring.io/spring-boot/docs/2.4.0/maven-plugin/reference/htmlsingle/#build-image
项目源码地址
https://github.com/macrozheng/mall-learning/tree/master/mall-tiny-docker-plugin
推荐阅读
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转载：https://blog.csdn.net/zhenghongcs/article/details/110848544
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