# Nginx Unit — Dynamic Polyglot Application Server

> A lightweight application server by the Nginx team that runs Go, Python, Node.js, Java, Perl, PHP, Ruby, and WebAssembly apps behind a RESTful JSON API for zero-downtime configuration.

## Install

Save as a script file and run:

# Nginx Unit — Dynamic Polyglot Application Server

## Quick Use
```bash
# Install on Ubuntu/Debian
curl --output /usr/share/keyrings/nginx-keyring.gpg 
  https://unit.nginx.org/keys/nginx-keyring.gpg
apt install unit unit-python3.11 unit-php

# Start a Python app via the config API
curl -X PUT --data-binary @config.json 
  --unix-socket /var/run/control.unit.sock 
  http://localhost/config
```

## Introduction
Nginx Unit is an application server built by the Nginx core team that can run applications in multiple languages simultaneously. Configuration is managed through a RESTful JSON API, allowing you to add routes, change listeners, and deploy new app versions without restarts or dropped connections.

## What Nginx Unit Does
- Serves applications written in Python, PHP, Go, Node.js, Java, Ruby, Perl, and WebAssembly
- Provides a RESTful JSON API for runtime configuration without server restarts
- Routes requests by URI, host, method, headers, and other properties
- Handles TLS termination with automatic certificate management
- Serves static files alongside dynamic applications in a single server

## Architecture Overview
Unit uses a multi-process architecture with a controller process that owns the config API and router processes that handle incoming connections. Each application language runs in isolated worker processes managed by language-specific modules. Configuration changes are applied atomically: the controller validates the new config, forks new workers, drains old ones, and swaps routing tables with zero downtime.

## Self-Hosting & Configuration
- Install from the official repository for your OS or run the Docker image `docker run -d unit`
- Send JSON configuration to the control socket at `/var/run/control.unit.sock`
- Define listeners, routes, and applications in a single JSON document
- Update any subtree of the config with PUT, PATCH, or DELETE requests
- TLS certificates are uploaded as PEM bundles via the `/certificates` API endpoint

## Key Features
- Zero-downtime configuration: changes apply without connection drops
- Per-application process isolation with configurable worker counts
- Built-in request routing with pattern matching and header-based rules
- Static file serving with MIME type detection and directory listings
- Native WebAssembly support via the Wasm component model

## Comparison with Similar Tools
- **Nginx** — reverse proxy and static server; Unit adds native multi-language app serving with a config API
- **Apache** — venerable multi-module server; Unit offers simpler dynamic configuration and polyglot support
- **Gunicorn** — Python-only WSGI server; Unit handles multiple languages in one process tree
- **Caddy** — automatic HTTPS reverse proxy; Unit focuses on application serving rather than proxying

## FAQ
**Q: Can Unit replace Nginx as a reverse proxy?**
A: Unit can proxy and serve apps, but Nginx remains stronger for complex proxy scenarios like load balancing pools and caching. They are often used together.

**Q: How do I deploy a new app version without downtime?**
A: PUT the updated application config to the API. Unit spins up new workers, waits for in-flight requests to finish on old workers, then shuts them down.

**Q: Does Unit support HTTP/2?**
A: Yes. HTTP/2 is supported on TLS listeners. HTTP/3 (QUIC) support is in development.

**Q: What operating systems are supported?**
A: Unit runs on Linux, FreeBSD, and macOS. Official packages are available for major Linux distributions. Docker images are also provided.

## Sources
- https://github.com/nginx/unit
- https://unit.nginx.org/

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Source: https://tokrepo.com/en/workflows/asset-408c00ee
Author: Script Depot