Metric filter patter with variables-CodePudding

I am trying to define a metric filter for my vpc flow logs and wanted the pattern to formed by a data source result. I have defined a data source to return all enis of given subnets and I want to loop over the result set and construct one metric filter for those enis. but the for_each is creating a metric filter for each eni. I can't figure out a way to adjust the code such that I can write something like (interfaceid=$value1 || interfaceid=$value2 || ...) in the filter pattern. any help will be much appreciated.

data "aws_network_interfaces" "ENI_List" {
  filter {
    name = "subnet-id"
    values = ["subnet-A", "subnet-B", "subnet-C"]
  }
}

Below is my metric filter. I want to be able to use each eni in the data.aws_network_interfaces.ENI_List.ids result set in my pattern like below

resource "aws_cloudwatch_log_metric_filter" "EUN_Network_Filter" {
  for_each            = toset("${data.aws_network_interfaces.ENI_List.ids}")
  name                = "EUN_DC_Network_Traffic_Monitoring"
  pattern             = "[version, accountid, (interfaceid=${each.value}), srcaddr, dstaddr, srcport, dstport, protocol, packets, bytes, start, end, action, logstatus=NODATA]"
  log_group_name      = "VPC_Flow_Log_Group" # "${data.aws_cloudwatch_log_group.vpc_flow_log_group}"

  metric_transformation {
    name      = "EUN_Network"
    namespace = "EUN_Network_Traffic"
    value     = "1"
  }
}

CodePudding user response：

Well, you could create the following local value with combination of formatlist and join:

locals {
  interfaceids_str = join(" || ", formatlist("interfaceid=%s", var.enis))
}

then

 resource "aws_cloudwatch_log_metric_filter" "EUN_Network_Filter" {
  name                = "EUN_DC_Network_Traffic_Monitoring"
  pattern             = "[version, accountid, (${local.interfaceids_str}), srcaddr, dstaddr, srcport, dstport, protocol, packets, bytes, start, end, action, logstatus=NODATA]"
  log_group_name      = "VPC_Flow_Log_Group" # "${data.aws_cloudwatch_log_group.vpc_flow_log_group}"

  metric_transformation {
    name      = "EUN_Network"
    namespace = "EUN_Network_Traffic"
    value     = "1"
  }
}