Lambda to rotate the SSH keys using Secrets Manager.

Initial code is taken from https://github.com/aws-samples/aws-secrets-manager-ssh-key-rotation/tree/master/lambda. Code is modified to add SSH Public key to an S3 Object, which can be pulled by the new EC2 instances which come up (due to auto-scaling)

cloudformation.yaml is a Cloud Formation script to create the Lambda Function in AWS.

In cloudformation.yaml, please change few of the parameters (look for FIXME in cloudformation.yaml) based on your setup before providing the script to AWS Cloud Formation.

Following parameters need to be changed:

• S3 Bucket where Public key will be stored
• S3 object where Public key will be stored
• Usernames for the Linux User that is used to log into the Workers
• S3 URI of Lambda code
• ARN of S3 Bucket where Public key will be stored
• Security Group IDs
• Subset IDs

Please go though the following blog for detailed step by step procedure to setup https://medium.com/@singhamrit/ec2-mfa-ssh-key-rotation-fddc807f9318