Merged in MON-289-monitors-for-nginx (pull request #133)

MON-289 add dropped connections monitor

Approved-by: Quentin Manfroi <quentin.manfroi@yahoo.fr>
Approved-by: Alexandre Gaillet <alexandre.gaillet@fr.clara.net>
Approved-by: Jérôme Respaut <shr3ps@gmail.com>
Approved-by: Jean-Philippe LAINÉ <jean-philippe.laine@fr.clara.net>

middleware/nginx/README.md

@@ -16,6 +16,7 @@ module "datadog-monitors-middleware-nginx" {
 
 Creates DataDog monitors with the following checks:
 
+- Nginx dropped connections
 - Nginx vhost status does not respond
 
 ## Inputs
@@ -33,11 +34,18 @@ Creates DataDog monitors with the following checks:
 | nginx_connect_message | Custom message for Nginx status monitor | string | `` | no |
 | nginx_connect_silenced | Groups to mute for Nginx status monitor | map | `<map>` | no |
 | nginx_connect_threshold_critical | Nginx status monitor (critical threshold) | string | `1.1754943508222875e-38` | no |
+| nginx_dropped_extra_tags | Extra tags for Nginx dropped connections monitor | list | `<list>` | no |
+| nginx_dropped_message | Custom message for Nginx dropped connections monitor | string | `` | no |
+| nginx_dropped_silenced | Groups to mute for Nginx dropped connections monitor | map | `<map>` | no |
+| nginx_dropped_threshold_critical | Nginx dropped connections critical threshold | string | `0` | no |
+| nginx_dropped_time_aggregator | Monitor aggregator for Nginx dropped connections [available values: min, max or avg] | string | `min` | no |
+| nginx_dropped_timeframe | Monitor timeframe for Nginx dropped connections [available values: `last_#m` (1, 5, 10, 15, or 30), `last_#h` (1, 2, or 4), or `last_1d`] | string | `last_5m` | no |
 
 ## Outputs
 
 | Name | Description |
 |------|-------------|
+| datadog_nginx_dropped_connections_id | id for monitor datadog_nginx_dropped_connections |
 | datadog_nginx_process_id | id for monitor datadog_nginx_process |
 
 ## Related documentation

middleware/nginx/inputs.tf

@@ -60,3 +60,38 @@ variable "nginx_connect_threshold_critical" {
   type        = "string"
   default     = "1.1754943508222875e-38"
 }
+
+variable "nginx_dropped_silenced" {
+  description = "Groups to mute for Nginx dropped connections monitor"
+  type        = "map"
+  default     = {}
+}
+
+variable "nginx_dropped_extra_tags" {
+  description = "Extra tags for Nginx dropped connections monitor"
+  type        = "list"
+  default     = []
+}
+
+variable "nginx_dropped_message" {
+  description = "Custom message for Nginx dropped connections monitor"
+  type        = "string"
+  default     = ""
+}
+
+variable "nginx_dropped_time_aggregator" {
+  description = "Monitor aggregator for Nginx dropped connections [available values: min, max or avg]"
+  type        = "string"
+  default     = "min"
+}
+
+variable "nginx_dropped_timeframe" {
+  description = "Monitor timeframe for Nginx dropped connections [available values: `last_#m` (1, 5, 10, 15, or 30), `last_#h` (1, 2, or 4), or `last_1d`]"
+  type        = "string"
+  default     = "last_5m"
+}
+
+variable "nginx_dropped_threshold_critical" {
+  description = "Nginx dropped connections critical threshold"
+  default     = 0
+}

middleware/nginx/monitors-nginx.tf

@@ -27,3 +27,29 @@ resource "datadog_monitor" "datadog_nginx_process" {
 
   tags = ["env:${var.environment}", "type:middleware", "provider:nginx", "resource:nginx", "team:claranet", "created-by:terraform", "${var.nginx_connect_extra_tags}"]
 }
+
+resource "datadog_monitor" "datadog_nginx_dropped_connections" {
+  name    = "[${var.environment}] Nginx dropped connections {{#is_alert}}{{{comparator}}} {{threshold}} ({{value}}){{/is_alert}}{{#is_warning}}{{{comparator}}} {{warn_threshold}} ({{value}}){{/is_warning}}"
+  message = "${coalesce(var.nginx_dropped_message, var.message)}"
+
+  type = "metric alert"
+
+  query = "${var.nginx_dropped_time_aggregator}(${var.nginx_dropped_timeframe}):avg:nginx.net.conn_dropped_per_s${module.filter-tags.query_alert} by {host} > ${var.nginx_dropped_threshold_critical}"
+
+  thresholds {
+    critical = "${var.nginx_dropped_threshold_critical}"
+  }
+
+  notify_no_data      = false
+  evaluation_delay    = "${var.evaluation_delay}"
+  new_host_delay      = "${var.new_host_delay}"
+  notify_audit        = false
+  timeout_h           = 0
+  include_tags        = true
+  locked              = false
+  require_full_window = true
+
+  silenced = "${var.nginx_dropped_silenced}"
+
+  tags = ["env:${var.environment}", "type:middleware", "provider:nginx", "resource:nginx", "team:claranet", "created-by:terraform", "${var.nginx_dropped_extra_tags}"]
+}

middleware/nginx/outputs.tf

@@ -2,3 +2,8 @@ output "datadog_nginx_process_id" {
   description = "id for monitor datadog_nginx_process"
   value       = "${datadog_monitor.datadog_nginx_process.*.id}"
 }
+
+output "datadog_nginx_dropped_connections_id" {
+  description = "id for monitor datadog_nginx_dropped_connections"
+  value       = "${datadog_monitor.datadog_nginx_dropped_connections.*.id}"
+}