python-flask-probe

Minimal Python Flask application used for deployment validation across any environment (local, Docker, Kubernetes, ECS, etc.).

This is the Python counterpart to the node-express-probe and validates deployment across different stacks.

Use Cases

• Validate Docker builds and images
• Test Kubernetes / ECS deployments
• Verify CI/CD smoke tests
• Experiment with runtime behavior across different platforms
• Backstage integration testing

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Endpoints

Endpoint	Method	Purpose
/	GET	Root - basic service info
/health	GET	Health check (returns JSON)
/healthz	GET	Kubernetes-style health check
/ready	GET	Readiness probe
/live	GET	Liveness probe
/api/v1/info	GET	Detailed app info (time, hostname, version)
/api/v1/version	GET	Version and commit info

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Local Development

Quick Start

# Install dependencies
pip install -r requirements.txt

# Run the app
python src/app.py

The app will start on http://localhost:8080

With Environment Variables

# Set custom version and commit
APP_VERSION=2.0.0 APP_COMMIT_SHA=abc123 python src/app.py

Docker Local

# Build image
docker build -t python-probe:latest .

# Run container
docker run -p 8080:8080 python-probe:latest

# With environment variables
docker run -p 8080:8080 \
  -e APP_VERSION=2.0.0 \
  -e APP_COMMIT_SHA=abc123 \
  python-probe:latest

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Kubernetes Deployment

The app includes proper probe endpoints for Kubernetes:

livenessProbe:
  httpGet:
    path: /live
    port: 8080
  initialDelaySeconds: 5
  periodSeconds: 10

readinessProbe:
  httpGet:
    path: /ready
    port: 8080
  initialDelaySeconds: 5
  periodSeconds: 5

See k8s/deploy.yaml for full deployment example.

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ECS / EC2 Deployment

The app works on any environment. Set environment variables via:

• EC2: User data script or SSM Parameter Store
• ECS: Task definition environment variables
• Docker: -e flag or .env file

# Example EC2 user data
#!/bin/bash
export APP_VERSION=1.0.0
export APP_COMMIT_SHA=${GIT_COMMIT}
python /app/src/app.py

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Configuration

Variable	Default	Purpose
PORT	8080	Port to listen on
APP_VERSION	1.0.0	Application version
APP_COMMIT_SHA	unknown	Git commit SHA (for tracking)

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Production

For production, the Docker image uses Gunicorn (4 workers) instead of Flask's development server:

# Manual production run
gunicorn --bind 0.0.0.0:8080 --workers 4 --access-logfile - app:app

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Development

Project Structure

src/
  app.py          # Flask application
requirements.txt  # Python dependencies
Dockerfile        # Docker image definition
k8s/              # Kubernetes manifests
chart/            # Helm chart (optional)

Testing Endpoints

# Health checks
curl http://localhost:8080/health
curl http://localhost:8080/live
curl http://localhost:8080/ready

# App info
curl http://localhost:8080/api/v1/info
curl http://localhost:8080/api/v1/version

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License

MIT