Add the Github workflow for the Terraform checks

Signed-off-by: gatici <[email protected]>

.github/workflows/terraform.yaml

@@ -0,0 +1,15 @@
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+name: Check Terraform Module
+
+on:
+  pull_request:
+    paths:
+      - '**.tf'
+
+jobs:
+  check-terraform-module:
+    name: Check Terraform Module
+    uses: canonical/data-platform-workflows/.github/workflows/terraform.yaml@main
+    secrets: inherit

terraform/README.md

@@ -1,70 +1,54 @@
-# Mongodb-k8s Terraform Module
+# MongoDB Operator Terraform module
 
-This mongodb-k8s Terraform module aims to deploy the [mongodb-k8s charm](https://charmhub.io/mongodb-k8s?channel=6/edge) via Terraform.
+This folder contains a base [Terraform][Terraform] module for the `mongodb-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 such as Juju model name, channel or application name and 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 Mongodb-k8s charm using Terraform
+## Using mongodb-k8s base module in higher level modules
 
-Make sure that `storage` plugin is enabled for Microk8s:
+If you want to use `mongodb-operator` base module as part of your Terraform module, import it like shown below.
 
-```console
-sudo microk8s enable hostpath-storage
-```
-
-Add a Juju model:
-
-```console
-juju add model <model-name>
-```
-
-Initialise the provider:
-
-```console
-terraform init
-```
-
-Customize the configuration inputs under `terraform.tfvars` file according to requirement.
+```text
+module "mongodb-operator" {
+  source = "git::https://github.com/canonical/mongodb-operator.git//terraform"
+  
+  model_name = "juju_model_name"
+  
+ (Customize configuration variables here if needed)
 
-Replace the values in the `terraform.tfvars` file:
-
-```yaml
-# Mandatory Config Options
-model_name = "put your model-name here"
-```
-
-Run Terraform Plan by providing var-file:
-
-```console
-terraform plan -var-file="terraform.tfvars" 
+}
 ```
 
-Deploy the resources, skip the approval:
+Create the integrations, for instance:
 
-```console
-terraform apply -auto-approve 
-```
-
-### Check the Output
+```text
+resource "juju_integration" "amf-db" {
+  model = var.model_name
 
-Run `juju switch <juju model>` to switch to the target Juju model and observe the status of the application.
+  application {
+    name     = module.amf.app_name
+    endpoint = module.amf.database_endpoint
+  }
 
-```console
-juju status
+  application {
+    name     = module.mongodb.app_name
+    endpoint = module.mongodb.database_endpoint
+  }
+}
 ```
 
-### Clean up
+Please check the available [integration pairs][integration pairs].
 
-Remove the application:
-
-```console
-terraform destroy -auto-approve
-```
+[Terraform]: https://www.terraform.io/
+[Juju]: https://juju.is
+[Terraform Juju provider]: https://registry.terraform.io/providers/juju/juju/latest
+[integration pairs]: https://charmhub.io/mongodb-k8s/integrations?channel=6/edge

terraform/main.tf

@@ -1,13 +1,16 @@
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
 resource "juju_application" "mongodb-k8s" {
-  name  = "mongodb-k8s"
+  name  = var.app_name
   model = var.model_name
 
   charm {
     name    = "mongodb-k8s"
     channel = var.channel
     base    = "[email protected]"
   }
-  config = var.mongo-config
+  config = var.config
   units  = 1
   trust  = true
 }

terraform/outputs.tf

@@ -1,4 +1,51 @@
-output "db_application_name" {
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+output "app_name" {
   description = "Name of the deployed application."
   value       = juju_application.mongodb-k8s.name
+}
+
+# Provided integration endpoints
+
+output "database_endpoint" {
+  description = "Name of the endpoint to provide the mongodb_client interface."
+  value       = "database"
+}
+
+output "obsolete_endpoint" {
+  description = "Name of the endpoint to provide the mongodb interface."
+  value       = "obsolete"
+}
+
+output "cos_agent_endpoint" {
+  description = "Name of the endpoint to provide the cos_agent interface."
+  value       = "cos-agent"
+}
+
+output "config_server_endpoint" {
+  description = "Name of the endpoint to provide the shards interface."
+  value       = "config-server"
+}
+
+output "cluster_endpoint" {
+  description = "Name of the endpoint to provide the config-server interface."
+  value       = "cluster"
+}
+
+# Required integration endpoints
+
+output "certificates_endpoint" {
+  description = "Name of the endpoint to provide the tls-certificates interface."
+  value       = "certificates"
+}
+
+output "s3_credentials_endpoint" {
+  description = "Name of the endpoint to provide the s3 interface."
+  value       = "s3-credentials"
+}
+
+output "sharding_endpoint" {
+  description = "Name of the endpoint to provide the shards interface."
+  value       = "sharding"
 }

terraform/terraform.tf

@@ -1,4 +1,4 @@
-# Copyright 2023 Canonical Ltd.
+# Copyright 2024 Canonical Ltd.
 # See LICENSE file for licensing details.
 
 terraform {

terraform/variables.tf

@@ -1,16 +1,26 @@
+# 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
+  default     = "mongodb"
+}
+
 variable "channel" {
-  description = "The channel to use when deploying a charm "
+  description = "The channel to use when deploying a charm"
   type        = string
   default     = "6/beta"
 }
 
-variable "mongo-config" {
-  description = "Additional configuration for the MongoDB"
+variable "config" {
+  description = "Additional configuration for the MongoDB. Details about available options can be found at https://charmhub.io/mongodb-k8s/configure?channel=6/edge."
+  type        = map(string)
   default     = {}
 }