Infrastructure as Code: Dockerizing Apps with Zene

Writing Dockerfiles and docker-compose configurations is repetitive but error-prone. One wrong instruction, and your container fails to start. Zene understands the nuances of containerization and can automate this process.

In this example, we ask Zene to containerize a simple Flask application.

The Task

task = """
I have a Python Flask application in `app.py` with `requirements.txt`.
Please help me containerize it:
1. Create a `Dockerfile` that uses python:3.9-slim, installs dependencies, exposes port 5000, and runs the app.
2. Create a `docker-compose.yml` file to run the service, mapping port 5000:5000.
3. Add a `.dockerignore` file to exclude unnecessary files (like __pycache__, .git, venv).
"""

Execution Process

1. Planning

The Planner recognizes this as a DevOps task:

1. Analyze: Check requirements.txt to ensure dependencies are listed.
2. Dockerfile: Write the build instructions.
3. Docker Compose: Define the service orchestration.
4. Optimization: Create .dockerignore to keep the build context small.

2. Execution & Reflection

• Step 1 (Dockerfile): The Executor writes the Dockerfile.
  • Detail: It correctly sets WORKDIR /app, copies requirements.txt first (for layer caching), runs pip install, and then copies the rest of the code.
• Step 2 (Compose): It creates docker-compose.yml with version '3' syntax, defining the service web and port mapping 5000:5000.
• Step 3 (Ignore): It adds .dockerignore to exclude __pycache__ and .git.

The Result

Dockerfile:

FROM python:3.9-slim

WORKDIR /app

COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt

COPY . .

EXPOSE 5000

CMD ["python", "app.py"]

docker-compose.yml:

version: '3.8'
services:
  web:
    build: .
    ports:
      - "5000:5000"
    volumes:
      - .:/app

Key Takeaway

Zene isn't just for application code. It understands infrastructure configuration, best practices (like layer caching), and can set up your deployment pipeline in seconds.