Terraform module for scheduled checking of Terraform drift using Drifter (https://github.com/digirati-labs/drifter), with notifications sent to a Slack webhook and metrics emitted to Cloudwatch.
| Variable | Description | Default | 
|---|---|---|
| prefix | Prefix to give to AWS resources | |
| slack_webhook_url | Slack Webhook URL for notifications | |
| terraform_identifier | Identifier for the Drifter task (e.g. my-tf-repo-master) | |
| terraform_s3_bucket | Name of S3 bucket that the Terraform resides in | |
| terraform_s3_key | S3 Key of the Terraform remote state file | terraform.tfstate | 
| terraform_github_repo | GitHub repository in format user/repo | |
| terraform_github_branch | GitHub repository branch to use | master | 
| terraform_github_folder | Subfolder within GitHub repository for Terraform | |
| terraform_github_token | GitHub access token for the repo defined in terraform_github_repo | |
| cloudwatch_namespace | AWS CloudWatch metric namespace where metrics should be shipped | |
| tmp_folder | Temporary folder to use | /tmp | 
| log_group_name | CloudWatch log group name that the container will emit logs to | |
| region | AWS Region for resources | |
| account_id | AWS account ID | |
| cluster_id | The cluster on which to run the scheduled ECS task | |
| cron_expression | Cron scheduling expression in form cron(x x x x x x) | 
module "drifter_estate" {
  source                 = "git::https://github.com/digirati-labs/terraform-drifter.git//"
  slack_webhook_url      = "${var.slack_webhook_status}"
  terraform_identifier   = "my-terraform-repo-master"
  terraform_s3_bucket    = "my-state-bucket"
  terraform_github_repo  = "my-github-user/my-terraform-repo"
  terraform_github_token = "${data.aws_ssm_parameter.terraform_github_token.value}"
  cloudwatch_namespace   = "terraform-drift"
  log_group_name         = "${var.log_group_name}"
  prefix                 = "${var.prefix}"
  region                 = "${var.region}"
  account_id             = "${var.account_id}"
  cluster_id             = "${module.metropolis_cluster.cluster_id}"
  cron_expression        = "cron(0 0 * * ? *)"
}