How to enable IF condition on terrafrom modules - amazon-web-services

Question

I need to create TF CloudWatch Metrices only of the env is QAT and PROD. Currently using TF modules to create those in all env.
module "aws_cloudwatch_log_metric_filter" {
source = "https://github.com/modules.git//aws-cloudwatch-log-metric-filter"
log_group_name = "/aws/lambda/${var.lambda_name}"
pattern = "{$.message = \"---------------- Message ----------------\"}"
}
locals {
base_tags = {
environment = var.environment
}
}
Main resource where I am calling module.
resource "aws_cloudwatch_log_metric_filter" "log_metric" {
count = var.count
name = "Metric"
pattern = var.pattern
log_group_name = var.log_group_name
metric_transformation {
name = "name"
namespace = "namespace"
value = "1"
default_value = "0"
}
}

Answer 1

You could do this in the module:
resource "aws_cloudwatch_log_metric_filter" "log_metric" {
count = var.environment == "QAT" || var.environment == "PROD" ? 1 : 0
name = "Metric"
pattern = var.pattern
log_group_name = "${var.environment}-${var.log_group_name}"
metric_transformation {
name = "name"
namespace = "namespace"
value = "1"
default_value = "0"
}
}
The log_group_name = "${var.environment}-${var.log_group_name}" will ensure you don't get issues with the same log group name.

Answer 2

A simple but good solution :
locals {
cw_env = ["QUA", "PROD"]
}
resource "aws_cloudwatch_log_metric_filter" "log_metric" {
count = contains(local.cw_env, var.env) ? 1 : 0
name = "Metric"
pattern = var.pattern
log_group_name = var.log_group_name
metric_transformation {
name = "name"
namespace = "namespace"
value = "1"
default_value = "0"
}
}
Note you can also use it at the above level :
module "aws_cloudwatch_log_metric_filter" {
source = "https://github.com/modules.git//aws-cloudwatch-log-metric-filter"
count = contains(local.cw_env, local.base_tags.environment) ? 1 : 0
log_group_name = "/aws/lambda/${var.lambda_name}"
pattern = "{$.message = \"---------------- Message ----------------\"}"
}
locals {
base_tags = {
environment = var.environment
}
cw_env = ["QUA", "PROD"]
}