【Docker】Spring Boot 和 Docker

参考教程：https://spring.io/guides/gs/spring-boot-docker/

环境

virtual box 6.1
centos 7.8
docker 19.03

编写 Spring Boot 服务

定义 pom.xml

<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>2.2.11.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

    <groupId>jiangbo.spring.docker</groupId>
    <artifactId>spring-docker</artifactId>
    <version>1.0.0</version>

    <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>
            </plugin>
        </plugins>
    </build>
</project>

定义接口

package jiangbo.spring.docker;

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 {

    @GetMapping("/")
    public String home() {

        return "Hello Docker World";
    }

    public static void main(String[] args) {

        SpringApplication.run(SpringDockerApplication.class, args);
    }
}

打包并上传到服务器

[root@master demo1]# ll
total 34604
-rw-r--r--. 1 root root      108 Nov 25 20:25 Dockerfile
-rw-r--r--. 1 root root 17711362 Nov 25 20:25 spring-docker-1.0.0.jar
-rw-r--r--. 1 root root 17711374 Nov 25 21:44 spring-docker-1.0.1.jar
[root@master demo1]# pwd
/root/docker/demo1
[root@master demo1]#

生成镜像

定义 Dockerfile

[root@master demo1]# cat Dockerfile
FROM openjdk:8-jdk-alpine
ARG JAR_FILE=*.jar
COPY ${JAR_FILE} app.jar
ENTRYPOINT ["java","-jar","/app.jar"]

生成 1.0.0 镜像

[root@master demo1]# docker build --build-arg JAR_FILE=spring-docker-1.0.0.jar -t gs-spring-boot-docker:1.0.0 .
Sending build context to Docker daemon  35.43MB
Step 1/4 : FROM openjdk:8-jdk-alpine
 ---> a3562aa0b991
Step 2/4 : ARG JAR_FILE=*.jar
 ---> Running in d6f5be8caaf5
Removing intermediate container d6f5be8caaf5
 ---> 729cc2317b0b
Step 3/4 : COPY ${JAR_FILE} app.jar
 ---> 4bcb5820c7c2
Step 4/4 : ENTRYPOINT ["java","-jar","/app.jar"]
 ---> Running in a0de243efcdc
Removing intermediate container a0de243efcdc
 ---> 2fea2b509a53
Successfully built 2fea2b509a53
Successfully tagged gs-spring-boot-docker:1.0.0
[root@master demo1]# docker image ls
REPOSITORY                       TAG                 IMAGE ID            CREATED             SIZE
gs-spring-boot-docker            1.0.0               2fea2b509a53        13 seconds ago      123MB
springio/gs-spring-boot-docker   latest              b4368075c1fc        16 minutes ago      122MB
ubuntu                           latest              d70eaf7277ea        4 weeks ago         72.9MB
openjdk                          8-jdk-alpine        a3562aa0b991        18 months ago       105MB
[root@master demo1]#

生成 1.0.1 镜像

[root@master demo1]# docker build --build-arg JAR_FILE=spring-docker-1.0.1.jar -t gs-spring-boot-docker:1.0.1 .
Sending build context to Docker daemon  35.43MB
Step 1/4 : FROM openjdk:8-jdk-alpine
 ---> a3562aa0b991
Step 2/4 : ARG JAR_FILE=*.jar
 ---> Using cache
 ---> 528e5285c315
Step 3/4 : COPY ${JAR_FILE} app.jar
 ---> Using cache
 ---> 069384d42672
Step 4/4 : ENTRYPOINT ["java","-jar","/app.jar"]
 ---> Using cache
 ---> df2edec3a41a
Successfully built df2edec3a41a
Successfully tagged gs-spring-boot-docker:1.0.1
[root@master demo1]# docker image ls
REPOSITORY                       TAG                 IMAGE ID            CREATED             SIZE
gs-spring-boot-docker            1.0.1               df2edec3a41a        37 seconds ago      123MB
gs-spring-boot-docker            1.0.0               2fea2b509a53        2 minutes ago       123MB
springio/gs-spring-boot-docker   latest              b4368075c1fc        19 minutes ago      122MB
ubuntu                           latest              d70eaf7277ea        4 weeks ago         72.9MB
openjdk                          8-jdk-alpine        a3562aa0b991        18 months ago       105MB
[root@master demo1]#

