Comprehensive DevOps Automation: Docker, Jenkins, GitLab, Maven and SpringBoot Deployment Guide

1. Introduction and Purpose

The article introduces a practical DevOps guide that combines Docker commands, Jenkins pipelines, GitLab, Maven, and SpringBoot to achieve automated build and deployment, especially for SpringCloud projects.

2. What is DevOps?

DevOps (Development + Operations) is a set of practices and tools that promote collaboration between software developers and IT operations, enabling faster, more reliable software delivery through automation of build, test, and release processes.

3. Environment Setup Topics

Installing JDK 1.8 on CentOS 7

Installing Maven 3.6.1 on CentOS 7

Installing Git on CentOS 7

Configuring password‑less SSH for GitLab

Deploying GitLab, Docker network, Docker Registry, and Jenkins inside Docker containers

4. Required Preparations

4.1 Project Structure

Create a new SpringBoot project in IDEA or Eclipse.

4.2 SpringBoot Configuration and Code Details

4.2.1 pom.xml Dependencies

<dependencies>
  <!-- SpringBoot starter -->
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter</artifactId>
  </dependency>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <!-- DevTools for hot reload -->
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-devtools</artifactId>
    <scope>runtime</scope>
    <optional>true</optional>
  </dependency>
  <!-- Configuration processor -->
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-configuration-processor</artifactId>
    <optional>true</optional>
  </dependency>
  <!-- Test starter -->
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
  </dependency>
</dependencies>
<build>
  <finalName>springboot</finalName>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-compiler-plugin</artifactId>
      <configuration>
        <source>1.8</source>
        <target>1.8</target>
      </configuration>
    </plugin>
    <plugin>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-maven-plugin</artifactId>
      <executions>
        <execution>
          <goals>
            <goal>repackage</goal>
          </goals>
        </execution>
      </executions>
    </plugin>
    <plugin>
      <groupId>com.spotify</groupId>
      <artifactId>docker-maven-plugin</artifactId>
      <version>0.4.12</version>
      <configuration>
        <dockerDirectory>${project.basedir}</dockerDirectory>
        <resources>
          <resource>
            <targetPath>/</targetPath>
            <directory>${project.build.directory}</directory>
            <include>${project.build.finalName}.jar</include>
          </resource>
        </resources>
      </configuration>
    </plugin>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-jar-plugin</artifactId>
      <configuration>
        <archive>
          <manifest>
            <mainClass>com.flong.SpringbootApplication</mainClass>
          </manifest>
        </archive>
      </configuration>
    </plugin>
  </plugins>
</build>

4.2.2 Fixing "no main manifest attribute" Error

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-jar-plugin</artifactId>
  <configuration>
    <archive>
      <manifest>
        <mainClass>com.flong.SpringbootApplication</mainClass>
      </manifest>
    </archive>
  </configuration>
</plugin>

4.2.3 Environment Variable File (.env)

JAVA_OPTS_DEFAULT=-Xmx512m

4.2.4 Dockerfile for Building the Image

FROM frolvlad/alpine-oraclejdk8:slim
MAINTAINER [email protected]
RUN ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
RUN mkdir -p /home/devsoft/springboot_dev
WORKDIR /home/devsoft/springboot_dev
EXPOSE 7011
ADD ./target/springboot.jar ./
CMD java ${JAVA_OPTS_DEFAULT} -Djava.security.egd=file:/dev/./urandom -jar springboot.jar

4.2.5 build.sh Script

#!/usr/bin/env bash
# Dynamic variables must not contain spaces around '='
IMG_SERVER="$1"
IMG_NAME="$2"
IMG_VERSION="$3"
IMG_PORT="$4"
RUN_EVN="$5"
IMG_PATH="$6"

echo "服务地址：$IMG_SERVER"
echo "工程镜像名称：$IMG_NAME"
echo "工程版本号：$IMG_VERSION"
echo "工程端口：$IMG_PORT"
echo "服务环境：$RUN_EVN"

