alarms using ec2 actions

instance.ts

import * as cdk from "@aws-cdk/core";
import getEnv from "../../config";
import * as ec2 from "@aws-cdk/aws-ec2";
import * as sns from "@aws-cdk/aws-sns";
import * as cw from "@aws-cdk/aws-cloudwatch";
import { EmailSubscription } from "@aws-cdk/aws-sns-subscriptions";
import { SnsAction, Ec2InstanceActions, Ec2Action } from "@aws-cdk/aws-cloudwatch-actions";
import { Stack, StackProps, Duration } from "@aws-cdk/core";

export class TestStack extends Stack {
  constructor(
    scope: cdk.Construct,
    id: string,
    props: StackProps
  ) {
    super(scope, id, props);

    // VPC
    const vpc = ec2.Vpc.fromLookup(this, "import-vpc", {
      vpcName: getEnv(this, "vpcName"),
    });

    //SG
    const securityGroup = new ec2.SecurityGroup(this, "ec2-sg-common", {
      vpc,
    });
    securityGroup.addIngressRule(
      ec2.Peer.ipv4("192.168.0.0/16"),
      ec2.Port.tcp(22),
      "Allow ssh Traffic"
    );

    const instance = new ec2.Instance(this, id, {
      instanceType: new ec2.InstanceType("t2.nano"),
      vpc: vpc,
      machineImage: ec2.MachineImage.lookup({
        name: getEnv(this, "amiMaster"),
        owners: [getEnv(this, "amiAccount"),],
      }),
      keyName: 'vy-qa',
      securityGroup
    });
   
    // Alarm creation
    const alarm = new cw.Alarm(this, "statusAlarm", {
      metric: new cw.Metric({
        namespace: "AWS/EC2",
        metricName: "StatusCheckFailed",
        dimensions: {
          InstanceId: instance.instanceId,
        },
        period: Duration.minutes(5),
        statistic: "max",
      }),
      threshold: 0.5,
      evaluationPeriods: 1,
    });

    // When alarm goes from OK to KO, it will trigger REBOOT action
    alarm.addAlarmAction(
      new Ec2Action(Ec2InstanceActions.REBOOT)
    );

    // SNS topic creation that will send an email on Publish event
    const autorecoveryTopic = new sns.Topic(this, "AutorecoveryTopic", {
      displayName: "Autorecovery Alarms",
    });
    autorecoveryTopic.addSubscription(
      new EmailSubscription("[email protected]")
    );
    const emailAction = new SnsAction(autorecoveryTopic);

    // Alarm will publish in SNS topic when its triggered (OK->KO) and comes back to normal (KO->OK)
    alarm.addAlarmAction(emailAction);
    alarm.addOkAction(emailAction);
  }
}