Using Java with AWS Lambda-Implementation-Stop / Launch EC2

Thing you want to do

Start / stop EC2 with Java running on Lambda (Try writing ↓ in Java and customize it a little. https://aws.amazon.com/jp/premiumsupport/knowledge-center/start-stop-lambda-cloudwatch/)

Using Java with AWS Lambda Table of Contents

・ Eclipse Preparation ・ Registration execution (someday) -Implementation-Stop / Start EC2 -Implementation-Check CloudWatch arguments -Implementation Tips --Get Instance Name from Reagion and Instance ID

Create a class for the time being

Since I made it possible to create a sample class in Eclipse last time, Use it to create a Lambda project with input type "Custom".

Here is what you can do with

LambdaFunctionHandler.java

	package com.amazonaws.lambda.demo;

	import com.amazonaws.services.lambda.runtime.Context;
	import com.amazonaws.services.lambda.runtime.RequestHandler;

	public class LambdaFunctionHandler implements RequestHandler<Object, String> {

	    @Override
	    public String handleRequest(Object input, Context context) {
	        context.getLogger().log("Input: " + input);

	        // TODO: implement your handler
	        return "Hello from Lambda!";
	    }
	}

Since the handleRequest method is created, write the content you want to execute with Lambda. See below for handler description https://docs.aws.amazon.com/ja_jp/lambda/latest/dg/java-handler.html You can receive json as an argument. https://docs.aws.amazon.com/ja_jp/lambda/latest/dg/java-handler-pojo.html

Go to EC2

Create an EC2 object

//Create an EC2 object
AmazonEC2 ec2 = AmazonEC2ClientBuilder.standard().withRegion("us-east-1").build();

Now you can work with EC2 in the argument region. See here for region code https://docs.aws.amazon.com/ja_jp/general/latest/gr/rande.html I won't use it this time, but since Enum is also prepared under the name Regions, the class below can also be used. com.amazonaws.regions.Regions

Launch an instance

//Start the instance ID stored in the argument list
StartInstancesResult ret = ec2.startInstances(new StartInstancesRequest(instanceIdList));

Now you can launch the instance ID in the List.

Stop the instance

//Stop the instance ID stored in the argument list
StopInstancesResult ret = ec2.stopInstances(new StopInstancesRequest(instanceIdList));

You can stop the instance ID of List in the same way as starting. Since AmazonWebServiceResult is inherited by the return value of both start and stop, it can be done as below.

AmazonWebServiceResult<?> ret 

Here is the finished product

Make the argument like ↓ so that you can operate on multiple regions and instances.

{"targets":[
    {
         "action":"start"
        ,"targetReagion":"us-east-1"
        ,"targetInstances":"x-xxxxxxxxxxxxx"
    }
    ,{
         "action":"stop"
        ,"targetReagion":"ap-northeast-1"
        ,"targetInstances":"y-yyyyyyyyyyy"
    }
]}

In the example of this argument, start an instance called x-xxxxxxxxxxxxx in northern Virginia, Stop the y-yyyyyyyyyyy instance in Tokyo.

ActionEC2Instances

package com.amazonaws.lambda.demo;

import java.util.ArrayList;
import java.util.List;

import com.amazonaws.AmazonWebServiceResult;
import com.amazonaws.services.ec2.AmazonEC2;
import com.amazonaws.services.ec2.AmazonEC2ClientBuilder;
import com.amazonaws.services.ec2.model.StartInstancesRequest;
import com.amazonaws.services.ec2.model.StopInstancesRequest;
import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;

import com.amazonaws.lambda.demo.ActionEC2Instances.Input;
import com.amazonaws.lambda.demo.ActionEC2Instances.Output;

public class ActionEC2Instances implements RequestHandler<Input, Output> {

	@Override
	public Output handleRequest(Input input, Context context) {
		context.getLogger().log("Input : " + input);
		Output output = new Output();

		for (Target action : input.targets) {
			output.result.add(doAction(action));
		}

		return output;
	}

	private String doAction(Target target) {
		AmazonEC2 ec2 = AmazonEC2ClientBuilder.standard().withRegion(target.targetReagion).build();
		List<String> instances = target.targetInstances;

		AmazonWebServiceResult<?> ret = null;
		if ("start".equals(target.action)) {
			ret = ec2.startInstances(new StartInstancesRequest(instances));

		} else if ("stop".equals(target.action)) {
			ret = ec2.stopInstances(new StopInstancesRequest(instances));

		} else {
			return "Unexpected Action";

		}
		return ret.toString();
	}

	public static class Input {
		public List<Target> targets;

		@Override
		public String toString() {
			StringBuffer sbf = new StringBuffer();
			for (Target target : targets) {
				sbf.append(target);
			}
			return sbf.toString();
		}
	}

	public static class Target {

		private String action;
		private String targetReagion;
		private List<String> targetInstances;

		public String getAction() {
			return action;
		}

		public void setAction(String action) {
			this.action = action;
		}

		public String getTargetReagion() {
			return targetReagion;
		}

		public void setTargetReagion(String targetReagion) {
			this.targetReagion = targetReagion;
		}

		public List<String> getTargetInstances() {
			return targetInstances;
		}

		public void setTargetInstances(List<String> targetInstances) {
			this.targetInstances = targetInstances;
		}

		@Override
		public String toString() {
			StringBuffer sbf = new StringBuffer();
			sbf.append("{action :").append(action).append(" targetReagion :").append(targetReagion)
					.append(" targetInstances :").append(targetInstances).append("}");

			return sbf.toString();
		}

	}

	public static class Output {
		public List<String> result = new ArrayList<String>();
	}
}

Added pom

<dependency>
	<groupId>com.amazonaws</groupId>
	<artifactId>aws-java-sdk-core</artifactId>
	<version>1.11.719</version>
</dependency>
<dependency>
	<groupId>com.amazonaws</groupId>
	<artifactId>aws-lambda-java-events</artifactId>
	<version>1.3.0</version>
</dependency>
<dependency>
	<groupId>com.amazonaws</groupId>
	<artifactId>aws-lambda-java-core</artifactId>
	<version>1.1.0</version>
</dependency>
<dependency>
	<groupId>com.amazonaws</groupId>
	<artifactId>aws-java-sdk-ec2</artifactId>
	<version>1.11.602</version>
	<scope>compile</scope>
</dependency>