镜像的大小

分别导出镜像

[root@master demo1]# docker save gs-spring-boot-docker:1.0.0 -o gs-spring-boot-docker:1.0.0.tar
[root@master demo1]# docker save gs-spring-boot-docker:1.0.1 -o gs-spring-boot-docker:1.0.1.tar
[root@master demo1]# mkdir images
[root@master demo1]# mv gs-spring-boot-docker\:1.0.* images/
[root@master demo1]# tar -zcvf images.tar.gz images/
images/
images/gs-spring-boot-docker:1.0.0.tar
images/gs-spring-boot-docker:1.0.1.tar
[root@master demo1]# ll -h
total 203M
-rw-r--r--. 1 root root  108 Nov 25 20:25 Dockerfile
drwxr-xr-x. 2 root root   84 Nov 25 21:55 images
-rw-r--r--. 1 root root 170M Nov 25 21:55 images.tar.gz
-rw-r--r--. 1 root root  17M Nov 25 20:25 spring-docker-1.0.0.jar
-rw-r--r--. 1 root root  17M Nov 25 21:44 spring-docker-1.0.1.jar

一起导出镜像

[root@master demo1]# docker save gs-spring-boot-docker:1.0.0 gs-spring-boot-docker:1.0.1 | gzip > images2.tar.gz
[root@master demo1]# ll -h
total 303M
-rw-r--r--. 1 root root  108 Nov 25 20:25 Dockerfile
drwxr-xr-x. 2 root root   84 Nov 25 21:55 images
-rw-r--r--. 1 root root 100M Nov 25 21:57 images2.tar.gz
-rw-r--r--. 1 root root 170M Nov 25 21:55 images.tar.gz
-rw-r--r--. 1 root root  17M Nov 25 20:25 spring-docker-1.0.0.jar
-rw-r--r--. 1 root root  17M Nov 25 21:44 spring-docker-1.0.1.jar

镜像的体积明显降低了，如果镜像数和共用的层越多，则减少的体积越明显。因为它们共用了基础的 openjdk 镜像。

分层构建镜像

定义构建文件

FROM openjdk:8-jdk-alpine
RUN addgroup -S spring && adduser -S spring -G spring
USER spring:spring
ARG DEPENDENCY=target/dependency
COPY ${DEPENDENCY}/BOOT-INF/lib /app/lib
COPY ${DEPENDENCY}/META-INF /app/META-INF
COPY ${DEPENDENCY}/BOOT-INF/classes /app
ENTRYPOINT ["java","-cp","app:app/lib/*","jiangbo.spring.docker.SpringDockerApplication"]

使用分层构建

[root@master demo3]# docker build -t gs-spring-boot-docker:1.0.0 .
Sending build context to Docker daemon   35.6MB
Step 1/8 : FROM openjdk:8-jdk-alpine
 ---> a3562aa0b991
Step 2/8 : RUN addgroup -S spring && adduser -S spring -G spring
 ---> Running in 7de3e020b8ee
Removing intermediate container 7de3e020b8ee
 ---> 0b5e90edf7db
Step 3/8 : USER spring:spring
 ---> Running in d6eedeb3d48b
Removing intermediate container d6eedeb3d48b
 ---> c834729e9d31
Step 4/8 : ARG DEPENDENCY=target/dependency
 ---> Running in 05cdec87fea5
Removing intermediate container 05cdec87fea5
 ---> c9623e256de4
Step 5/8 : COPY ${DEPENDENCY}/BOOT-INF/lib /app/lib
 ---> 69a7896fce2f
Step 6/8 : COPY ${DEPENDENCY}/META-INF /app/META-INF
 ---> 34f10a99aaa2
Step 7/8 : COPY ${DEPENDENCY}/BOOT-INF/classes /app
 ---> 5f3ea897413d
Step 8/8 : ENTRYPOINT ["java","-cp","app:app/lib/*","jiangbo.spring.docker.SpringDockerApplication"]
 ---> Running in b0e2c78ebd9b
Removing intermediate container b0e2c78ebd9b
 ---> 87fc89fd35cb
Successfully built 87fc89fd35cb
Successfully tagged gs-spring-boot-docker:1.0.0
[root@master demo3]# docker image ls
REPOSITORY              TAG                 IMAGE ID            CREATED             SIZE
gs-spring-boot-docker   1.0.0               87fc89fd35cb        7 seconds ago       122MB
ubuntu                  latest              d70eaf7277ea        4 weeks ago         72.9MB
openjdk                 8-jdk-alpine        a3562aa0b991        18 months ago       105MB
[root@master demo3]#

启动并验证功能

[root@master demo3]# docker run -d -p8080:8080 gs-spring-boot-docker:1.0.0
39a77196d1f9afe30a3d7ed3b06b4a02a29cd01ada110801d237612a2b0a69bd
[root@master demo3]# curl localhost:8080
Hello Docker World[root@master demo3]#

