Video
Development Steps
- Create Spring boot application
- Build a simple REST API
- Create Dockerfile
- Build Docker Image
- Run Docker Image in a Container
- Demo
1. Create Spring boot application
Spring Boot provides a web tool called Spring Initializer to bootstrap an application quickly. Just go to https://start.spring.io/ and generate a new spring boot project.
Use the below details in the Spring boot creation:
Project Name: springboot-docker-demo
Project Type: Maven
Choose dependencies: Spring Web
Package name: net.javaguides.springboot
Packaging: Jar
Here is the pom.xml file for your reference:
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.4</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>net.javaguides</groupId>
<artifactId>springboot-docker-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springboot-docker-demo</name>
<description>Demo project for Spring Boot and Docker</description>
<properties>
<java.version>11</java.version>
</properties>
<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>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2. Build a simple REST API
package net.javaguides.springboot;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@SpringBootApplication
@RestController
public class SpringbootDockerDemoApplication {
@GetMapping("/welcome")
public String welcome(){
return "Spring Boot Docker Demo";
}
public static void main(String[] args) {
SpringApplication.run(SpringbootDockerDemoApplication.class, args);
}
}
mvn package
3. Create Dockerfile
# define base docker image
FROM openjdk:11
LABEL maintainer="javaguides.net"
ADD target/springboot-docker-demo-0.0.1-SNAPSHOT.jar springboot-docker-demo.jar
ENTRYPOINT ["java", "-jar", "springboot-docker-demo.jar"]
4. Build Docker Image
Now that we have defined the Dockerfile, let’s build a docker image for our application.docker build -t springboot-docker-demo:latest .
The file path . defines the location of the Dockerfile in the current directory, and the -t argument tags the resulting image, where the repository name is the springboot-docker-demo and the tag is the latest.docker images
rameshfadatare@Rameshs-MacBook-Air springboot-docker-demo % docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
springboot-docker-demo latest 8d61ab5ecfb1 36 seconds ago 667MB
docker-demo latest 09c04b790f98 3 hours ago 667MB
5. Run Docker Image in a Container
docker run -p 8081:8080 springboot-docker-demo
rameshfadatare@Rameshs-MacBook-Air springboot-docker-demo % docker run -p 8081:8080 springboot-docker-demo
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.5.4)
2021-09-03 10:10:38.293 INFO 1 --- [ main] n.j.s.SpringbootDockerDemoApplication : Starting SpringbootDockerDemoApplication v0.0.1-SNAPSHOT using Java 11.0.12 on 520f1f1ab260 with PID 1 (/springboot-docker-demo.jar started by root in /)
2021-09-03 10:10:38.311 INFO 1 --- [ main] n.j.s.SpringbootDockerDemoApplication : No active profile set, falling back to default profiles: default
2021-09-03 10:10:42.814 INFO 1 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2021-09-03 10:10:42.868 INFO 1 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2021-09-03 10:10:42.870 INFO 1 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.52]
2021-09-03 10:10:43.116 INFO 1 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2021-09-03 10:10:43.117 INFO 1 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 4443 ms
2021-09-03 10:10:44.909 INFO 1 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2021-09-03 10:10:45.002 INFO 1 --- [ main] n.j.s.SpringbootDockerDemoApplication : Started SpringbootDockerDemoApplication in 8.99 seconds (JVM running for 10.882)
2021-09-03 10:11:18.099 INFO 1 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet'
2021-09-03 10:11:18.104 INFO 1 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'
2021-09-03 10:11:18.127 INFO 1 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 23 ms
6. Demo
Spring Boot Docker Demo
Hi, I am using war file for my spring boot application. I am not understanding how to add entry point option for the DockerFile.
ReplyDeleteCould you please help?