Building Plone Microservices with Python & Docker

Plone is a powerful CMS built on Python. Microservices make it more scalable. Docker helps deploy them easily. This guide shows you how.

Why Use Microservices with Plone?

Microservices break apps into small, independent parts. This improves scalability and maintenance. Plone benefits from this architecture.

Each microservice handles one function. For example, user auth or content rendering. This matches well with Plone's modular design.

Docker containers package these services. They run the same way everywhere. This solves deployment headaches.

Setting Up Your Environment

First, install Docker and Python 3.8+. Verify they work:

docker --version
python --version

Create a project folder. Add these files:

• Dockerfile - Container setup
• requirements.txt - Python dependencies
• app.py - Your Plone service

Creating a Basic Plone Microservice

Start with a simple REST endpoint. Use plone.restapi for the API layer. See our REST API guide for more details.

Here's a basic service:

from plone.restapi.services import Service
from plone import api

class HelloService(Service):
    def reply(self):
        portal = api.portal.get()
        return {
            "message": f"Hello from {portal.title}",
            "url": portal.absolute_url()
        }

This returns portal info as JSON. Register it in ZCML:

<configure xmlns="http://namespaces.zope.org/zope">
    <service
        method="GET"
        for="*"
        factory=".services.HelloService"
        name="@hello"
        permission="zope2.View" />
</configure>

Dockerizing the Service

Create a Dockerfile:

FROM plone/plone-backend:6.0.0
COPY . /app
RUN pip install -r /app/requirements.txt

Build and run it:

docker build -t plone-microservice .
docker run -p 8080:8080 plone-microservice

Your service now runs in isolation. Scale it by running multiple containers.

Connecting Multiple Services

Use Docker Compose for multi-service setups. Here's a docker-compose.yml example:

version: '3'
services:
  plone:
    image: plone-microservice
    ports:
      - "8080:8080"
  redis:
    image: redis
  celery:
    build: .
    command: celery -A myapp worker
    depends_on:
      - redis

This adds Redis and Celery for async tasks.

Best Practices

Follow these tips for production:

• Use environment variables for config
• Implement health checks
• Add logging to stdout
• Follow testing best practices

Here's a health check example:

@app.route('/health')
def health():
    return {"status": "OK"}, 200

Scaling Considerations

For large deployments, consider:

• Load balancing between containers
• Database scaling with ZEO and RelStorage
• Caching strategies

Conclusion

Plone works well with microservices. Docker makes deployment simple. Start small and scale as needed.

Use the patterns shown here. Combine them with Plone's strengths. You'll build robust, scalable applications.