chore: Refactor the Terraform module to follow spec CC006

terraform/README.md

@@ -16,18 +16,22 @@ rather serve as a building block for higher level modules.
 - **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-pcf-k8s base module in higher level modules
 
 If you want to use `sdcore-pcf-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 "pcf" {
   source = "git::https://github.com/canonical/sdcore-pcf-k8s-operator//terraform"
   
-  model_name = "juju_model_name"
+  model = juju_model.my_model.name
 }
 ```
 
@@ -38,11 +42,11 @@ resource "juju_integration" "pcf-nrf" {
   model = var.model_name
   application {
     name     = module.pcf.app_name
-    endpoint = module.pcf.fiveg_nrf_endpoint
+    endpoint = module.pcf.requires.fiveg_nrf
   }
   application {
     name     = module.nrf.app_name
-    endpoint = module.nrf.fiveg_nrf_endpoint
+    endpoint = module.nrf.provides.fiveg_nrf
   }
 }
 ```

terraform/main.tf

@@ -3,13 +3,17 @@
 
 resource "juju_application" "pcf" {
   name  = var.app_name
-  model = var.model_name
+  model = var.model
 
   charm {
-    name    = "sdcore-pcf-k8s"
-    channel = var.channel
+    name     = "sdcore-pcf-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

@@ -6,31 +6,17 @@ output "app_name" {
   value       = juju_application.pcf.name
 }
 
-# Required integration endpoints
-
-output "fiveg_nrf_endpoint" {
-  description = "Name of the endpoint used to integrate with the NRF."
-  value       = "fiveg_nrf"
-}
-
-output "certificates_endpoint" {
-  description = "Name of the endpoint used to integrate with the TLS certificates provider."
-  value       = "certificates"
+output "requires" {
+  value = {
+    fiveg_nrf     = "fiveg_nrf"
+    certificates  = "certificates"
+    logging       = "logging"
+    sdcore_config = "sdcore_config"
+  }
 }
 
-output "logging_endpoint" {
-  description = "Name of the endpoint used to integrate with the Logging provider."
-  value       = "logging"
+output "provides" {
+  value = {
+    metrics = "metrics-endpoint"
+  }
 }
-
-output "sdcore_config_endpoint" {
-  description = "Name of the endpoint used to integrate with the NMS."
-  value       = "sdcore_config"
-}
-
-# Provided integration endpoints
-
-output "metrics_endpoint" {
-  description = "Exposes the Prometheus metrics endpoint providing telemetry about the PCF instance."
-  value       = "metrics-endpoint"
-}

terraform/variables.tf

@@ -1,12 +1,6 @@
 # Copyright 2024 Canonical Ltd.
 # See LICENSE file for licensing details.
 
-variable "model_name" {
-  description = "Name of Juju model to deploy application to."
-  type        = string
-  default     = ""
-}
-
 variable "app_name" {
   description = "Name of the application in the Juju model."
   type        = string
@@ -18,3 +12,45 @@ variable "channel" {
   type        = string
   default     = "1.5/edge"
 }
+
+variable "config" {
+  description = "Application config. Details about available options can be found at https://charmhub.io/sdcore-pcf-k8s-operator/configure."
+  type        = map(string)
+  default     = {}
+}
+
+variable "constraints" {
+  description = "Juju constraints to apply for this application."
+  type        = string
+  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-pcf-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."
+  }
+
+}