Email Operator for Kubernetes

Overview

The Email Operator for Kubernetes is a custom controller that manages email sending operations within a Kubernetes cluster. It utilizes the Kopf framework and integrates with email service providers like Mailersend to facilitate email dispatch directly from Kubernetes resources.

Features

• Custom Resource Definitions (CRDs) for Email and EmailSenderConfig
• Secure management of email provider credentials using Kubernetes Secrets
• Extensible architecture supporting multiple email service providers
• Full lifecycle management of email resources
• Event logging and status updates for email operations

Prerequisites

• Kubernetes cluster (tested with v1.24+)
• Helm 3
• Docker
• Python 3.9+
• MailerSend account and API token

Setting up MailerSend

1. Create a MailerSend account at https://mailersend.com

2. Generate an API token from the MailerSend dashboard:

   • Go to Settings → API Tokens
   • Click "Create New Token"
   • Give it a name and ensure it has "Email Send" permission
   • Copy the generated token

3. Base64 encode your API token:

   echo -n "your-api-token-here" | base64

4. Update the values.yaml with your encoded token:

   providers:
     - name: mailersend
       apiToken: <your-base64-encoded-token>
       senderEmail: your-verified-sender@domain.com

   Note: Make sure your sender email is verified in MailerSend dashboard.

Installation

Using Helm

1. Clone the repository:

   git clone https://github.com/teddy0605/emailsender-operator.git
   cd email-operator

2. Configure your email provider credentials in values.yaml

3. Install the Helm chart:

   helm install email-operator ./chart/emailsender-operator

Manual Installation

1. Build the Docker image:

   make build

2. Push the image to your registry:

   make push

3. Deploy the operator:

   make install

Usage

1. Create an EmailSenderConfig resource:

   apiVersion: teddy.io/v1
   kind: EmailSenderConfig
   metadata:
     name: my-email-config
   spec:
     apiTokenSecretRef: my-email-secret
     senderEmail: sender@example.com

2. Create an Email resource:

   apiVersion: teddy.io/v1
   kind: Email
   metadata:
     name: test-email
   spec:
     senderConfigRef: my-email-config
     recipientEmail: recipient@example.com
     subject: "Test Email"
     body: "This is a test email sent via the Kubernetes Email Operator."

Configuration

Refer to the values.yaml file in the Helm chart for configurable parameters. Key parameters include:

• image.repository: Docker image repository
• image.tag: Docker image tag
• resources: CPU/Memory resource requests and limits
• providers: Email provider configurations

Development

To run the operator locally for development:

make run

To stop the local development process:

make stop

Roadmap / TODO

Future improvements planned for this project:

1. Observability

   • Add Prometheus metrics for monitoring email operations
   • Implement health check endpoints
   • Enhanced logging and tracing

2. Reliability

   • Add rate limiting for email sending
   • Implement retry mechanism with exponential backoff
   • Add circuit breaker for provider failures

3. Security

   • Implement proper API token rotation
   • Add support for multiple authentication methods
   • Enhanced secret management

4. Features

   • Support for HTML emails
   • Email templates
   • Attachment support
   • Multiple recipient support

5. Testing

   • Add unit tests
   • Add integration tests
   • Add E2E tests

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Support

If you encounter any issues or have questions, please file an issue on GitHub.