chore: Refactor the Terraform module to follow spec CC006

terraform/README.md

@@ -11,16 +11,20 @@ The base module is not intended to be deployed in separation (it is possible tho
 - **main.tf** - Defines the Juju application to be deployed.
 - **variables.tf** - Allows customization of the deployment options (Juju model name, channel or application name).
 - **output.tf** - Responsible for integrating the module with other Terraform modules, primarily by defining potential integration endpoints (charm integrations), but also by exposing the application name.
-- **terraform.tf** - Defines the Terraform provider.
+- **versions.tf** - Defines the Terraform provider.
 
 ## Using sdcore-nrf-k8s base module in higher level modules
 
 If you want to use `sdcore-nrf-k8s` base module as part of your Terraform module, import it like shown below.
 
 ```text
+data "juju_model" "my_model" {
+  name = "my_model_name"
+}
+
 module "sdcore-nrf-k8s" {
   source                 = "git::https://github.com/canonical/sdcore-nrf-k8s-operator//terraform"
-  model_name             = "juju_model_name"  
+  model = juju_model.my_model.name
   # Optional Configurations
   # channel                        = "put the Charm channel here" 
   # app_name                       = "put the application name here" 
@@ -35,12 +39,12 @@ resource "juju_integration" "nrf-db" {
 
   application {
     name     = module.nrf.app_name
-    endpoint = module.nrf.database_endpoint
+    endpoint = module.nrf.requires.database
   }
 
   application {
     name     = module.mongodb.app_name
-    endpoint = module.mongodb.database_endpoint
+    endpoint = module.mongodb.provides.database
   }
 }
 ```

terraform/main.tf

@@ -1,16 +1,21 @@
 # Copyright 2024 Canonical Ltd.
 # See LICENSE file for licensing details.
 
-resource "juju_application" "sdcore-nrf-k8s" {
+resource "juju_application" "nrf" {
   name  = var.app_name
-  model = var.model_name
+  model = var.model
 
   charm {
-    name    = "sdcore-nrf-k8s"
-    channel = var.channel
+    name     = "sdcore-nrf-k8s"
+    channel  = var.channel
+    revision = var.revision
   }
-  units = 1
-  trust = true
+
+  config      = var.config
+  constraints = var.constraints
+  units       = var.units
+  resources   = var.resources
+  trust       = true
 }
 
 

terraform/outputs.tf

@@ -3,39 +3,22 @@
 
 output "app_name" {
   description = "Name of the deployed application."
-  value       = juju_application.sdcore-nrf-k8s.name
+  value       = juju_application.nrf.name
 }
 
-# Required integration endpoints
 
-output "database_endpoint" {
-  description = "Name of the endpoint to integrate with MongoDB using mongodb_client interface."
-  value       = "database"
+output "requires" {
+  value = {
+    database      = "database"
+    certificates  = "certificates"
+    sdcore_config = "sdcore_config"
+    logging       = "logging"
+  }
 }
 
-output "certificates_endpoint" {
-  description = "Name of the endpoint to get the X.509 certificate using tls-certificates interface."
-  value       = "certificates"
+output "provides" {
+  value = {
+    fiveg_nrf = "fiveg_nrf"
+    metrics   = "metrics-endpoint"
+  }
 }
-
-output "sdcore_config_endpoint" {
-  description = "Name of the endpoint used to integrate with the NMS."
-  value       = "sdcore_config"
-}
-
-output "logging_endpoint" {
-  description = "Name of the endpoint used to integrate with the Logging provider."
-  value       = "logging"
-}
-
-# Provided integration endpoints
-
-output "fiveg_nrf_endpoint" {
-  description = "Name of the endpoint to provide fiveg_nrf interface."
-  value       = "fiveg_nrf"
-}
-
-output "metrics_endpoint" {
-  description = "Exposes the Prometheus metrics endpoint providing telemetry about the NRF instance."
-  value       = "metrics-endpoint"
-}

terraform/variables.tf

@@ -1,10 +1,10 @@
 # Copyright 2024 Canonical Ltd.
 # See LICENSE file for licensing details.
 
-variable "model_name" {
-  description = "Name of Juju model to deploy application to."
+variable "app_name" {
+  description = "Name of the application in the Juju model"
   type        = string
-  default     = ""
+  default     = "nrf"
 }
 
 variable "channel" {
@@ -13,8 +13,44 @@ variable "channel" {
   default     = "1.5/edge"
 }
 
-variable "app_name" {
-  description = "Name of the application in the Juju model"
+variable "config" {
+  description = "Application config. Details about available options can be found at https://charmhub.io/sdcore-nrf-k8s-operator/configure."
+  type        = map(string)
+  default     = {}
+}
+
+variable "constraints" {
+  description = "Juju constraints to apply for this application."
   type        = string
-  default     = "nrf"
-}
+  default     = ""
+}
+
+variable "model" {
+  description = "Reference to a `juju_model`."
+  type        = string
+  default     = ""
+}
+
+variable "resources" {
+  description = "Resources to use with the application. Details about available options can be found at https://charmhub.io/sdcore-nrf-k8s-operator/configure."
+  type        = map(string)
+  default     = {}
+}
+
+variable "revision" {
+  description = "Revision number of the charm"
+  type        = number
+  default     = null
+}
+
+variable "units" {
+  description = "Number of units to deploy"
+  type        = number
+  default     = 1
+
+  validation {
+    condition     = var.units == 1
+    error_message = "Scaling is not supported for this charm."
+  }
+
+}