vars.json

{
  "aws_access_key": "${AWS_ACCESS_KEY_ID}",
  "aws_secret_key": "${AWS_SECRET_ACCESS_KEY}",
  "vpc_region": "${vpc_region}",
  "vpc_id": "${vpc_id}",
  "vpc_public_sn_id": "${vpc_public_sn_id}",
  "vpc_public_sg_id": "${vpc_public_sg_id}",
  "source_ami": "${source_ami}",
  "instance_type": "${instance_type}",
  "ssh_username": "${ssh_username}"
}