分层减少体积

构建分层 1.0.1 版本

[root@master demo4]# ll
total 17304
-rw-r--r--. 1 root root      346 Nov 25 22:14 Dockerfile
-rw-r--r--. 1 root root 17711374 Nov 25 21:44 spring-docker-1.0.1.jar
[root@master demo4]# mkdir -p target/dependency && (cd target/dependency; jar -xf ../../*.jar)
[root@master demo4]# docker build -t gs-spring-boot-docker:1.0.1 .
Sending build context to Docker daemon   35.6MB
Step 1/8 : FROM openjdk:8-jdk-alpine
 ---> a3562aa0b991
Step 2/8 : RUN addgroup -S spring && adduser -S spring -G spring
 ---> Using cache
 ---> 0b5e90edf7db
Step 3/8 : USER spring:spring
 ---> Using cache
 ---> c834729e9d31
Step 4/8 : ARG DEPENDENCY=target/dependency
 ---> Using cache
 ---> c9623e256de4
Step 5/8 : COPY ${DEPENDENCY}/BOOT-INF/lib /app/lib
 ---> Using cache
 ---> 69a7896fce2f
Step 6/8 : COPY ${DEPENDENCY}/META-INF /app/META-INF
 ---> f7eeb2f515f6
Step 7/8 : COPY ${DEPENDENCY}/BOOT-INF/classes /app
 ---> 23822d3f9fd8
Step 8/8 : ENTRYPOINT ["java","-cp","app:app/lib/*","jiangbo.spring.docker.SpringDockerApplication"]
 ---> Running in a0001411f73c
Removing intermediate container a0001411f73c
 ---> 6c6f105fb47c
Successfully built 6c6f105fb47c
Successfully tagged gs-spring-boot-docker:1.0.1
[root@master demo4]# docker image ls
REPOSITORY              TAG                 IMAGE ID            CREATED             SIZE
gs-spring-boot-docker   1.0.1               6c6f105fb47c        22 seconds ago      122MB
gs-spring-boot-docker   1.0.0               87fc89fd35cb        4 minutes ago       122MB
ubuntu                  latest              d70eaf7277ea        4 weeks ago         72.9MB
openjdk                 8-jdk-alpine        a3562aa0b991        18 months ago       105MB
[root@master demo4]# docker run -d -p8081:8080 gs-spring-boot-docker:1.0.1
0482f6119e0b72a03b47341c2f5eeac4b89659b5b56a840edfcdb67a2a276fa7
[root@master demo4]# curl localhost:8081
Hello Docker World v1.0.1[root@master demo4]#

比较分层的大小

[root@master demo4]# docker save gs-spring-boot-docker:1.0.0 gs-spring-boot-docker:1.0.1 | gzip > images3.tar.gz
[root@master demo4]# ll -h
total 102M
-rw-r--r--. 1 root root 346 Nov 25 22:14 Dockerfile
-rw-r--r--. 1 root root 85M Nov 25 22:17 images3.tar.gz
-rw-r--r--. 1 root root 17M Nov 25 21:44 spring-docker-1.0.1.jar
drwxr-xr-x. 3 root root  24 Nov 25 22:15 target
[root@master demo4]#

相比较之前的 100M，这次减少了 15M。除了共用的基础 openjdk 镜像，还共用了 spring 的 jar 包层，变化的就只是我们编写的代码层。

spring 2.3 构建镜像

直接构建镜像

可以直接使用 spring-boot:build-image 构建镜像，需要有 Docker 环境，并且会从 github 上下载文件，大概率会失败。

生成分层 jar

Spring Boot 2.3 之后，就可以生成分层 jar 了。

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.4.0</version>
    <relativePath /> <!-- lookup parent from repository -->
</parent>

查看分层

[root@master demo5]#  java -Djarmode=layertools -jar spring-docker-1.0.3.jar list
dependencies
spring-boot-loader
snapshot-dependencies
application
[root@master demo5]#

定义 Dockerfile

[root@master demo5]# cat Dockerfile
FROM openjdk:8-jdk-alpine as builder
WORKDIR application
ARG JAR_FILE=target/*.jar
COPY ${JAR_FILE} application.jar
RUN java -Djarmode=layertools -jar application.jar extract

FROM openjdk:8-jdk-alpine
WORKDIR application
COPY --from=builder application/dependencies/ ./
COPY --from=builder application/snapshot-dependencies/ ./
COPY --from=builder application/application/ ./
ENTRYPOINT ["java", "org.springframework.boot.loader.JarLauncher"]

