环境
- virtual box 6.1
- centos 7.8
- docker 19.03
- kubernetes 1.20.2
- Spring Boot 2.5.0-M1
目标
创建一个 Spring Boot 项目，可以返回主机名，然后打包成镜像，并推送到远程仓库。
创建 Spring Boot 项目
pom.xml
其中 image.name 表示生成的镜像名称，需要替换成自己的用户名。
<?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>2.5.0-M1</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<groupId>jiangbo.spring.docker</groupId>
<artifactId>spring-docker</artifactId>
<version>1.0.0</version>
<name>spring-boot-docker</name>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<image>
<name>jiangbo920827/${project.artifactId}</name>
</image>
</configuration>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
</pluginRepository>
</pluginRepositories>
</project>
主机名
package jiangbo.spring.docker;
import java.net.InetAddress;
import java.net.UnknownHostException;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@SpringBootApplication
@RestController
public class SpringDockerApplication {
private static String hostname;
public static void main(String[] args) throws UnknownHostException {
hostname = InetAddress.getLocalHost().getHostName();
SpringApplication.run(SpringDockerApplication.class, args);
}
@GetMapping("/hostname")
public String hello() {
return hostname;
}
}
打包镜像
本地 Docker 环境
PS D:workspacestsspring-docker> docker version -f "{{.Client.Version}}"
20.10.2
如果没有安装 Docker，可以参考：Docker：在 wsl2 上安装 docker
安装完成后，最好安装一个桌面使用的 Docker Desktop。
构建镜像
PS D:workspacestsspring-docker> mvn spring-boot:build-image
[INFO] Scanning for projects...
[INFO]
[INFO] ----------------< jiangbo.spring.docker:spring-docker >-----------------
[INFO] Building spring-boot-docker 1.0.0
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] >>> spring-boot-maven-plugin:2.5.0-M1:build-image (default-cli) > package @ spring-docker >>>
[INFO]
[INFO] --- maven-resources-plugin:3.2.0:resources (default-resources) @ spring-docker ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Using 'UTF-8' encoding to copy filtered properties files.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ spring-docker ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-compiler-plugin:3.8.1:testCompile (default-testCompile) @ spring-docker ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-surefire-plugin:2.22.2:test (default-test) @ spring-docker ---
[INFO]
[INFO] --- maven-jar-plugin:3.2.0:jar (default-jar) @ spring-docker ---
[INFO]
[INFO] --- spring-boot-maven-plugin:2.5.0-M1:repackage (repackage) @ spring-docker ---
[INFO] Replacing main artifact with repackaged archive
[INFO]
[INFO] <<< spring-boot-maven-plugin:2.5.0-M1:build-image (default-cli) < package @ spring-docker <<<
[INFO]
[INFO]
[INFO] --- spring-boot-maven-plugin:2.5.0-M1:build-image (default-cli) @ spring-boot-docker ---
[INFO] Building image 'docker.io/jiangbo920827/spring-docker:1.0.0'
[INFO]
[INFO] > Pulling builder image 'docker.io/paketobuildpacks/builder:base' 100%
[INFO] > Pulled builder image 'paketobuildpacks/builder@sha256:c9141bd56f3e837a9d618c9e6748b8d5ab0783728a4924bbca41c7e8fb21fca5'
[INFO] > Pulling run image 'docker.io/paketobuildpacks/run:base-cnb' 100%
[INFO] > Pulled run image 'paketobuildpacks/run@sha256:79bd9986ae32d62e8339e602b61ca6288df8434d5e2972bed5d7644d6b8ed0d0'
[INFO] > Executing lifecycle version v0.10.1
[INFO] > Using build cache volume 'pack-cache-7107a48ebc7b.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 6.0.0
[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] Previous image with name "docker.io/jiangbo920827/spring-docker:1.0.0" not found
[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: Contributing to layer
[INFO] [creator] Creating /layers/paketo-buildpacks_ca-certificates/helper/exec.d/ca-certificates-helper
[INFO] [creator] Writing profile.d/helper
[INFO] [creator]
[INFO] [creator] Paketo BellSoft Liberica Buildpack 6.0.0
[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: Contributing to layer
[INFO] [creator] Downloading from https://github.com/bell-sw/Liberica/releases/download/8u275+1/bellsoft-jre8u275+1-linux-amd64.tar.gz
[INFO] [creator] Verifying checksum
[INFO] [creator] Expanding to /layers/paketo-buildpacks_bellsoft-liberica/jre
[INFO] [creator] Adding 138 container CA certificates to JVM truststore
[INFO] [creator] Writing env.launch/BPI_APPLICATION_PATH.default
[INFO] [creator] Writing env.launch/BPI_JVM_CACERTS.default
[INFO] [creator] Writing env.launch/BPI_JVM_CLASS_COUNT.default
