feat: add `available_cpu` variable

Add `available_cpu` variable for specifying the number of CPUs to allocate to
the Cloud Function.

Add validation checks for the variables `available_cpu`, `available_memory_mb`
and `timeout`.

Closes #14

README.md

@@ -149,7 +149,8 @@ environment variable.
 | <a name="input_alert_notification_channels"></a> [alert\_notification\_channels](#input\_alert\_notification\_channels) | A list of notification channel IDs to send alerts to. The format for the channel IDs should<br>    be as follows.<br><br>    [<br>      "projects/[PROJECT\_ID]/notificationChannels/[CHANNEL\_ID]"<br>    ] | `list(string)` | `[]` | no |
 | <a name="input_alert_success_period"></a> [alert\_success\_period](#input\_alert\_success\_period) | Period over which 'alert\_success\_threshold' is used. Default: "3600s" which<br>is one hour. | `string` | `"3600s"` | no |
 | <a name="input_alert_success_threshold"></a> [alert\_success\_threshold](#input\_alert\_success\_threshold) | The minimum number of successes within 'alert\_success\_period' below which an<br>alert is fired. | `number` | `5` | no |
-| <a name="input_available_memory_mb"></a> [available\_memory\_mb](#input\_available\_memory\_mb) | Maxiumum memory available to the script in MiB. Default: 128 MiB. | `number` | `128` | no |
+| <a name="input_available_cpu"></a> [available\_cpu](#input\_available\_cpu) | Maxiumum number of CPUs available to the script. See<br>https://cloud.google.com/functions/docs/configuring/memory for valid<br>values.<br><br>When this value is set, `available_memory_mb` must also be specified.<br>Otherwise, the default is based on the value of `available_memory_mb`. | `number` | n/a | yes |
+| <a name="input_available_memory_mb"></a> [available\_memory\_mb](#input\_available\_memory\_mb) | Maxiumum memory available to the script in MiB. See<br>https://cloud.google.com/functions/docs/configuring/memory for valid<br>values. Default: 128 MiB. | `number` | `128` | no |
 | <a name="input_description"></a> [description](#input\_description) | Longer human-friendly description of the script | `string` | `""` | no |
 | <a name="input_enable_versioning"></a> [enable\_versioning](#input\_enable\_versioning) | The bucket's versioning configuration.<br>While set to true, versioning is fully enabled for the bucket. | `bool` | `true` | no |
 | <a name="input_entry_point"></a> [entry\_point](#input\_entry\_point) | Entrypoint to script. Defaults to 'main'. | `string` | `"main"` | no |

main.tf

@@ -137,6 +137,7 @@ resource "google_cloudfunctions2_function" "script" {
   service_config {
     timeout_seconds       = var.timeout
     service_account_email = local.service_account_email
+    available_cpu         = var.available_cpu
     available_memory      = "${var.available_memory_mb}Mi"
     max_instance_count    = 1
 

variables.tf

@@ -90,14 +90,54 @@ variable "timeout" {
     Maximum time, in seconds, that a script can take to execute. Invocations
     which take longer than this fail. Default: 120 seconds.
   EOT
+
+  validation {
+    condition     = var.timeout > 0 && var.timeout <= 3600
+    error_message = "The `timeout` value must be > 0 and <= 3600 seconds."
+  }
+}
+
+variable "available_cpu" {
+  type        = number
+  description = <<-EOT
+    Maxiumum number of CPUs available to the script. See
+    https://cloud.google.com/functions/docs/configuring/memory for valid
+    values.
+
+    When this value is set, `available_memory_mb` must also be specified.
+    Otherwise, the default is based on the value of `available_memory_mb`.
+  EOT
+
+  validation {
+    condition = contains(
+      [0.083, 0.167, 0.333, 0.583, 1, 2, 4, 8], var.available_cpu
+    )
+    error_message = <<-EOT
+      The `available_cpu` value must be valid. See
+      https://cloud.google.com/functions/docs/configuring/memory
+    EOT
+  }
 }
 
 variable "available_memory_mb" {
   type        = number
   default     = 128
   description = <<-EOT
-    Maxiumum memory available to the script in MiB. Default: 128 MiB.
+    Maxiumum memory available to the script in MiB. See
+    https://cloud.google.com/functions/docs/configuring/memory for valid
+    values. Default: 128 MiB.
   EOT
+
+  validation {
+    condition = contains(
+      [128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768],
+      var.available_memory_mb
+    )
+    error_message = <<-EOT
+      The `available_memory_mb` value must be valid. See
+      https://cloud.google.com/functions/docs/configuring/memory
+    EOT
+  }
 }
 
 variable "alert_email_addresses" {