terraform.aws-baseline-infra/modules/ManagementGovernance/Monitoring.ALB/main.tf

locals {
  alb-name = "app/${split("/", var.load-balancer)[2]}/${split("/", var.load-balancer)[3]}"
}

resource "aws_cloudwatch_metric_alarm" "alb-HTTPCode_ELB_5XX_Count" {
  alarm_name                = "${var.settings.HTTPCode_ELB_5XX_Count.ecccode}-ALB_${local.alb-name}-HTTPCode_ELB_5XX_Count"
  comparison_operator       = var.settings.HTTPCode_ELB_5XX_Count.comparison_operator
  evaluation_periods        = var.settings.HTTPCode_ELB_5XX_Count.evaluation_periods
  metric_name               = "HTTPCode_ELB_5XX_Count"
  period                    = var.settings.HTTPCode_ELB_5XX_Count.period
  statistic                 = var.settings.HTTPCode_ELB_5XX_Count.statistic
  threshold                 = var.settings.HTTPCode_ELB_5XX_Count.threshold
  alarm_description         = "ALB:HTTPCode_ELB_5XX_Count"
  namespace                 = "AWS/ApplicationELB"
  insufficient_data_actions = []
  actions_enabled           = var.actions-enabled
  alarm_actions             = [var.settings.HTTPCode_ELB_5XX_Count.action]
  ok_actions                = [var.settings.HTTPCode_ELB_5XX_Count.action]
  dimensions = {
    LoadBalancer = local.alb-name
  }
}

resource "aws_cloudwatch_metric_alarm" "alb-TargetConnectionErrorCount" {
  alarm_name                = "${var.settings.TargetConnectionErrorCount.ecccode}-ALB_${local.alb-name}-TargetConnectionErrorCount"
  comparison_operator       = var.settings.TargetConnectionErrorCount.comparison_operator
  evaluation_periods        = var.settings.TargetConnectionErrorCount.evaluation_periods
  metric_name               = "TargetConnectionErrorCount"
  period                    = var.settings.TargetConnectionErrorCount.period
  statistic                 = var.settings.TargetConnectionErrorCount.statistic
  threshold                 = var.settings.TargetConnectionErrorCount.threshold
  alarm_description         = "ALB:TargetConnectionErrorCount"
  namespace                 = "AWS/ApplicationELB"
  insufficient_data_actions = []
  actions_enabled           = var.actions-enabled
  alarm_actions             = [var.settings.TargetConnectionErrorCount.action]
  ok_actions                = [var.settings.TargetConnectionErrorCount.action]
  dimensions = {
    LoadBalancer = local.alb-name
  }
}

resource "aws_cloudwatch_metric_alarm" "alb-TargetResponseTime" {
  alarm_name                = "${var.settings.TargetResponseTime.ecccode}-ALB_${local.alb-name}-TargetResponseTime"
  comparison_operator       = var.settings.TargetResponseTime.comparison_operator
  evaluation_periods        = var.settings.TargetResponseTime.evaluation_periods
  metric_name               = "TargetResponseTime"
  period                    = var.settings.TargetResponseTime.period
  statistic                 = var.settings.TargetResponseTime.statistic
  threshold                 = var.settings.TargetResponseTime.threshold
  alarm_description         = "ALB:TargetResponseTime"
  namespace                 = "AWS/ApplicationELB"
  insufficient_data_actions = []
  actions_enabled           = var.actions-enabled
  alarm_actions             = [var.settings.TargetResponseTime.action]
  ok_actions                = [var.settings.TargetResponseTime.action]
  dimensions = {
    LoadBalancer = local.alb-name
  }
}

/*
module "alb-targetgroups" {
  source        = "../../util/resource-list"
  resource-type = "alb-targetgroups"
  query-input   = var.load-balancer
  asrolearn     = var.asrolearn
}
*/
// causes Rate exceeded error, maybe because of adaptive AWS_RETRY_MODE?

/*
module "alb_tgs" {
  assume_role_arn   = var.asrolearn
  role_session_name = "terraform-resource-list"
  source            = "../../util/terraform-aws-cli"
  aws_cli_commands  = ["elbv2", "describe-target-groups", "--load-balancer-arn", var.load-balancer]
  aws_cli_query     = "TargetGroups[*].TargetGroupArn"
}
*/

module alb_tgs {
  source = "../../util/awscli"
  access_key       = var.target-account-ak
  aws_cli_commands = "elbv2 describe-target-groups --load-balancer-arn ${var.load-balancer} --query TargetGroups[*].TargetGroupArn"
  secret_key       = var.target-account-sk
  session_token    = var.target-account-token
}

resource "aws_cloudwatch_metric_alarm" "alb-HealthyHostCount" {
  # for_each                  = module.alb-targetgroups.result-set
  for_each                  = toset(module.alb_tgs.awscliout)
  alarm_name                = "${var.settings.HealthHostCountMin.ecccode}-ALBTG_:${split(":", each.value)[5]}-HealthyHostCount"
  comparison_operator       = var.settings.HealthHostCountMin.comparison_operator
  evaluation_periods        = var.settings.HealthHostCountMin.evaluation_periods
  metric_name               = "HealthyHostCount"
  period                    = var.settings.HealthHostCountMin.period
  statistic                 = var.settings.HealthHostCountMin.statistic
  threshold                 = var.settings.HealthHostCountMin.threshold
  alarm_description         = "ALBTG:HealthyHostCount"
  namespace                 = "AWS/ApplicationELB"
  insufficient_data_actions = []
  actions_enabled           = var.actions-enabled
  alarm_actions             = [var.settings.HealthHostCountMin.action]
  ok_actions                = [var.settings.HealthHostCountMin.action]
  dimensions = {
    TargetGroup  = split(":", each.value)[5]
    LoadBalancer = "app/${split("/", var.load-balancer)[2]}/${split("/", var.load-balancer)[3]}"
  }
}