Integrate Spring Boot and EC2 Using Cloudformation

In a previous blog, we integrated a Spring Boot application with Elastic beanstalk. The application was a servlet-based application responding to requests.

In this tutorial, we are going to deploy a Spring Boot application that executes some scheduled tasks on an EC2 instance.

The application will be pretty much the same application taken from the official Spring guide with some minor differences in packages.

The name of our application will be ec2-deployment:

 rootProject.name = 'ec2-deployment' 

We will schedule a task to our Spring Boot application.

package com.gkatzioura.deployment.task; 
import org.slf4j.Logger; 
import org.slf4j.LoggerFactory; 
import org.springframework.scheduling.annotation.Scheduled; 
import org.springframework.stereotype.Component; 
/** * Created by gkatzioura on 12/16/16. */ 
@Component public class SimpleTask 
{ 
  private static final Logger LOGGER = LoggerFactory.getLogger(SimpleTask.class);
 @Scheduled(fixedRate = 5000) 

 public void reportCurrentTime() 
 { 
   LOGGER.info("This is a simple task on ec2"); 
 } 
} 

The next step is to build the application and deploy it to our s3 bucket.

 gradle build aws s3 cp build/libs/ec2-deployment-1.0-SNAPSHOT.jar s3://{your bucket name}/ec2-deployment-1.0-SNAPSHOT.jar 

What comes next is a bootstrapping script in order to run our application once the server is up and running.

 #!/usr/bin/env bash aws s3 cp s3://{bucket with code}/ec2-deployment-1.0-SNAPSHOT.jar /home/ec2-user/ec2-deployment-1.0-SNAPSHOT.jar sudo yum -y install java-1.8.0 sudo yum -y remove java-1.7.0-openjdk cd /home/ec2-user/ sudo nohup java -jar ec2-deployment-1.0-SNAPSHOT.jar > ec2dep.log 

This script is pretty much self-explanatory. We download the application from the bucket we uploaded it from previously, we install the Java version needed, and then we run the application (this script serves us for example purposes; there are certainly many ways to set up your Java application running on Linux).

The next step would be to proceed to our Cloudformation script. Since we will download our application from s3, it is essential to have an IAM policy that will allow us to download items from the s3 bucket we used previously. Therefore, we will create a role with the policy needed.

 "RootRole": { "Type": "AWS::IAM::Role", 
              "Properties": { "AssumeRolePolicyDocument": 
                             { "Version" : "2012-10-17", 
                              "Statement": [ 
                                { "Effect": "Allow", "Principal": 
                                 { "Service": [ "ec2.amazonaws.com" ] }, 
                                 "Action": [ "sts:AssumeRole" ] } ] }, 
                             "Path": "/", 
                             "Policies": [
                               { "PolicyName": "root", 
                                "PolicyDocument": 
                                { "Version" : "2012-10-17", "Statement": 
                                 [ { "Effect": "Allow", "Action": 
                                    [ "s3:Get*", "s3:List*" ],
                                    "Resource": {"Fn::Join" : [ "",
                                                               [ "arn:aws:s3:::",
{"Ref":"SourceCodeBucket"},"/*"] ] } } ] } } ] } } 

The next step is to encode our bootstrapping script to Base64 in order to be able to pass it as user data. Once the EC2 instance is up and running, it will run the Shell commands previously specified.

The last step is to create our instance profile and specify the EC2 instance to be launched.

 "RootInstanceProfile": 
{ "Type": "AWS::IAM::InstanceProfile", 
 "Properties": 
 { "Path": "/", "Roles": [ { "Ref": "RootRole" } ] } }, 
"Ec2Instance":{ "Type":"AWS::EC2::Instance", 
             "Properties":{ "ImageId":"ami-9398d3e0", 
                           "InstanceType":"t2.nano", 
                           "KeyName":"TestKey", 
                           "IamInstanceProfile": 
                           {"Ref":"RootInstanceProfile"}, 
"UserData":"IyEvdXNyL2Jpbi9lbnYgYmFzaA0KYXdzIHMzIGNwIHMzOi8ve2J1Y2tldCB3aXRoIGNvZGV9L2VjMi1kZXBsb3ltZW50LTEuMC1TTkFQU0hPVC5qYXIgL2hvbWUvZWMyLXVzZXIvZWMyLWRlcGxveW1lbnQtMS4wLVNOQVBTSE9ULmphcg0Kc3VkbyB5dW0gLXkgaW5zdGFsbCBqYXZhLTEuOC4wDQpzdWRvIHl1bSAteSByZW1vdmUgamF2YS0xLjcuMC1vcGVuamRrDQpjZCAvaG9tZS9lYzItdXNlci8NCnN1ZG8gbm9odXAgamF2YSAtamFyIGVjMi1kZXBsb3ltZW50LTEuMC1TTkFQU0hPVC5qYXIgPiBlYzJkZXAubG9n" 
                          } } 

KeyName stands for the SSH key name, in case you want to log into the ec2 instance.

So, we are good to go and create our Cloudformation stack. You have to add the CAPABILITY_IAM flag.

 aws s3 cp ec2spring.template s3://{bucket with templates}/ec2spring.template aws cloudformation create-stack --stack-name SpringEc2 --parameters ParameterKey=SourceCodeBucket,ParameterValue={bucket with code} --template-url https://s3.amazonaws.com/{bucket with templates}/ec2spring.template --capabilities CAPABILITY_IAM 

That’s it. Now you have your spring application up and running on top of an EC2 instance.

You can download the source code from GitHub.