AWS Auto Stop Start EC2 Instances

In the below post we will create a simple Lambda function to Auto STOP/START EC2 instances.

Step-1
Before we create a lambda function we need to have a role that has access to our EC2 instances.

Go ahead and create a IAM role with appropriate permissions to stop/start the EC2 instances, you can either use the built-in policies or create a custom policy for this role.

 


Step-2
Now create a lambda function, choose option author from scratch as we will use custom code to stop/start the instances.











copy/paste the below code into the lmbda function, remember to replace the region & instance ids.


import boto3
region = 'us-east-2'
instances = ['i-00XXXXXX14f6f']

def lambda_handler(event, context):
    ec2 = boto3.client('ec2', region_name=region)
    ec2.start_instances(InstanceIds=instances)
    print 'started your instances: ' + str(instances)


Under roles select the IAM role you created for this function and change the timeout to at least 20 seconds.










Save and test the function.

You should see a successful message.























Now create a stop function to stop the EC2 instances. Follow step-2 except the in the code you will replace start command with stop command


import boto3
region = 'us-east-2'
instances = ['i-00XXXXXX14f6f']

def lambda_handler(event, context):
    ec2 = boto3.client('ec2', region_name=region)
    ec2.stop_instances(InstanceIds=instances)
    print 'stopped your instances: ' + str(instances)


Step-3:
Now  create Cloud Watch events that will trigger the lambda functions that were created in Step2.






















Create a new rule for the stop function :

















Here I have selected cron expression, you can select which ever is convenient for you.











More about schedule expressions can be found here:
https://docs.aws.amazon.com/AmazonCloudWatch/latest/events/ScheduledEvents.html


****Remember scheduled events in CloudWatch uses default timezone as UTC




Repeat step-4 for start function so that the ec2 instances are started at a desired interval:

Validation:

Instance is stopped at the specified time: