Dockerfile构建Springboot镜像

简介

容器技术大流行的时代，也是docker大流行的时代。

此文章以一个简单的实例为基础，帮助大家学习和了解：如何使用Dockerfile指令构建一个Springboot的Java项目镜像。

提示：实例非常简单，旨在帮助大家了解基础知识，本文的知识在实际工作中肯定是不够用的，还需要自行根据实际情况去学习，感谢您的阅读。

前期准备

Docker环境

Windows请安装Docker Desktop：https://docs.docker.com/desktop/install/windows-install/
Linux请安装Docker：https://docs.docker.com/desktop/install/linux-install/

Springboot项目

源码：learn/java/docker-springboot at main · DingDangDog/learn (github.com)
Jar包下载地址：docker-springboot-1.0.jar.zip
Controller代码示例：

java
package io.github.dingdangdog.controller;

import io.github.dingdangdog.utils.FileUtilOm;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * say hello
 *
 * @author DingDangDog
 * @since 2022/10/4 11:13
 */
@RestController
@RequestMapping("/say")
public class SayController {

    @GetMapping("/hello")
    public String hello(String name) {
        System.out.println(name);
        // 保存文件
        FileUtilOm.saveFile("/tmp/", name, name);
        return "Hello " + name + " !";
    }
}

Dockerfile文件

文件名必须为Dockerfile，无拓展名！！！请放在jar包同级目录下。文件内容如下：

shell
# 基础镜像
FROM openjdk:8-jdk
# 作者声明，原为MAINTAINER，变更为LABEL
# MAINTAINER DingDangDog
LABEL author="DingDangDog"
# 容器卷设置
VOLUME /tmp
# 向基础镜像内添加文件，并重命名为`docker_boot.jar`
add docker-springboot-1.0.jar docker_boot.jar
# 执行前置脚本。据说是修改文件时间？不太明白具体作用，望有大佬指点迷津！
RUN bash -c 'touch /docker_boot.jar'
# 最终执行脚本
ENTRYPOINT ["java", "-jar", "/docker_boot.jar"]
# 暴露端口
EXPOSE 10240

指令解析请参考文章：Dockerfile基础一文通

实例操作

具体操作介绍了Windows和Linux两种方式。

Windows

要求

请阅读上面的前期准备

如下图，运行状态绿色为Docker正在正常运行

docker

构建镜像

在jar包所在文件夹下打开cmd命令行窗口，运行构建命令：
```
shell
docker build -t docker_boot:1.0 .
```
命令解析：
- docker build：构建镜像
- -t docker_boot:1.0 ：-t=--tag，指定镜像名称为docker_boot，版本为1.0
- . ：指定Dockerfile文件在当前文件夹下

构建成功日志如下：

shell
[+] Building 76.3s (9/9) FINISHED
 => [internal] load build definition from Dockerfile                                                               0.0s
 => => transferring dockerfile: 254B                                                                               0.0s
 => [internal] load .dockerignore                                                                                  0.0s
 => => transferring context: 2B                                                                                    0.0s
 => [internal] load metadata for docker.io/library/openjdk:8-jdk                                                   4.6s
 => [auth] library/openjdk:pull token for registry-1.docker.io                                                     0.0s
 => [internal] load build context                                                                                  0.1s
 => => transferring context: 19.65MB                                                                               0.1s
 => [1/3] FROM docker.io/library/openjdk:8-jdk@sha256:86e863cc57215cfb181bd319736d0baf625fe8f150577f9eb58bd937f5  70.8s
 => => resolve docker.io/library/openjdk:8-jdk@sha256:86e863cc57215cfb181bd319736d0baf625fe8f150577f9eb58bd937f54  0.0s
 => => sha256:86e863cc57215cfb181bd319736d0baf625fe8f150577f9eb58bd937f5452cb8 1.04kB / 1.04kB                     0.0s
 => => sha256:3af2ac94130765b73fc8f1b42ffc04f77996ed8210c297fcfa28ca880ff0a217 1.79kB / 1.79kB                     0.0s
 => => sha256:001c52e26ad57e3b25b439ee0052f6692e5c0f2d5d982a00a8819ace5e521452 55.00MB / 55.00MB                  24.0s
 => => sha256:2068746827ec1b043b571e4788693eab7e9b2a95301176512791f8c317a2816a 10.88MB / 10.88MB                  13.1s
 => => sha256:b273004037cc3af245d8e08cfbfa672b93ee7dcb289736c82d0b58936fb71702 7.81kB / 7.81kB                     0.0s
 => => sha256:d9d4b9b6e964657da49910b495173d6c4f0d9bc47b3b44273cf82fd32723d165 5.16MB / 5.16MB                    18.0s
 => => sha256:9daef329d35093868ef75ac8b7c6eb407fa53abbcb3a264c218c2ec7bca716e6 54.58MB / 54.58MB                  43.2s
 => => sha256:d85151f15b6683b98f21c3827ac545188b1849efb14a1049710ebc4692de3dd5 5.42MB / 5.42MB                    25.5s
 => => sha256:52a8c426d30b691c4f7e8c4b438901ddeb82ff80d4540d5bbd49986376d85cc9 210B / 210B                        25.3s
 => => extracting sha256:001c52e26ad57e3b25b439ee0052f6692e5c0f2d5d982a00a8819ace5e521452                          1.9s
 => => sha256:8754a66e005039a091c5ad0319f055be393c7123717b1f6fee8647c338ff3ceb 105.92MB / 105.92MB                68.4s
 => => extracting sha256:d9d4b9b6e964657da49910b495173d6c4f0d9bc47b3b44273cf82fd32723d165                          0.2s
 => => extracting sha256:2068746827ec1b043b571e4788693eab7e9b2a95301176512791f8c317a2816a                          0.2s
 => => extracting sha256:9daef329d35093868ef75ac8b7c6eb407fa53abbcb3a264c218c2ec7bca716e6                          2.1s
 => => extracting sha256:d85151f15b6683b98f21c3827ac545188b1849efb14a1049710ebc4692de3dd5                          0.2s
 => => extracting sha256:52a8c426d30b691c4f7e8c4b438901ddeb82ff80d4540d5bbd49986376d85cc9                          0.0s
 => => extracting sha256:8754a66e005039a091c5ad0319f055be393c7123717b1f6fee8647c338ff3ceb                          2.1s
 => [2/3] ADD docker-springboot-1.0.jar docker_boot.jar                                                            0.3s
 => [3/3] RUN bash -c 'touch /docker_boot.jar'                                                                     0.4s
 => exporting to image                                                                                             0.1s
 => => exporting layers                                                                                            0.1s
 => => writing image sha256:0fcc9c262e90d6a05213ec432924e6835647d233a64ad0747cf7dd406a2a40bd                       0.0s
 => => naming to docker.io/library/docker_boot:1.0                                                                 0.0s