REGISTRY_URL="192.168.1.235:5000"
IMG_TAR_GZ_PATH="/home/img_tar_gz_path/"

if [ "$IMG_SERVER" != "" ] && [ "$IMG_NAME" != "" ] && [ "$IMG_VERSION" != "" ] && [ "$IMG_PORT" != "" ]; then
  echo ".......进入删除 Container & Images 操作......."
  CONTAINER_ID=$(docker ps -a | grep $IMG_NAME | awk '{print $1}')
  IMAGE_ID=$(docker images | grep $IMG_NAME | awk '{print $3}')
  if [[ "$CONTAINER_ID" != "" ]]; then docker rm -f $CONTAINER_ID; fi
  if [[ "$IMAGE_ID" != "" ]]; then docker rmi -f $IMAGE_ID; fi
  echo ".......进入 Building & Images 操作......."
  docker build -t $IMG_NAME:$IMG_VERSION -f $IMG_PATH"env/"Dockerfile_$RUN_EVN $IMG_PATH
  docker tag $IMG_NAME:$IMG_VERSION $REGISTRY_URL/$IMG_NAME:$IMG_VERSION
  docker push $REGISTRY_URL/$IMG_NAME:$IMG_VERSION
  if [ -d "$IMG_PATH" ]; then echo "已经存在:"$IMG_PATH; else mkdir -p $IMG_PATH; fi
  docker save $IMG_NAME -o $IMG_TAR_GZ_PATH/$IMG_NAME.tar.gz
  echo ".......进入 Running 操作....."
  docker run -d --network default_network --restart=always --env-file=./.env -e spring.profiles.active=$RUN_EVN --expose=$IMG_PORT --name=$IMG_NAME -p $IMG_PORT:$IMG_PORT $IMG_NAME:$IMG_VERSION
  echo ".......Build & Run Finish Success~...."
else
  echo ".......Illegal Command Operation......."
fi

4.2.6 Docker Commands (save, load, tag, push, pull)

docker save 镜像名 -o /path/镜像名.tar.gz
docker load -i /path/镜像名.tar.gz
docker tag 镜像名:版本 私服路径/镜像名:版本
docker push 私服路径/镜像名:版本

4.2.9 Sample Controller

@RestController
public class SimpleController {
    @Value("${runEvn}")
    private String runEvn;

    @GetMapping("/test")
    public String test() {
        return "this spring boot " + runEvn + " date long " + System.currentTimeMillis();
    }
}

5. Single‑Machine Remote Login & Jenkins Deployment

5.1 Special Notes

Demo uses the same machine for Jenkins and the target deployment to save resources.

5.2 Create Maven Project

Use Jenkins "New Item" to create a Maven job.

5.3 Parameterized Build

Add parameters (e.g., server, appName, version, port, env, serverPath).

Configure source code management (GitLab repository).

Set build goals: clean install -U -Dmaven.test.skip=true.

5.4 SSH Publisher Script (single machine)

#!/bin/bash
mkdir -p ${serverPath}
cd ${serverPath}
sh build.sh ${server} ${appName} ${version} ${port} ${env} ${serverPath}

5.5 Build & Deploy Result

Screenshots show successful build logs and running container output.

6. Multi‑Machine Remote Login & Jenkins Deployment

6.1 Special Notes

Demo uses a separate test machine as the deployment target.

6.2 Create Maven Project

Same steps as the single‑machine case.

6.4 SSH Publisher Scripts

docker_server1 (creates directory on remote host)

#!/bin/bash
echo "用户名${userName}"
echo "服务器${server}"
echo "服务器目录${serverPath}"
ssh $server mkdir -p ${targetServerPath}
scp -r ${serverPath}/ ${userName}@${server}:${targetServerPath}

docker_server2 (executes build on remote host)

#!/bin/bash
cd ${serverPath}
sh build.sh ${server} ${appName} ${version} ${port} ${env} ${serverPath}

6.5 Build & Deploy Result

Shows build logs for both machines and successful container deployment.

7. Summary & Recommendations

The article emphasizes that the guide is for reference, encourages readers to consult official documentation, practice hands‑on, and explore further resources such as Docker docs, Maven plugins, and community articles.

References

https://docs.docker.com/engine/reference/commandline/docker/

https://yeasy.gitbooks.io/docker_practice/

https://github.com/spotify/docker-maven-plugin

https://dmp.fabric8.io/

https://github.com/jilongliang/springboot

https://www.cnblogs.com/kakaln/p/7872873.html

https://www.cnblogs.com/lucoo/p/10209892.html