Add MongoDB resource type and Kubernetes Terraform recipe (#21)

- mongodb.yaml schema
- Terraform recipe (main.tf, variables.tf, outputs.tf)
- README.md with usage instructions and manual testing notes

Signed-off-by: Panagiotis Bellias <belliaspan@gmail.com>

Author: panagiotisbellias

recipes/kubernetes/mongodb/README.md

@@ -2,38 +2,92 @@
 
 This recipe provisions a MongoDB instance on Kubernetes using Terraform.
 
+---
+
 ## Inputs
 
-- `name` (string, required): MongoDB instance name
-- `version` (string, default: 6.0): MongoDB version
-- `replicas` (int, default: 1): Number of replicas
-- `storage_size` (string, default: 10Gi): PVC size
-- `storage_class` (string, default: standard): Storage class
-- `username` (string, default: admin): Admin username
-- `password` (string, required): Admin password
-- `persistence` (bool, default: true): Enable persistence
-- `backup_enabled` (bool, default: false): Enable backups
-- `backup_schedule` (string): Cron schedule for backups
-- `resources` (object): CPU/memory requests/limits
+| Variable           | Type   | Default      | Description                        |
+|-------------------|--------|-------------|------------------------------------|
+| `name`             | string | required    | MongoDB instance name              |
+| `version`          | string | 6.0         | MongoDB version                    |
+| `replicas`         | int    | 1           | Number of replicas                 |
+| `storage_size`     | string | 10Gi        | PVC size                           |
+| `storage_class`    | string | standard    | Kubernetes storage class           |
+| `username`         | string | admin       | Admin username                     |
+| `password`         | string | required    | Admin password                     |
+| `persistence`      | bool   | true        | Enable persistence                 |
+| `backup_enabled`   | bool   | false       | Enable backups                     |
+| `backup_schedule`  | string | ""         | Cron schedule for backups          |
+| `resources`        | object | {}          | CPU/memory requests and limits     |
+
+> **Note:** For CI or ephemeral testing, `persistence` should be set to `false` to avoid PVC-related delays in Kind clusters.
+
+---
 
 ## Outputs
 
 - `mongodb_service_name`: Kubernetes service name
 - `mongodb_credentials_secret`: Secret containing credentials
 
+---
+
 ## Manual Testing
 
 1. Apply Terraform:
    ```bash
    terraform init
-   terraform apply -var="name=mydb" -var="password=MySecretPass123"
+   terraform apply \
+        -var="name=mydb" \
+        -var="password=MySecretPass123" \
+        -auto-approve
    ```
 
-2. Connect to MongoDB:
+2. Check pod status:
+   ```bash
+   kubectl get pods
+   # Ensure test-mongodb-0 is READY=1/1
+   ```
+
+3. Connect to MongoDB:
    ```bash
    kubectl run mongo-client --rm -it --image=mongo -- \
         mongo "mongodb://$(kubectl get svc mydb-svc -o jsonpath='{.spec.clusterIP}'):27017" \
         -u admin -p MySecretPass123
    ```
 
-3. Verify database operations.
+4. Verify database operations.
+
+5. Clean up (optional):
+   ```bash
+   terraform destroy -var="name=mydb" -var="password=MySecretPass123" -auto-approve
+   ```
+
+---
+
+## CI / GitHub Actions Testing
+
+This recipe is automatically tested in GitHub Actions for pull requests and branch pushes.
+
+- A temporary Kind cluster is created.
+- Terraform applies the recipe with `persistence=false` for fast ephemeral testing.
+- The workflow waits for MongoDB pods to become ready.
+- Terraform destroys the resources and deletes the Kind cluster after the test.
+
+Workflow file: `.github/workflows/test-mongodb-recipe.yml`
+
+Example ephemeral test run:
+```bash
+terraform apply -var="name=test-mongodb" -var="password=MySecretPass123" -var="persistence=false" -auto-approve
+kubectl get pods
+terraform destroy -var="name=test-mongodb" -var="password=MySecretPass123" -var="persistence=false" -auto-approve
+```
+
+> Make sure the MongoDB pod shows `READY=1/1` before connecting.
+
+---
+
+## References
+
+- Radius MongoDB Resource Schema: https://docs.radapp.io/reference/resource-schema/databases/mongodb/
+- Example Kubernetes Recipe: https://github.com/radius-project/recipes/blob/main/local-dev/mongodatabases.bicep
+