AWS Session Manager Example

A minimal viable Terraform script showcasing deployment of an EC2 instance in a private AWS subnet without internet access, accessible via Session Manager.

Key points are:

• Enable VPC's DNS support
• Create the endpoints for:
  • ec2messages
  • ssm
  • ssmmessages
• The private DNS is enabled on the endpoints
• Endpoints are associated with the subnet
• The security group of the endpoints allows 443 egress
• The Instance profile has the policy AmazonSSMManagedInstanceCore attached
• And of course, The AMI being used needs to have the SSM agent pre-installed