PortChecker

PortChecker is an open-source utility that provides a simple API and web UI to test the availability of ports on a given hostname or IP address. It is designed to be lightweight with minimal dependencies and is supplied with production-ready Docker stacks and monitoring hooks.

Key Features

• HTTP API for checking port status on a provided hostname or IP, suitable for automation and integration
• Static web UI served behind Nginx for ad-hoc manual checks and quick diagnostics
• Production-ready Docker Compose stacks and development workflows for the frontend and backend
• Backend implemented in Python with a fast ASGI server setup (gunicorn + uvicorn workers) and a small dependency footprint
• Environment variables to control defaults and behavior (e.g., default host/port, ALLOW_PRIVATE to permit private IP checks)
• Prometheus /metrics endpoint for collecting API metrics and integrating with observability tooling

Use Cases

• Troubleshooting network connectivity and validating firewall rules for specific services and ports
• Integrating port checks into CI/CD pipelines or automation scripts via the REST API
• Monitoring endpoint accessibility and exporting API metrics to Prometheus for dashboards and alerts

Limitations and Considerations

• Intended for individual port availability checks rather than full port-scanning or discovery; not a replacement for comprehensive scanners
• Primary checks are TCP-based connect-style tests; UDP checks or protocol-level validation are not provided
• Default configuration disallows checks against private IP ranges unless explicitly enabled via configuration, which may limit internal network testing

PortChecker is a compact, purpose-built tool for quick port verification and lightweight monitoring. It suits developers and administrators who need an easy-to-deploy API and UI for validating network accessibility and integrating simple checks into observability or automation workflows.