Analysis of the principles of docker in springboot

1. Add maven configuration

<properties>
    <docker.image.prefix>ms4t</docker.image.prefix>
  </properties>

  <build>
    <finalName>eureka</finalName>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
      <plugin>
        <groupId>com.spotify</groupId>
        <artifactId>dockerfile-maven-plugin</artifactId>
        <version>1.3.6</version>
        <configuration>
          <repository>${docker.image.prefix}/${project.artifactId}</repository>
          <buildArgs>
            <JAR_FILE>target/${project.build.finalName}.jar</JAR_FILE>
          </buildArgs>
        </configuration>
      </plugin>
    </plugins>
  </build>

2. Create Dockerfile

FROM openjdk:8-jdk-alpine
VOLUME /tmp
ARG JAR_FILE
COPY ${JAR_FILE} app.jar
ENTRYPOINT ["java","-jar","/app.jar"]

Parameter explanation:

• FROM : requires a base image, which can be public or private.

• Subsequent builds will be based on this image. If multiple images are created in the same Dockerfile, multiple FROM instructions can be used

• VOLUME configuration A directory with persistence function. A temporary file is created in the host /var/lib/docker directory and linked to the container’s /tmp. The modification step is optional, but it is necessary if it involves file system applications

• . The /tmp directory is used to persist to the Docker data folder, because the embedded Tomcat container used by Spring Boot uses /tmp as the working directory by default

• ARG sets the parameters added when compiling the image. ENV is to set the environment variable of the container

• COPY: only supports copying local files to the container. There is also ADD which is more powerful but more complicated

• ENTRYPOINT Command executed when the container starts

• EXPOSE 8080 Exposed image port

##3. Build

mvn install dockerfile:build

4. Start

docker run -d --name 名称 -p 对外端口:容器端口 镜像ID

The above is the detailed content of Analysis of the principles of docker in springboot. For more information, please follow other related articles on the PHP Chinese website!