07. Lab - Cloud Watch

# Cloud Watch

In this hands-on exercise, you will create a Cloud Watch event to notify via an SNS topic when an EC2 instance is created.

Prerequisites:

• AWS account
• SNS Topic created in previous lab

Topics Covered:

By the end of this lab, you will be able to:

• Create Cloud Watch event to react to the creation of an Amazon EC2 instance
• Send SNS notification via Cloud Watch when an event occurs

Steps:

1. Create CloudWatch Rule
   • On the AWS Management Console page, type cloud watch in the Find Services box and then select CloudWatch. The CloudWatch Dashboard appears.
   • On the left-hand menu, under Events, select Rules.
   • Click Create rule.
   • For Service Name, select EC2.
   • For the Event Type, select EC2 Instance State-change Notification.
   • Select the Specific state(s) radio button. Select running from the drop-down box.
     Note: This configures the rule to trigger whenever an Amazon EC2 instance changes to the running state, which happens when an instance is launched or started.
   • On the right-hand side of the screen, in the Target section, add a target by clicking on Add target.
   • In the drop-down, change Lambda function to SNS topic.
   • For the Topic, select the topic you created in the SNS hands-on exercise.
     Important: If the Topic doesn’t appear, the Access policy – optional section doesn’t have the correct permissions to allow other services to access the Topic.
   • Scroll down and click the Configure details.
   • Enter a name in the Name field. Ensure the state is Enabled. Click Create rule.
2. Test CloudWatch Rule
   • Navigate to the EC2 console page, by clicking on Services in the upper left-hand menu. Type EC2 in the text box and click on EC2 found in the search results.
   • On the EC2 Dashboard page, click on Instances in the left-hand navigation.
   • Click Launch Instance.
   • Select the Amazon Linux 2 AMI (HVM), SSD Volume Type Amazon Machine Image (AMI).
     Important: You are free to choose a different AMI, but to avoid excessive charges, pick one that says, Free Tier Eligible.
   • For the Instance Type, select the free-tier instance type of t2.micro.
   • Click Review and Launch.
   • Click Launch.
   • Generate and download a new key pair and then launch the instance.
   • Click Launch Instances.
   • Click on View Instances.
   • Once the Instance state changes to Running, check your email client for an email alert from the SNS Topic.
3. Cleanup & Disable EC2 Instance and Cloud Watch Rule
   • To avoid recurring charges for leaving an instance running, let’s disable the EC2 instance.
   • From the EC2 Dashboard, select the instance just created, click Actions, then Instance State, and then select Terminate.
   • To avoid recurring charges for leaving the Cloud Watch rule running, let’s disable it.
   • From the SNS Dashboard, select Rules from under the Events section.
   • Select the Rule you just created, by clicking the radio button next to the Rule.
   • Click on the Actions button, and select Delete.