feat: support alb_5xx_rate (#3)

main.tf

@@ -114,7 +114,7 @@ resource "aws_cloudwatch_event_target" "monitoring_jump_start_connection" {
 {
  "Type": "monitoring-jump-start-tf-connection",
  "Module": "alb",
- "Version": "1.0.0",
+ "Version": "1.1.0",
  "Partition": "${data.aws_partition.current.partition}",
  "AccountId": "${data.aws_caller_identity.current.account_id}",
  "Region": "${data.aws_region.current.name}"
@@ -191,6 +191,58 @@ resource "aws_cloudwatch_metric_alarm" "alb_5xx_count_too_high_anomaly_detection
  }
 }
 
+resource "aws_cloudwatch_metric_alarm" "alb_5xx_rate_too_high" {
+ depends_on = [aws_sns_topic_subscription.marbot]
+ count = (var.alb_5xx_rate == "static" && var.enabled) ? 1 : 0
+
+ alarm_name = "marbot-alb-5xx-rate-too-high-${random_id.id8.hex}"
+ alarm_description = "5XX responses relativ to request from ALB too high. (created by marbot)"
+ evaluation_periods = var.alb_5xx_rate_evaluation_periods
+ comparison_operator = "GreaterThanThreshold"
+ threshold = var.alb_5xx_rate_threshold
+ alarm_actions = [local.topic_arn]
+ ok_actions = [local.topic_arn]
+ treat_missing_data = "notBreaching"
+ tags = var.tags
+
+ metric_query {
+ id = "alb5xx" # must start with [a-z]
+ return_data = "false"
+ metric {
+ metric_name = "HTTPCode_ELB_5XX_Count"
+ namespace = "AWS/ApplicationELB"
+ period = var.alb_5xx_rate_period
+ stat = "Sum"
+
+ dimensions = {
+ LoadBalancer = var.loadbalancer_fullname
+ }
+ }
+ }
+
+ metric_query {
+ id = "requests"
+ return_data = "false"
+ metric {
+ metric_name = "RequestCount"
+ namespace = "AWS/ApplicationELB"
+ period = var.alb_5xx_rate_period
+ stat = "Sum"
+
+ dimensions = {
+ LoadBalancer = var.loadbalancer_fullname
+ }
+ }
+ }
+
+ metric_query {
+ id = "rate"
+ expression = "IF(requests<10, 0, alb5xx/requests)"
+ label = "5XX rate"
+ return_data = "true"
+ }
+}
+
 resource "aws_cloudwatch_metric_alarm" "alb_rejected_connection_count_too_high" {
  depends_on = [aws_sns_topic_subscription.marbot]
  count = (var.alb_rejected_connection_count == "static" && var.enabled) ? 1 : 0

variables.tf

@@ -72,6 +72,32 @@ variable "alb_5xx_count_evaluation_periods" {
 
 
 
+variable "alb_5xx_rate" {
+ type = string
+ description = "5XX responses from the ALB relativ to requests (static|off)."
+ default = "off"
+}
+
+variable "alb_5xx_rate_threshold" {
+ type = number
+ description = "The maximum rate (in %) of 5XX responses from the ALB (0-100)."
+ default = 5
+}
+
+variable "alb_5xx_rate_period" {
+ type = number
+ description = "The period in seconds over which the specified statistic is applied (<= 86400 and multiple of 60)."
+ default = 300
+}
+
+variable "alb_5xx_rate_evaluation_periods" {
+ type = number
+ description = "The number of periods over which data is compared to the specified threshold (>= 1 and $period*$evaluation_periods <= 86400)."
+ default = 1
+}
+
+
+
 variable "alb_rejected_connection_count" {
  type = string
  description = "Rejected connections because the ALB had reached its maximum number of connections (static|off)."