feat: implemented alerting for expiring certificates for application gateway

infrastructure/tf-core/availability_test.tf

@@ -0,0 +1,30 @@
+locals {
+  avail = var.availability_test
+}
+
+module "azurerm_application_insights_standard_availability_test" {
+  for_each = { for key, val in var.regions : key => val if val.is_primary_region && var.features.alerts_enabled && local.avail != null }
+
+  source                  = "../../../dtos-devops-templates/infrastructure/modules/application-insights-availability-test"
+  name                    = "${module.regions_config[each.key].names.function-app}-${var.availability_test.name_suffix}"
+  resource_group_name     = data.azurerm_application_insights.ai.resource_group_name
+  location                = each.key
+  action_group_id         = var.features.alerts_enabled ? module.monitor_action_group_performance[0].monitor_action_group.id : null
+  application_insights_id = data.azurerm_application_insights.ai.id
+
+  target_url = var.availability_test.target_url
+
+  timeout   = var.availability_test.timeout
+  frequency = var.availability_test.frequency
+
+  headers = {
+    OCP-Apim-Subscription-Key = var.OCP_APIM_SUBSCRIPTION_KEY
+  }
+
+  ssl_validation = {
+    expected_status_code        = var.availability_test.ssl_validation.expected_status_code
+    ssl_cert_remaining_lifetime = var.availability_test.ssl_validation.ssl_cert_remaining_lifetime
+  }
+
+  alert = var.availability_test.alert
+}

infrastructure/tf-core/environments/development.tfvars

@@ -20,6 +20,11 @@ tags = {
   Environment = "development"
 }
 
+availability_test = {
+  name_suffix = "retrieve-cohort-request-audit-webtest"
+  target_url  = "https://api.non-live.nationalscreening.nhs.uk/dev-uks-retrieve-cohort-request-audit/health"
+}
+
 regions = {
   uksouth = {
     is_primary_region = true

infrastructure/tf-core/environments/production.tfvars

@@ -20,6 +20,11 @@ tags = {
   Environment = "production"
 }
 
+availability_test = {
+  name_suffix = "retrieve-cohort-request-audit-webtest"
+  target_url  = "https://api.nationalscreening.nhs.uk/prod-uks-retrieve-cohort-request-audit/health"
+}
+
 regions = {
   uksouth = {
     is_primary_region = true

infrastructure/tf-core/environments/sandbox.tfvars

@@ -19,6 +19,11 @@ tags = {
   Environment = "sandbox"
 }
 
+availability_test = {
+  name_suffix = "retrieve-cohort-request-audit-webtest"
+  target_url  = "https://api.non-live.nationalscreening.nhs.uk/dev-uks-retrieve-cohort-request-audit/health"
+}
+
 regions = {
   uksouth = {
     is_primary_region = true
@@ -667,7 +672,7 @@ function_apps = {
         }
       ]
       env_vars_static = {
-        AcceptableLatencyThresholdMs = "500"
+        AcceptableLatencyThresholdMs  = "500"
         RetrieveSupersededRecordsLast = "true"
       }
     }
@@ -864,7 +869,7 @@ function_apps = {
       ]
       env_vars_static = {
         AcceptableLatencyThresholdMs = "500"
-        MaxRetryCount=3
+        MaxRetryCount                = 3
       }
     }
 

infrastructure/tf-core/variables.tf

@@ -58,6 +58,13 @@ variable "TARGET_SUBSCRIPTION_ID" {
   type        = string
 }
 
+variable "OCP_APIM_SUBSCRIPTION_KEY" {
+  description = "API Management subscription key"
+  type        = string
+  sensitive   = true
+  default     = null
+}
+
 variable "application" {
   description = "Project/Application code for deployment"
   type        = string
@@ -93,6 +100,32 @@ variable "features" {
   type        = map(bool)
 }
 
+variable "availability_test" {
+  description = "Configuration for the Application Insights Standard Web Test"
+  type = object({
+    name_suffix = string
+    target_url  = string
+
+    frequency = optional(number, 900)
+    timeout   = optional(number, 30)
+
+    ssl_validation = optional(object({
+      enabled                     = optional(bool, true)
+      expected_status_code        = optional(number, 200)
+      ssl_cert_remaining_lifetime = optional(number, 30)
+    }), {})
+
+    alert = optional(object({
+      description   = optional(string, "Endpoint Availability & Certificate Expiry Monitoring")
+      frequency     = optional(string, "PT1H")
+      window_size   = optional(string, "P1D")
+      auto_mitigate = optional(bool, false)
+    }), {})
+  })
+
+  default = null
+}
+
 variable "regions" {
   type = map(object({
     address_space     = optional(string)