"While I am using terraform to create vpc flow log module to s3 bucket then its throwing errors like: An argument named "flow_log_destination_type" is not expected here. An argument named "flow_log_destination_arn" is not expected here. In the Terraform docs, I can see the details to be filled like log_destination_type & log_destination_arn, and I found some docs on GitHub that exactly says the same code but while trying it's not working for me
The following error produced:
Error: Unsupported argument
on main.tf line 52, in module "vpc_with_flow_logs_s3_bucket":
52: flow_log_destination_type = "s3"
An argument named "flow_log_destination_type" is not expected here.
Error: Unsupported argument
on main.tf line 53, in module "vpc_with_flow_logs_s3_bucket":
53: flow_log_destination_arn = "${aws_s3_bucket.terra-test2-lifecycle.arn}"
An argument named "flow_log_destination_arn" is not expected here.
Error: Unsupported argument
on main.tf line 55, in module "vpc_with_flow_logs_s3_bucket":
55: vpc_flow_log_tags = {
An argument named "vpc_flow_log_tags" is not expected here.
Where I am doing wrong?"
module "vpc" {
source = "terraform-aws-modules/vpc/aws"
version = "2.33.0"
# Interpolated from the workspace
name = "${terraform.workspace}"
cidr = var.vpc_cidr
azs = var.vpc_azs
private_subnets = var.vpc_private_subnets
public_subnets = var.vpc_public_subnets
enable_nat_gateway = var.vpc_enable_nat_gw
single_nat_gateway = var.vpc_single_nat_gw
public_subnet_tags = {
Name = "${terraform.workspace}-public"
}
private_subnet_tags = {
Name = "${terraform.workspace}-private"
}
tags = {
Name = "${terraform.workspace}"
}
vpc_tags = {
owner = "PEDevOps"
environment = "${terraform.workspace}"
version = "0.0.1"
managedby = "Terraform"
}
}
module "vpc_with_flow_logs_s3_bucket" {
source = "../../"
log_destination_type = "s3"
log_destination_arn = "${aws_s3_bucket.terra-test2-lifecycle.arn}"
vpc_flow_log_tags = {
Name = "vpc-flow-logs-s3-bucket"
}
}
resource "aws_s3_bucket" "terra-test-lifecycle" {
bucket = "terra-test-lifecycle"
acl = "private"
lifecycle_rule {
id = "log"
enabled = true
prefix = "log/"
tags = {
"rule" = "log"
"autoclean" = "true"
}
transition {
days = 30
storage_class = "STANDARD_IA" # or "ONEZONE_IA"
}
expiration {
days = 60
}
}
lifecycle_rule {
id = "tmp"
prefix = "tmp/"
enabled = true
expiration {
date = "2020-06-06"
}
}
}
Why does terraform fail with "An argument named "flow_log_destination_type" is not expected here"?
The module at "../../" does not declare any of the log_destination_type, log_destination_arn, or vpc_flow_log_tags variables and Terraform considers it an error to assign to undeclared variables in a module block like this:
module "vpc_with_flow_logs_s3_bucket" {
source = "../../"
log_destination_type = "s3"
log_destination_arn = "${flow_log_destination_arn}"
vpc_flow_log_tags = {
Name = "vpc-flow-logs-s3-bucket"
}
}
It's most likely that "../../" is the wrong source path for the vpc_with_flow_logs_s3_bucket module and you should fix that. If you are in the source path for the module where this module block is declared and you run cd ../../, do you end up in the directory with the vpc_with_flow_logs_s3_bucket Terraform code? If not, then source is set incorrectly and you need to fix it.
If "../../" is the correct path, then you should add the missing variable declarations.
variable "log_destination_type" {
type = string
}
variable "log_destination_arb" {
type = string
}
variable "vpc_flow_log_tags" {
type = map(string)
}
This error occurs if you are passing a variable that module is not expecting.
For e.g.
module "vpc_with_flow_logs_s3_bucket" {
source = "../../"
log_destination_type = "s3"
log_destination_arn = "${flow_log_destination_arn}"
vpc_flow_log_tags = {
Name = "vpc-flow-logs-s3-bucket"
}
}
If you specify this it will throw an error if the variable flow_log_destination_arn is defined in main.tf and not in variables.tf
source: ../../vpc_with_flow_logs_s3_bucket/main.tf
resource "aws_flow_log" "example" {
iam_role_arn = "${aws_iam_role.example.arn}"
log_destination = "${aws_cloudwatch_log_group.example.arn}"
traffic_type = "ALL"
vpc_id = "${aws_vpc.example.id}"
}
I'll share another possible reason to this error.
Writing configuration block like this:
scaling_config = {
desired_size = 2
max_size = 2
min_size = 2
}
Instead of (Notice the = Equal Sign):
scaling_config {
desired_size = 2
max_size = 2
min_size = 2
}
Will give an error of An argument named "scaling_config" is not expected here.
(*) Notice that after the change, if the block type is really not supported the error title will be change from:
Error: Unsupported argument
To:
Error: Unsupported block type
With error message of:
Blocks of type "scaling_config" are not expected here.