[INFO] [creator] Writing env.launch/BPI_JVM_EXT_DIR.default
[INFO] [creator] Writing env.launch/BPI_JVM_SECURITY_PROVIDERS.default
[INFO] [creator] Writing env.launch/JAVA_HOME.default
[INFO] [creator] Writing env.launch/MALLOC_ARENA_MAX.default
[INFO] [creator] Launch Helper: Contributing to layer
[INFO] [creator] Creating /layers/paketo-buildpacks_bellsoft-liberica/helper/exec.d/active-processor-count
[INFO] [creator] Creating /layers/paketo-buildpacks_bellsoft-liberica/helper/exec.d/java-opts
[INFO] [creator] Creating /layers/paketo-buildpacks_bellsoft-liberica/helper/exec.d/link-local-dns
[INFO] [creator] Creating /layers/paketo-buildpacks_bellsoft-liberica/helper/exec.d/memory-calculator
[INFO] [creator] Creating /layers/paketo-buildpacks_bellsoft-liberica/helper/exec.d/openssl-certificate-loader
[INFO] [creator] Creating /layers/paketo-buildpacks_bellsoft-liberica/helper/exec.d/security-providers-configurer
[INFO] [creator] Creating /layers/paketo-buildpacks_bellsoft-liberica/helper/exec.d/security-providers-classpath-8
[INFO] [creator] Writing profile.d/helper
[INFO] [creator] JVMKill Agent 1.16.0: Contributing to layer
[INFO] [creator] Downloading from https://github.com/cloudfoundry/jvmkill/releases/download/v1.16.0.RELEASE/jvmkill-1.16.0-RELEASE.so
[INFO] [creator] Verifying checksum
[INFO] [creator] Copying to /layers/paketo-buildpacks_bellsoft-liberica/jvmkill
[INFO] [creator] Writing env.launch/JAVA_TOOL_OPTIONS.append
[INFO] [creator] Writing env.launch/JAVA_TOOL_OPTIONS.delim
[INFO] [creator] Java Security Properties: Contributing to layer
[INFO] [creator] Writing env.launch/JAVA_SECURITY_PROPERTIES.default
[INFO] [creator] Writing env.launch/JAVA_TOOL_OPTIONS.append
[INFO] [creator] Writing env.launch/JAVA_TOOL_OPTIONS.delim
[INFO] [creator]
[INFO] [creator] Paketo Executable JAR Buildpack 3.1.3
[INFO] [creator] https://github.com/paketo-buildpacks/executable-jar
[INFO] [creator] Writing env.launch/CLASSPATH.delim
[INFO] [creator] Writing env.launch/CLASSPATH.prepend
[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: Contributing to layer
[INFO] [creator] Creating /layers/paketo-buildpacks_spring-boot/helper/exec.d/spring-cloud-bindings
[INFO] [creator] Writing profile.d/helper
[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: Contributing to layer
[INFO] [creator] Downloading from https://repo.spring.io/release/org/springframework/cloud/spring-cloud-bindings/1.7.0/spring-cloud-bindings-1.7.0.jar
[INFO] [creator] Verifying checksum
[INFO] [creator] Copying to /layers/paketo-buildpacks_spring-boot/spring-cloud-bindings
[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] Adding layer 'paketo-buildpacks/ca-certificates:helper'
[INFO] [creator] Adding layer 'paketo-buildpacks/bellsoft-liberica:helper'
[INFO] [creator] Adding layer 'paketo-buildpacks/bellsoft-liberica:java-security-properties'
[INFO] [creator] Adding layer 'paketo-buildpacks/bellsoft-liberica:jre'
[INFO] [creator] Adding layer 'paketo-buildpacks/bellsoft-liberica:jvmkill'
[INFO] [creator] Adding layer 'paketo-buildpacks/executable-jar:class-path'
[INFO] [creator] Adding layer 'paketo-buildpacks/spring-boot:helper'
[INFO] [creator] Adding layer 'paketo-buildpacks/spring-boot:spring-cloud-bindings'
[INFO] [creator] Adding layer 'paketo-buildpacks/spring-boot:web-application-type'
[INFO] [creator] Adding 5/5 app layer(s)
[INFO] [creator] Adding layer 'launcher'
[INFO] [creator] Adding layer 'config'
[INFO] [creator] Adding 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 (ba6729253f7d):
[INFO] [creator] docker.io/jiangbo920827/spring-docker:1.0.0
[INFO]
[INFO] Successfully built image 'docker.io/jiangbo920827/spring-docker:1.0.0'
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 49:10 min
[INFO] Finished at: 2021-01-23T22:58:53+08:00
[INFO] ------------------------------------------------------------------------
使用 Spring Boot 自带的方式是最简单构建镜像的方式，但是由于网络原因，很可能会在构建的过程中，下载文件失败。
可以参考：【Docker】Spring Boot 和 Docker，里面介绍了生成镜像的方式和生成镜像的大小。
查看镜像
PS C:UsersJiangBo> docker image ls jiangbo920827/spring-docker
REPOSITORY TAG IMAGE ID CREATED SIZE
jiangbo920827/spring-docker 1.0.0 ba6729253f7d 41 years ago 244MB
上传到远程仓库
PS C:UsersJiangBo> docker login -u jiangbo920827
PS C:UsersJiangBo> docker push jiangbo920827/spring-docker:1.0.0
除了使用命令，可以直接使用界面推送：
在远程仓库查看
总结
介绍了编写 Spring Boot 返回主机名，并将程序打包成镜像上传到 Docker 远程仓库。