[root@master demo5]#

整包生成镜像

[root@master demo5]# docker build -t spring-docker:1.0.3 --build-arg JAR_FILE=spring-docker-1.0.3.jar .
Sending build context to Docker daemon  34.68MB
Step 1/11 : FROM openjdk:8-jdk-alpine as builder
 ---> a3562aa0b991
Step 2/11 : WORKDIR application
 ---> Using cache
 ---> a71643e49255
Step 3/11 : ARG JAR_FILE=target/*.jar
 ---> Using cache
 ---> 6662d39ccdf1
Step 4/11 : COPY ${JAR_FILE} application.jar
 ---> Using cache
 ---> 0949a32dea3f
Step 5/11 : RUN java -Djarmode=layertools -jar application.jar extract
 ---> Using cache
 ---> d5bbe3e76dd6
Step 6/11 : FROM openjdk:8-jdk-alpine
 ---> a3562aa0b991
Step 7/11 : WORKDIR application
 ---> Using cache
 ---> a71643e49255
Step 8/11 : COPY --from=builder application/dependencies/ ./
 ---> Using cache
 ---> 01abc9655f2d
Step 9/11 : COPY --from=builder application/snapshot-dependencies/ ./
 ---> Using cache
 ---> 75a072a91176
Step 10/11 : COPY --from=builder application/application/ ./
 ---> c2b6469091f0
Step 11/11 : ENTRYPOINT ["java", "org.springframework.boot.loader.JarLauncher"]
 ---> Running in 7e4922e3f93d
Removing intermediate container 7e4922e3f93d
 ---> 49522222e638
Successfully built 49522222e638
Successfully tagged spring-docker:1.0.3

查看 2.3 的分层

[root@master demo5]# docker history 49522222e638
IMAGE               CREATED             CREATED BY                                      SIZE                COMMENT
49522222e638        8 minutes ago       /bin/sh -c #(nop)  ENTRYPOINT ["java" "org.s…   0B
c2b6469091f0        8 minutes ago       /bin/sh -c #(nop) COPY dir:d414716117e4bcaac…   3.95kB
75a072a91176        9 minutes ago       /bin/sh -c #(nop) COPY dir:8b993266a653e9e77…   0B
01abc9655f2d        9 minutes ago       /bin/sh -c #(nop) COPY dir:ad93c3ca68c6d39b5…   16.8MB
a71643e49255        9 minutes ago       /bin/sh -c #(nop) WORKDIR /application          0B
a3562aa0b991        18 months ago       /bin/sh -c set -x  && apk add --no-cache   o…   99.3MB
<missing>           18 months ago       /bin/sh -c #(nop)  ENV JAVA_ALPINE_VERSION=8…   0B
<missing>           18 months ago       /bin/sh -c #(nop)  ENV JAVA_VERSION=8u212       0B
<missing>           18 months ago       /bin/sh -c #(nop)  ENV PATH=/usr/local/sbin:…   0B
<missing>           18 months ago       /bin/sh -c #(nop)  ENV JAVA_HOME=/usr/lib/jv…   0B
<missing>           18 months ago       /bin/sh -c {   echo '#!/bin/sh';   echo 'set…   87B
<missing>           18 months ago       /bin/sh -c #(nop)  ENV LANG=C.UTF-8             0B
<missing>           18 months ago       /bin/sh -c #(nop)  CMD ["/bin/sh"]              0B
<missing>           18 months ago       /bin/sh -c #(nop) ADD file:a86aea1f3a7d68f6a…   5.53MB

可以看到，已经进行了分层，并不是整个 jar 包构建。

总结

介绍了 Spring Boot 生成镜像的方式，比较多种生成镜像方式后镜像的大小。

posted @ 2020-11-29 17:04 jiangbo4444 阅读(373) 评论(0) 编辑收藏举报

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波尔

【Docker】Spring Boot 和 Docker

环境

编写 Spring Boot 服务

定义 pom.xml

定义接口

打包并上传到服务器

生成镜像

定义 Dockerfile

生成 1.0.0 镜像

生成 1.0.1 镜像

镜像的大小

分别导出镜像

一起导出镜像

分层构建镜像

定义构建文件

使用分层构建

启动并验证功能

分层减少体积

构建分层 1.0.1 版本

比较分层的大小

spring 2.3 构建镜像

直接构建镜像

生成分层 jar

查看分层

定义 Dockerfile

整包生成镜像

查看 2.3 的分层

总结

公告