fix: Added functionality to simply specify the database version numbe…

…r ins… (#388)

Co-authored-by: Bharath KKB <bharathkrishnakb@gmail.com>

modules/postgresql/main.tf

@@ -49,7 +49,7 @@ resource "google_sql_database_instance" "default" {
   provider            = google-beta
   project             = var.project_id
   name                = local.master_instance_name
-  database_version    = var.database_version
+  database_version    = can(regex("\\d", substr(var.database_version, 0, 1))) ? format("POSTGRES_%s", var.database_version) : replace(var.database_version, substr(var.database_version, 0, 8), "POSTGRES")
   region              = var.region
   encryption_key_name = var.encryption_key_name
   deletion_protection = var.deletion_protection

modules/postgresql/variables.tf

@@ -34,6 +34,11 @@ variable "random_instance_name" {
 variable "database_version" {
   description = "The database version to use"
   type        = string
+
+  validation {
+    condition     = (length(var.database_version) >= 9 && ((upper(substr(var.database_version, 0, 9)) == "POSTGRES_") && can(regex("^\\d+(?:_?\\d)*$", substr(var.database_version, 9, -1))))) || can(regex("^\\d+(?:_?\\d)*$", var.database_version))
+    error_message = "The specified database version is not a valid representaion of database version. Valid database versions should be like the following patterns:- \"9_6\", \"postgres_9_6\" or \"POSTGRES_14\"."
+  }
 }
 
 // required