Use 'docker scan' to run Snyk tests against images to find vulnerabilities and learn how to fix them

查看镜像

docker

启动测试

启动容器

docker

调用测试

docker

查看本地文件：

docker

Linux

要求

请阅读上面的 前期准备

构建镜像

在jar包所在文件夹下运行构建命令：
```
shell
docker build -t docker_boot:1.0 .
```
解析：
- docker build：构建镜像
- -t docker_boot:1.0 ：-t=--tag，指定镜像名称为docker_boot，版本为1.0
- . ：指定Dockerfile文件在当前文件夹下

构建成功日志：

shell
Sending build context to Docker daemon  19.65MB
Step 1/7 : FROM openjdk:8-jdk
8-jdk: Pulling from library/openjdk
001c52e26ad5: Pull complete 
d9d4b9b6e964: Pull complete 
2068746827ec: Pull complete 
9daef329d350: Pull complete 
d85151f15b66: Pull complete 
52a8c426d30b: Pull complete 
8754a66e0050: Pull complete 
Digest: sha256:86e863cc57215cfb181bd319736d0baf625fe8f150577f9eb58bd937f5452cb8
Status: Downloaded newer image for openjdk:8-jdk
 ---> b273004037cc
Step 2/7 : MAINTAINER DingDangDog
 ---> Running in 6b19d92591a8
Removing intermediate container 6b19d92591a8
 ---> 8a491c04d897
Step 3/7 : VOLUME /tmp
 ---> Running in 696221f7868c
Removing intermediate container 696221f7868c
 ---> ad7eff7b71e1
Step 4/7 : add docker-springboot-1.0.jar docker_boot.jar
 ---> 77eb15fd7557
Step 5/7 : RUN bash -c 'touch /docker_boot.jar'
 ---> Running in 0704d4fd8ab2
Removing intermediate container 0704d4fd8ab2
 ---> aa9e4ca18365
Step 6/7 : ENTRYPOINT ["java", "-jar", "/docker_boot.jar"]
 ---> Running in 78ae0e314f8f
Removing intermediate container 78ae0e314f8f
 ---> cb6f8c91f76c
Step 7/7 : EXPOSE 10240
 ---> Running in 697a7506c8c8
Removing intermediate container 697a7506c8c8
 ---> 20bafbe3127b
Successfully built 20bafbe3127b
Successfully tagged docker_boot:1.0

查看镜像docker images

docker

启动测试

启动容器

shell
docker run -v /var/local/docker/docker-boot-test/tmp:/tmp -p 10240:10240 -d --name docker_boot_test docker_boot:1.0

调用测试

shell
curl http://localhost:10240/say/hello?name=ddd
# Hello ddd !

查看本地文件：

docker

目录

简介

前期准备

Docker环境

Springboot项目

Dockerfile文件

实例操作

Windows

要求

构建镜像

启动测试

Linux

要求

构建镜像

启动测试