Containerize and deploy spring boot app to aws in 10 mins

In this tutorial, we will create a simple spring boot app, containarize it and deploy to aws. Goal was to create in 10 mins but it took slightly more than 10 mins

Demo screencast

Download code

Code can be downloaded from github

Pre-requisites

• Java JDK 8 or above
• Docker 17 or above
• AWS account
• AWS CLI

Create a simple spring boot app

Go to SPRING INITIALIZR and create a simple spring boot app. For this demo, I choose

• gradle
• Dependency - Web
• appropriate group (org.bpt) and atrtefact names(demo).

Generate project and download.

Compile and run the app

• extract the zip file
• Compile and build

 ./gradlew clean build

• Import the project to your favourite ide
• Add a controller

package org.bpt.demo;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class DemoController {

    @RequestMapping("/greet")
    public String greet() {
        return "hello";
    }
}

• Build the project again

./gradlew clean build

• Run the application
• Go to your favourite browser and access http://localhost:8080/greet You should see the message “hello”

curl localhost:8080/greet

Also check health endpoint

curl localhost:8080/actuator/health

Containerize the spring boot app

• Add a file Dockerfile with following content

FROM openjdk:8-jdk-alpine
VOLUME /tmp
ARG JAR_FILE
COPY ${JAR_FILE} app.jar
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]

Build docker images

You can directly build the above dockerfile but we will use Docker Gradle Plugin so that creating java artefacts and building docker image can be done in one single step.

• Add docker gradle plugin to build.gradle

buildscript {
....
	repositories {
        ....
		maven {
			url "https://plugins.gradle.org/m2/"
		}
	}
	dependencies {
        .....
		classpath('gradle.plugin.com.palantir.gradle.docker:gradle-docker:0.13.0')
        .....
	}
}

....
apply plugin: 'com.palantir.docker'
....


docker {
	dependsOn build
	name "${project.group}/${bootJar.baseName}"
	files bootJar.archivePath
	buildArgs(['JAR_FILE': "${bootJar.archiveName}"])
}

• Build a new image with latest code

./gradlew build docker

• Check that new image is created

docker images -a

• Test image locally

docker run -p 8080:8080 -t org.bpt/demo

Use curl commands above and make sure that application is running successfully. You have successfully created docker image of your application. Please see more information on dockerizing spring boot application (here)[https://spring.io/guides/gs/spring-boot-docker/]

Push image to Amazon Elastic Container Registry(ECR)

• Go to aws console and create a new registry spring-boot-demo

• Get login to ECR

$(aws ecr get-login --no-include-email --region ap-southeast-2)

If you get below error, add permission policy “AmazonEC2ContainerRegistryFullAccess” for the user.

An error occurred (AccessDeniedException) when calling the GetAuthorizationToken operation: User: arn:aws:iam::708464146667:user/Developer1 is not authorized to perform: ecr:GetAuthorizationToken on resource: *

• Tag the docker image

docker tag org.bpt/demo:latest <repo-url>

• Push image to ECR

docker push <repo-url>

• Go to aws console and make sure that the image is present in the repository.

Run the new image in aws

Please check the screencast for demo.

• Create container definition

• Create task definition

• Create Service

• Configure cluster and run it.

Health endpoint configuration is

CMD-SHELL, curl localhost:8080/actuator/health || exit 1

Conclusion

In this demo, we created, dockerized and deployed a simple spring boot application. In a more realistic example, we will probbaly have an API gateway in front of the ECS cluster for authentication/authorization/api management/ throttling/caching etc. This is to show how easy it is to deploy a spring-boot app to aws.