Spring Boot 2.0 (d): Use Docker deployment Spring Boot

Reprinted from "pure smile": https://blog.csdn.net/ityouknow/article/details/79606926

Docker technology development services to micro landing provides a more convenient environment, using Spring Boot Docker deployment is very simple, in this article we take a simple learning.

First, build a simple Spring Boot project, and then add Docker support to the project, and finally deploying the project.

A simple Spring Boot project

In pom.xmlusing the depending Spring Boot 2.0

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.0.RELEASE</version>
</parent>
  
  

  
  

   
   
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Adding web testing and dependence

<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>
</dependencies>
  
  

  
  

   
   
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Create a DockerController, in which there is a index()method that returns the visit to:Hello Docker!

@RestController
public class DockerController {

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

  
  

   
   
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Startup class

@SpringBootApplication
public class DockerApplication {

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

  
  

   
   
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After completion of the project started, after a successful start to put the browser to ask: http://localhost:8080/page return: Hello Docker!, Description Spring Boot project is properly configured.

Spring Boot project to add support for Docker

In pom.xml-propertiesadding image name in Docker

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

  
  

   
   
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plugins added Docker build plug-ins:

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
        <!-- Docker maven plugin -->
        <plugin>
            <groupId>com.spotify</groupId>
            <artifactId>docker-maven-plugin</artifactId>
            <version>1.0.0</version>
            <configuration>
                <imageName>${docker.image.prefix}/${project.artifactId}</imageName>
                <dockerDirectory>src/main/docker</dockerDirectory>
                <resources>
                    <resource>
                        <targetPath>/</targetPath>
                        <directory>${project.build.directory}</directory>
                        <include>${project.build.finalName}.jar</include>
                    </resource>
                </resources>
            </configuration>
        </plugin>
        <!-- Docker maven plugin -->
    </plugins>
</build>
  
  

  
  

   
   
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In the directory src/main/dockercreated Dockerfile files, Dockerfile file that explains how to build the image.

FROM openjdk:8-jdk-alpine
VOLUME /tmp
ADD spring-boot-docker-1.0.jar app.jar
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]
  
  

  
  

   
   
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This Dockerfile file is very simple, basic building Jdk environment, adding to the mirror in Spring Boot Jar, explain briefly:

• FROM, indication Jdk8 environment based mirroring, if the mirror is not local will download from DockerHub
• VOLUME, VOLUME points to a /tmpdirectory, because the Spring Boot using the built-in Tomcat container, Tomcat is used by default /tmpas the working directory. The effect of this command is: in the host /var/lib/dockercreates a temporary file directory and put it in the container linked to the /tmpdirectory
• ADD, copy and rename files
• EntryPoint, Tomcat in order to shorten the startup time, adding java.security.egdsystem properties directed /dev/urandomas EntryPoint

Add this Spring Boot project Docker dependence is complete.

Construction of packing Environment

We need to have a Docker environment to package Spring Boot project, set up in the Windows environment Docker lot of trouble, so I am here as an example to Centos 7.

Docker installation environment

installation

yum install docker
  
  

  
  

   
   
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After installation is complete, use the following command to start the docker services, and set it to boot:

ervice docker start
chkconfig docker on

#LCTT 译注：此处采用了旧式的 sysv 语法，如采用CentOS 7中支持的新式 systemd 语法，如下：
systemctl  start docker.service
systemctl  enable docker.service
  
  

  
  

   
   
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Use Docker China Accelerator

vi  /etc/docker/daemon.json

#添加后：
{
    "registry-mirrors": ["https://registry.docker-cn.com"],
    "live-restore": true
}
  
  

  
  

   
   
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Restart docker

systemctl restart docker
  
  

  
  

   
   
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Enter docker versionreturns the version information is properly installed.

Install the JDK

yum -y install java-1.8.0-openjdk*
  
  

  
  

   
   
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Configuration environment variable
to open the vim /etc/profile
Add about content

export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64 
export PATH=$PATH:$JAVA_HOME/bin 
  
  

  
  

   
   
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After modifications are complete, to take effect

source /etc/profile
  
  

  
  

   
   
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Enter java -versionreturns the version information is properly installed.

MAVEN installation

download:http://mirrors.shu.edu.cn/apache/maven/maven-3/3.5.2/binaries/apache-maven-3.5.2-bin.tar.gz

## 解压
tar vxf apache-maven-3.5.2-bin.tar.gz
## 移动
mv apache-maven-3.5.2 /usr/local/maven3
  
  

  
  

   
   
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Modify environment variables, in /etc/profile, add the following lines

MAVEN_HOME=/usr/local/maven3
export MAVEN_HOME
export PATH=${PATH}:${MAVEN_HOME}/bin
  
  

  
  

   
   
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Remember execution source /etc/profileenvironment variables to take effect.

Enter mvn -versionreturns the version information is properly installed.

So that the entire build environment to configure complete.

Use Docker deployment Spring Boot project

The program spring-boot-dockercopies the server, packaged into the project path under test.

#打包
mvn package
#启动
java -jar target/spring-boot-docker-1.0.jar
  
  

  
  

   
   
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After seeing the Spring Boot boot environment configuration log shows that there is no problem, then we use DockerFile build a mirror.

mvn package docker:build
  
  

  
  

   
   
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The first building may be a bit slow, when you see the following when building a successful show:

...
Step 1 : FROM openjdk:8-jdk-alpine
 ---> 224765a6bdbe
Step 2 : VOLUME /tmp
 ---> Using cache
 ---> b4e86cc8654e
Step 3 : ADD spring-boot-docker-1.0.jar app.jar
 ---> a20fe75963ab
Removing intermediate container 593ee5e1ea51
Step 4 : ENTRYPOINT java -Djava.security.egd=file:/dev/./urandom -jar /app.jar
 ---> Running in 85d558a10cd4
 ---> 7102f08b5e95
Removing intermediate container 85d558a10cd4
Successfully built 7102f08b5e95
[INFO] Built springboot/spring-boot-docker
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 54.346 s
[INFO] Finished at: 2018-03-13T16:20:15+08:00
[INFO] Final Memory: 42M/182M
[INFO] ------------------------------------------------------------------------
  
  

  
  

   
   
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Use docker imagesthe command to view the constructed image:

docker images
REPOSITORY                      TAG                 IMAGE ID            CREATED             SIZE
springboot/spring-boot-docker   latest              99ce9468da74        6 seconds ago       117.5 MB
  
  

  
  

   
   
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springboot/spring-boot-docker Is that we build a good image, the next step is to run the Mirror

docker run -p 8080:8080 -t springboot/spring-boot-docker
  
  

  
  

   
   
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After the startup is complete we use docker psto view mirror are running:

docker ps
CONTAINER ID        IMAGE                           COMMAND                  CREATED             STATUS              PORTS                    NAMES
049570da86a9        springboot/spring-boot-docker   "java -Djava.security"   30 seconds ago      Up 27 seconds       0.0.0.0:8080->8080/tcp   determined_mahavira
  
  

  
  

   
   
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We can see the vessel being built in the running, visit your browser: http://192.168.0.x:8080/return

Hello Docker!
  
  

  
  

   
   
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Instructions Docker deployment Spring Boot project success!

Sample Code -github

Sample code - Code Cloud

reference

The Boot Docker with the Spring
Docker: the Spring application release to the Boot Docker