MongoDB Service Template

A Backstage Software Template for provisioning MongoDB database instances using Crossplane.

Overview

This template creates the necessary Crossplane resources to provision a MongoDB database instance in your Kubernetes cluster. It includes:

• XRD (Composite Resource Definition): Defines the MongoDB API
• Composition: Implements the MongoDB provisioning logic
• Example Claim: Shows how to request a MongoDB instance

Features

• 🚀 Self-Service Provisioning: Developers can provision MongoDB instances through Backstage
• ⚙️ Configurable Storage: Choose storage size from 1GB to 100GB
• 🔧 Automatic DNS: Creates DNS records for database access
• 📊 Status Tracking: Connection strings available in resource status

Prerequisites

Crossplane Installation

Ensure Crossplane is installed in your cluster:

kubectl create namespace crossplane-system
helm repo add crossplane-stable https://charts.crossplane.io/stable
helm install crossplane --namespace crossplane-system crossplane-stable/crossplane

Required Providers

This template requires the following Crossplane providers:

1. Provider NOP (for simulation/testing):

kubectl apply -f - <<EOF
apiVersion: pkg.crossplane.io/v1
kind: Provider
metadata:
  name: provider-nop
spec:
  package: xpkg.upbound.io/crossplane-contrib/provider-nop:v0.2.0
EOF

Required Functions

Install the necessary Crossplane composition functions:

kubectl apply -f - <<EOF
apiVersion: pkg.crossplane.io/v1beta1
kind: Function
metadata:
  name: function-go-templating
spec:
  package: xpkg.upbound.io/crossplane-contrib/function-go-templating:v0.10.0
---
apiVersion: pkg.crossplane.io/v1beta1
kind: Function
metadata:
  name: function-auto-ready
spec:
  package: xpkg.upbound.io/crossplane-contrib/function-auto-ready:v0.2.1
---
apiVersion: pkg.crossplane.io/v1beta1
kind: Function
metadata:
  name: function-sequencer
spec:
  package: xpkg.upbound.io/crossplane-contrib/function-sequencer:v0.3.0
---
apiVersion: pkg.crossplane.io/v1beta1
kind: Function
metadata:
  name: function-environment-configs
spec:
  package: xpkg.upbound.io/crossplane-contrib/function-environment-configs:v0.1.0
EOF

Usage

Through Backstage

1. Navigate to the Software Catalog
2. Click "Create Component"
3. Select "MongoDB Database"
4. Fill in the required parameters:
   • Instance Name: Unique identifier for your MongoDB instance
   • Namespace: Kubernetes namespace (default: default)
   • Storage Size: Size in GB (1-100)
   • Owner: Team or user who owns this resource

Manual Deployment

1. Apply the XRD:

kubectl apply -f content/definition.yaml

2. Apply the Composition:

kubectl apply -f content/composition.yaml

3. Create a claim:

kubectl apply -f content/example.yaml

Parameters

Parameter	Description	Type	Default	Required
name	Instance name	string	-	Yes
namespace	Kubernetes namespace	string	default	No
storageSize	Storage size in GB	integer	10	No
owner	Resource owner	string	group:platform	No

Architecture

The template creates a composite resource that provisions:

1. Cluster Resource: A simulated compute cluster for MongoDB
2. DNS Record: Automatic DNS entry for database access
3. ConfigMap: Stores configuration values
4. NOP Resource: Simulates database provisioning delay (30s)

Connection String

After provisioning, the connection string is available in the resource status:

kubectl get mongodb <instance-name> -n <namespace> -o jsonpath='{.status.connString}'

Format: mongodb+srv://<username>:<password>@<fqdn>/<database>

Development

Testing Locally

1. Clone this repository
2. Install the template in Backstage:

catalog:
  locations:
    - type: url
      target: https://github.com/open-service-portal/service-mongodb-template/blob/main/template.yaml

Customization

To customize the MongoDB provisioning:

1. Edit content/definition.yaml to add parameters
2. Modify content/composition.yaml to change provisioning logic
3. Update template.yaml to expose new parameters in Backstage

Troubleshooting

Common Issues

MongoDB stuck in Creating state

• Check if all required functions are installed
• Verify the NOP provider is running: kubectl get providers

Connection string not appearing

• Ensure DNS record creation succeeded
• Check composition logs: kubectl describe composition mongodb

Permission denied errors

• Verify Crossplane has necessary RBAC permissions
• Check ServiceAccount bindings

Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Submit a pull request

License

MIT License - see LICENSE file for details

Support

For issues and questions:

• GitHub Issues: open-service-portal/service-mongodb-template
• Discussions: open-service-portal/discussions