gs-spring-boot-docker

Built using...

A Mac
Atom
Java JDK 1.8
Gradle 2.10

The steps...

Create a project folder

mkdir gs-spring-boot-docker
cd gs-spring-boot-docker

Create a Gradle build script

touch build.gradle
atom build.gradle

Copy the contents from this Initial Gradle build script to the build.gradle file

Create the project directory structure

mkdir -p src/main/java/hello

Create a domain class

touch src/main/java/hello/Application.java
atom src/main/java/hello/Application.java

Add the following

package hello;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.bind.RelaxedPropertyResolver;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
public class Application {

	@RequestMapping("/")
	public String home() {
		return "Hello Docker World";
	}


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

}

Run it

The one liner

gradle bootRun

Build and run

gradle Build && java -jar build/libs/gs-spring-boot-docker-0.1.0.jar

Go to http://localhost:8080/ to see your "Hello Docker World" message.

Containerize It

touch src/main/docker/Dockerfile
atom src/main/docker/Dockerfile

Add the following

FROM frolvlad/alpine-oraclejdk8:slim
VOLUME /tmp
ADD gs-spring-boot-docker-0.1.0.jar app.jar
RUN sh -c 'touch /app.jar'
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]

Update the Gradle build script

buildscript {
...
  dependencies {
      ...
      classpath('se.transmode.gradle:gradle-docker:1.2')
  }
}

group = 'channie'

...
apply plugin: 'docker'

task buildDocker(type: Docker, dependsOn: build) {
  push = false
  applicationName = jar.baseName
  dockerfile = file('src/main/docker/Dockerfile')
  doFirst {
    copy {
      from jar
      into stageDir
    }
  }
}

Build it and push it

gradle build buildDocker

Run it

docker run -p 8080:8080 -t channie/gs-spring-boot-docker

Your app will be available on http://localhost:8080/

Although...

On a mac its not likely to be on localhost, run...

docker-machine ip name-of-your-docker-env

This will give you the ip of your docker machine environment, which will still be exposed on 8080 i.e.

http://docker-machine-ip:8080/

418error/gs-spring-boot-docker

gs-spring-boot-docker

Built using...

The steps...