chore: Updating Terraform module (#57)

terraform/README.md

@@ -1,73 +1,55 @@
-# SD-Core PCF K8s Terraform Module
+# SD-Core PCF K8s Terraform module
 
-This SD-Core PCF K8s Terraform module aims to deploy the [sdcore-pcf-k8s charm](https://charmhub.io/sdcore-pcf-k8s) via Terraform.
+This folder contains a base [Terraform][Terraform] module for the sdcore-pcf-k8s charm.
 
-## Getting Started
+The module uses the [Terraform Juju provider][Terraform Juju provider] to model the charm
+deployment onto any Kubernetes environment managed by [Juju][Juju].
 
-### Prerequisites
+The base module is not intended to be deployed in separation (it is possible though), but should
+rather serve as a building block for higher level modules.
 
-The following software and tools needs to be installed and should be running in the local environment.
+## Module structure
 
-- `microk8s`
-- `juju 3.x`
-- `terrafom`
+- **main.tf** - Defines the Juju application to be deployed.
+- **variables.tf** - Allows customization of the deployment. Except for exposing the deployment
+  options (Juju model name, channel or application name) also models the charm configuration.
+- **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.
 
-### Deploy the sdcore-pcf-k8s charm using Terraform
+## Using sdcore-pcf-k8s base module in higher level modules
 
-Make sure that `storage` plugin is enabled for Microk8s:
+If you want to use `sdcore-pcf-k8s` base module as part of your Terraform module, import it
+like shown below:
 
-```console
-sudo microk8s enable hostpath-storage
+```text
+module "pcf" {
+  source = "git::https://github.com/canonical/sdcore-pcf-k8s-operator//terraform"
+  
+  model_name = "juju_model_name"
+}
 ```
 
-Add a Juju model:
+Create integrations, for instance:
 
-```console
-juju add model <model-name>
+```text
+resource "juju_integration" "pcf-nrf" {
+  model = var.model_name
+  application {
+    name     = module.pcf.app_name
+    endpoint = module.pcf.fiveg_nrf_endpoint
+  }
+  application {
+    name     = module.nrf.app_name
+    endpoint = module.nrf.fiveg_nrf_endpoint
+  }
+}
 ```
 
-Initialise the provider:
+The complete list of available integrations can be found [here][pcf-integrations].
 
-```console
-terraform init
-```
-
-Customize the configuration inputs under `terraform.tfvars` file according to requirement.
-
-Replace the values in the `terraform.tfvars` file:
-
-```yaml
-# Mandatory Config Options
-model_name             = "put your model-name here"
-db_application_name    = "put your MongoDB app name here"
-certs_application_name = "put your Self Signed Certificates app name here"
-nrf_application_name   = "put your NRF app name here"
-```
-
-Create the Terraform Plan:
-
-```console
-terraform plan -var-file="terraform.tfvars" 
-```
-
-Deploy the resources:
-
-```console
-terraform apply -auto-approve 
-```
-
-### Check the Output
-
-Run `juju switch <juju model>` to switch to the target Juju model and observe the status of the applications.
-
-```console
-juju status --relations
-```
-
-### Clean up
-
-Destroy the deployment:
-
-```console
-terraform destroy -auto-approve
-```
+[Terraform]: https://www.terraform.io/
+[Terraform Juju provider]: https://registry.terraform.io/providers/juju/juju/latest
+[Juju]: https://juju.is
+[pcf-integrations]: https://charmhub.io/sdcore-pcf-k8s/integrations

terraform/main.tf

@@ -1,5 +1,8 @@
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
 resource "juju_application" "pcf" {
-  name  = "pcf"
+  name  = var.app_name
   model = var.model_name
 
   charm {
@@ -10,46 +13,3 @@ resource "juju_application" "pcf" {
   units = 1
   trust = true
 }
-
-resource "juju_integration" "pcf-db" {
-  model = var.model_name
-
-  application {
-    name     = juju_application.pcf.name
-    endpoint = "database"
-  }
-
-  application {
-    name     = var.db_application_name
-    endpoint = "database"
-  }
-}
-
-resource "juju_integration" "pcf-certs" {
-  model = var.model_name
-
-  application {
-    name     = juju_application.pcf.name
-    endpoint = "certificates"
-  }
-
-  application {
-    name     = var.certs_application_name
-    endpoint = "certificates"
-  }
-}
-
-resource "juju_integration" "pcf-nrf" {
-  model = var.model_name
-
-  application {
-    name     = juju_application.pcf.name
-    endpoint = "fiveg_nrf"
-  }
-
-  application {
-    name     = var.nrf_application_name
-    endpoint = "fiveg-nrf"
-  }
-}
-

terraform/outputs.tf

@@ -1,4 +1,24 @@
-output "pcf_application_name" {
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+output "app_name" {
   description = "Name of the deployed application."
   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 "database_endpoint" {
+  description = "Name of the endpoint used to integrate with the database."
+  value = "database"
+}
+
+output "certificates_endpoint" {
+  description = "Name of the endpoint used to integrate with the TLS certificates provider."
+  value = "certificates"
+}

terraform/variables.tf

@@ -1,29 +1,20 @@
+# 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 "channel" {
-  description = "The channel to use when deploying a charm."
-  type        = string
-  default     = "1.3/edge"
-}
-
-variable "db_application_name" {
-  description = "The name of the application providing the `database` endpoint."
+variable "app_name" {
+  description = "Name of the application in the Juju model."
   type        = string
-  default     = ""
+  default     = "pcf"
 }
 
-variable "certs_application_name" {
-  description = "Name of the application providing the `certificates` integration endpoint."
+variable "channel" {
+  description = "The channel to use when deploying a charm."
   type        = string
-  default     = ""
+  default     = "1.3/edge"
 }
-
-variable "nrf_application_name" {
-  description = "The name of the application providing the `fiveg_nrf` endpoint."
-  type        = string
-  default     = ""
-}