On a previous blog we integrated a spring boot application with elastic beanstalk.
The application was a servlet based application responding to requests.
On this tutorial we are going to deploy a spring boot application, which 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 on packages.
The name of our application will be ec2-deployment
rootProject.name = 'ec2-deployment'
Then 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");
}
}
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 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 you java application running on linux).
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"},"/*"] ] }
} ]
}
} ]
}
}
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.
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 login to 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.
Emmanouil Gkatziouras 