use custom service for monitoring to support multi-region (#1171)

basic_service does not allow multi-region service support

---------

Signed-off-by: Kenny Leung <[email protected]>

Author: k4leung4

modules/slo/README.md

@@ -19,7 +19,7 @@ No modules.
 |------|------|
 | [google_monitoring_alert_policy.slo_burn_rate_multi_region](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/monitoring_alert_policy) | resource |
 | [google_monitoring_alert_policy.slo_burn_rate_per_region](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/monitoring_alert_policy) | resource |
-| [google_monitoring_service.this](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/monitoring_service) | resource |
+| [google_monitoring_custom_service.this](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/monitoring_custom_service) | resource |
 | [google_monitoring_slo.availability](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/monitoring_slo) | resource |
 | [google_monitoring_slo.availability_per_region](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/monitoring_slo) | resource |
 
@@ -32,7 +32,7 @@ No modules.
 | <a name="input_regions"></a> [regions](#input\_regions) | A list of regions that the cloudrun service is deployed in. | `list(string)` | n/a | yes |
 | <a name="input_service_name"></a> [service\_name](#input\_service\_name) | Name of service to setup SLO for. | `string` | n/a | yes |
 | <a name="input_service_type"></a> [service\_type](#input\_service\_type) | Type of service to setup SLO for. | `string` | `"CLOUD_RUN"` | no |
-| <a name="input_slo"></a> [slo](#input\_slo) | Configuration for setting up SLO | <pre>object({<br/>    enable          = optional(bool, false)<br/>    enable_alerting = optional(bool, false)<br/>    availability = optional(object(<br/>      {<br/>        multi_region_goal = optional(number, 0.999)<br/>        per_region_goal   = optional(number, 0.999)<br/>      }<br/>    ), null)<br/>  })</pre> | `{}` | no |
+| <a name="input_slo"></a> [slo](#input\_slo) | Configuration for setting up SLO | <pre>object({<br/>    enable          = optional(bool, false)<br/>    enable_alerting = optional(bool, false)<br/>    availability = optional(object(<br/>      {<br/>        multi_region_goal = optional(number, 0.999)<br/>        per_region_goal   = optional(number, 0.999)<br/>      }<br/>    ), {})<br/>  })</pre> | `{}` | no |
 
 ## Outputs
 

modules/slo/main.tf

@@ -2,23 +2,14 @@ locals {
   region_filter = "one_of(${join(", ", formatlist("%q", var.regions))})"
 }
 
-resource "google_monitoring_service" "this" {
+resource "google_monitoring_custom_service" "this" {
   service_id = "${lower(var.service_type)}-${lower(var.service_name)}"
   project    = var.project_id
-
-  basic_service {
-    service_type = var.service_type
-    service_labels = {
-      service_name = var.service_name
-    }
-  }
 }
 
 # SLO with availability SLI across all regions
 resource "google_monitoring_slo" "availability" {
-  count = var.slo.availability != null ? 1 : 0
-
-  service      = google_monitoring_service.this.service_id
+  service      = google_monitoring_custom_service.this.service_id
   slo_id       = "${var.service_name}-availability-multi-region"
   display_name = "${var.service_name} - Multi-region Availability SLO"
   project      = var.project_id
@@ -34,7 +25,7 @@ resource "google_monitoring_slo" "availability" {
 resource "google_monitoring_slo" "availability_per_region" {
   for_each = var.slo.availability != null ? toset(var.regions) : []
 
-  service      = google_monitoring_service.this.service_id
+  service      = google_monitoring_custom_service.this.service_id
   slo_id       = "${var.service_name}-availability-${each.value}"
   display_name = "${var.service_name} - ${each.value} Availability SLO"
   project      = var.project_id
@@ -60,7 +51,7 @@ resource "google_monitoring_alert_policy" "slo_burn_rate_multi_region" {
 
     condition_threshold {
       filter = <<-EOT
-        select_slo_burn_rate("${google_monitoring_slo.availability[0].id}", 3600)
+        select_slo_burn_rate("${google_monitoring_slo.availability.id}", 3600)
       EOT
 
       duration        = "0s"

modules/slo/variables.tf

@@ -29,7 +29,7 @@ variable "slo" {
         multi_region_goal = optional(number, 0.999)
         per_region_goal   = optional(number, 0.999)
       }
-    ), null)
+    ), {})
   })
   default = {}
 }