Step-by-Step Guide to Deploying a Spring Boot Application with Docker

IDEA is a powerful Java IDE, Spring Boot is the most popular micro‑service framework in the Java ecosystem, and Docker is the hottest container technology; combining them creates a seamless development workflow.

1. Development Preparation

1. Docker Installation

You can refer to:

https://docs.docker.com/install/

2. Configure Docker Remote Connection Port

vi /usr/lib/systemd/system/docker.service

Locate the ExecStart line and append -H tcp://0.0.0.0:2375 at the end, as shown in the screenshot.

3. Restart Docker

systemctl daemon-reload
systemctl start docker

4. Open Port

firewall-cmd --zone=public --add-port=2375/tcp --permanent

5. Install IDEA Plugins and Restart

6. Connect to Remote Docker

1. Edit Configuration

2. Fill Remote Docker Address

3. Connection Successful – Containers and Images Listed

2. Create Project

1. Create Spring Boot Project

Project structure diagram:

1. Configure pom.xml

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>docker-demo</groupId>
    <artifactId>com.demo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.2.RELEASE</version>
        <relativePath />
    </parent>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <docker.image.prefix>com.demo</docker.image.prefix>
        <java.version>1.8</java.version>
    </properties>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>com.spotify</groupId>
                <artifactId>docker-maven-plugin</artifactId>
                <version>1.0.0</version>
                <configuration>
                    <dockerDirectory>src/main/docker</dockerDirectory>
                    <resources>
                        <resource>
                            <targetPath>/</targetPath>
                            <directory>${project.build.directory}</directory>
                            <include>${project.build.finalName}.jar</include>
                        </resource>
                    </resources>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-antrun-plugin</artifactId>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <configuration>
                            <tasks>
                                <copy todir="src/main/docker" file="target/${project.artifactId}-${project.version}.${project.packaging}"/>
                            </tasks>
                        </configuration>
                        <goals>
                            <goal>run</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
    </dependencies>
</project>

2. Create Docker Directory and Dockerfile

FROM openjdk:8-jdk-alpine
ADD *.jar app.jar
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]

3. Create application.properties in resources

logging.config=classpath:logback.xml
logging.path=/home/developer/app/logs/
server.port=8990

4. Create DockerApplication Class

@SpringBootApplication
public class DockerApplication {
    public static void main(String[] args) {
        SpringApplication.run(DockerApplication.class, args);
    }
}

5. Create DockerController Class

@RestController
public class DockerController {
    static Log log = LogFactory.getLog(DockerController.class);

    @RequestMapping("/")
    public String index() {
        log.info("Hello Docker!");
        return "Hello Docker!";
    }
}

6. Add Additional Configuration

Image tag: specifies image name docker-demo and tag 1.1.

Bind ports: maps host port to container port in the form [hostPort]:[containerPort].

Bind mounts: mounts a host directory into the container; the Spring Boot logs are written to /home/developer/app/logs/ inside the container, so mounting a host directory persists the logs outside the container.

7. Maven Package

8. Run

9. Run Success

10. Browser Access

11. Log View

Thus, deploying a Spring Boot project to Docker via IDEA is accomplished easily; it is surprising how simple and convenient deploying a Java web application can be.

Source: juejin.im/post/5d026212f265da1b8608828b

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