Terraform to enable vpc flow logs to amazon s3

Question

I am working on terraform script to automate aws resource creation. As part of that I am creating a vpc and trying to enable vpc flow logs for that. I have created an s3 bucket and also created an iam role as mentioned in the terraform docs https://www.terraform.io/docs/providers/aws/r/flow_log.html

My terraform code is given below

data "aws_s3_bucket" "selected" {
  bucket = "${var.s3_bucket_name}"
}

resource "aws_flow_log" "vpc_flow_log" {
    count = "${var.enable_vpc_flow_log}"
    iam_role_arn    = "${aws_iam_role.test_role.arn}"
    log_destination      = "${data.aws_s3_bucket.selected.arn}"
    log_destination_type = "s3"
    traffic_type         = "ALL"
    vpc_id               = "${var.vpc_id}"

}

resource "aws_iam_role" "test_role" {
  name = "example"
  count = "${var.enable_vpc_flow_log}"
  assume_role_policy = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "",
      "Effect": "Allow",
      "Principal": {
        "Service": "vpc-flow-logs.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}
EOF
}
resource "aws_iam_role_policy" "example" {
  name = "example"
  count = "${var.enable_vpc_flow_log}"
  role = "${aws_iam_role.test_role.id}"
  policy = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": [
        "logs:CreateLogGroup",
        "logs:CreateLogStream",
        "logs:PutLogEvents",
        "logs:DescribeLogGroups",
        "logs:DescribeLogStreams"
      ],
      "Effect": "Allow",
      "Resource": "*"
    }
  ]
}
EOF
}

When I execute terraform plan am getting the following error

Error: module.enable_vpc_flow_log.aws_flow_log.vpc_flow_log: "log_group_name": required field is not set

Error: module.enable_vpc_flow_log.aws_flow_log.vpc_flow_log: : invalid or unknown key: log_destination

Error: module.enable_vpc_flow_log.aws_flow_log.vpc_flow_log: : invalid or unknown key: log_destination_type

According to the terraform documentation log_group_name is optional and we have to specify its value only if we are selecting cloud_watch_logs as the log_destination_type

Can anyone help me to resolve my error and to enable the vpc flow logs to s3.

Answer 1

I have updated my terraform version from 0.11.8 to 0.11.10. I am now able to configure the vpc flow logs to s3 without any errors using the below resource block.

resource "aws_flow_log" "vpc_flow_log" {
    log_destination      = "${var.s3_bucket_arn}"
    log_destination_type = "s3"
    traffic_type         = "ALL"
    vpc_id               = "${var.vpc_id}"
}