80-docker-cicd

80 - CI/CD & Docker Architecture

What It Does

Demonstrates a production-ready containerized deployment workflow. Wraps a Python FastAPI application inside a multi-stage Docker image, orchestrates it with docker-compose.yml alongside a Redis cache, and includes a GitHub Actions CI/CD pipeline that automatically runs tests on every push before deployment.

Project Structure

80-docker-cicd/
  app/
    main.py           # FastAPI application
    config.py         # Environment-based configuration
    routes.py         # API route definitions
    tests/
      test_main.py    # Pytest unit tests
  Dockerfile          # Multi-stage production Docker image
  docker-compose.yml  # Multi-container orchestration (app + redis)
  .github/
    workflows/
      test.yml        # GitHub Actions CI pipeline
  requirements.txt    # Dependencies
  index.html          # Architecture diagram frontend
  README.md           # This file

Setup and Run

Option A: Run with Docker Compose

docker-compose up --build

Option B: Run Locally

pip install -r requirements.txt
uvicorn app.main:app --reload

Option C: Run Tests

pytest app/tests/ -v

Example Output

# docker-compose up --build
Building app...
Step 1/8 : FROM python:3.11-slim AS builder
Step 2/8 : WORKDIR /app
Step 3/8 : COPY requirements.txt .
Step 4/8 : RUN pip install --no-cache-dir -r requirements.txt
Step 5/8 : FROM python:3.11-slim
Step 6/8 : COPY --from=builder /usr/local/lib/python3.11 /usr/local/lib/python3.11
Step 7/8 : COPY app/ /app/
Step 8/8 : CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]
Successfully built abc123def456
Creating docker-cicd_redis_1 ... done
Creating docker-cicd_app_1   ... done
app_1    | INFO:     Uvicorn running on http://0.0.0.0:8000

# pytest output
app/tests/test_main.py::test_health_check PASSED
app/tests/test_main.py::test_get_items PASSED
app/tests/test_main.py::test_create_item PASSED
3 passed in 0.42s

Core Concepts

• Multi-Stage Build: Reduces final Docker image size by separating build and runtime stages.
• Docker Compose: Defines and runs multi-container applications with a single YAML file.
• GitHub Actions CI: Automatically runs pytest on every push/PR to catch regressions before merge.
• Environment Variables: config.py reads REDIS_URL from the environment, supporting both local and container modes.
• Health Checks: Docker and the API both expose health endpoints for monitoring.