Error with aws_iam_policy

[Webgardener]

│ Error: error creating Synthetics Canary: ValidationException: 1 validation error detected: Value 'arn:aws:iam:::policy/service-role/synthetic_policy_development' at 'executionRoleArn' failed to satisfy constraint: Member must satisfy regular expression pattern: arn:(aws[a-zA-Z-]*)?:iam::\d{12}:role/?[a-zA-Z_0-9+=,.@\-_/]+
│ 
│   with synthetics_canary.api,
│   on monitoring.tf line 111, in resource "synthetics_canary" "api":
│  111: resource "synthetics_canary" "api" {
│ 

How to reproduce?

resource "aws_iam_policy" "synthetic" {
  name        = "synthetic_policy_${var.environment}"
  path        = "/service-role/"
  description = "CloudWatch Synthetics lambda execution role for running canaries"
policy = [..]
}

resource "synthetics_canary" "api" {
  name                      = "api-${var.environment}"
  runtime_version      = var.synthetic_runtime_version
  execution_role_arn   = aws_iam_policy.synthetic.arn
  artifact_s3_location = "s3://${aws_s3_bucket.synthetic.id}/canary/${var.region}/${var.environment}"
  zip_file             = data.archive_file.synthetic.output_path
  handler              = "apiCanaryBlueprint.handler"
  run_config {
    memory_in_mb       = 1024
    timeout_in_seconds = 60
  }
  schedule {
    expression = "rate(60 minutes)"
  }
}

[Webgardener]

I actually made it work:

resource "aws_iam_role" "synthetic" {
  name = "synthetic_role_${var.environment}"

  assume_role_policy = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": "sts:AssumeRole",
      "Principal": {
        "Service": "lambda.amazonaws.com"
      },
      "Effect": "Allow",
      "Sid": ""
    }
  ]
}
EOF
}


resource "aws_iam_role_policy_attachment" "synthetic-attach" {
  role       = aws_iam_role.synthetic.name
  policy_arn = aws_iam_policy.synthetic.arn
}


resource "synthetics_canary" "api" {
  name                      = "api-${var.environment}"
  runtime_version      = var.synthetic_runtime_version
  execution_role_arn   = aws_iam_role.synthetic.arn
  artifact_s3_location = "s3://${aws_s3_bucket.synthetic.id}/canary/${var.region}/${var.environment}"
  zip_file             = data.archive_file.synthetic.output_path
  handler              = "apiCanaryBlueprint.handler"
  run_config {
    memory_in_mb       = 1024
    timeout_in_seconds = 60
  }
  schedule {
    expression = "rate(60 minutes)"
  }
}