Proxy Go

A lightweight, configurable reverse proxy server written in Go that routes HTTP requests to multiple backend services based on endpoint paths.

Features

• 🚀 Simple reverse proxy implementation using Go's httputil.ReverseProxy
• ⚙️ YAML-based configuration for easy management
• 🔀 Route requests to multiple backend services based on path
• 💚 Built-in health check endpoint
• 📝 Request logging with timestamps
• 🐳 Docker-ready setup for testing with multiple backend services

Prerequisites

• Go 1.25.4 or higher
• Docker (optional, for running demo services)

Project Structure

proxy_go/
├── cmd/
│   └── main.go              # Application entry point
├── internal/
│   ├── configs/
│   │   └── config.go        # Configuration loader using Viper
│   └── server/
│       ├── server.go        # HTTP server setup
│       ├── proxy_handler.go # Reverse proxy handler logic
│       └── healthcheck.go   # Health check endpoint
├── settings/
│   └── config.yaml          # Server and routing configuration
├── go.mod                   # Go module dependencies
├── Makefile                 # Build and run commands
└── README.md

Installation

1. Clone the repository:

git clone <repository-url>
cd proxy_go

2. Install dependencies:

go mod download

Configuration

Edit the settings/config.yaml file to configure your proxy server:

server:
  host: "localhost"
  listen_port: "8080"

resources:
  - name: Server1
    endpoint: /server1
    destination_url: "http://localhost:8081"
  - name: Server2
    endpoint: /server2
    destination_url: "http://localhost:8082"
  - name: Server3
    endpoint: /server3
    destination_url: "http://localhost:8083"

Configuration Options

• server.host: The host address to bind the proxy server to
• server.listen_port: The port on which the proxy server listens
• resources: Array of routing rules
  • name: Descriptive name for the resource
  • endpoint: URL path prefix to match
  • destination_url: Target backend service URL

Usage

Running the Proxy Server

Using Make:

make run-proxy-server

Or directly with Go:

go run cmd/main.go

The server will start on http://localhost:8080 (or as configured).

Running Demo Backend Services (Optional)

To test the proxy with Docker containers:

make run-containers

This will start three demo services on ports 8081, 8082, and 8083.

To stop the demo services:

make stop

Health Check

Check if the proxy server is running:

curl http://localhost:8080/ping

Expected response: pong

Making Requests Through the Proxy

Once configured, requests to the proxy endpoints will be forwarded to the respective backend services:

# Request to /server1 will be proxied to http://localhost:8081
curl http://localhost:8080/server1

# Request to /server2 will be proxied to http://localhost:8082
curl http://localhost:8080/server2

# Request to /server3 will be proxied to http://localhost:8083
curl http://localhost:8080/server3

How It Works

1. The proxy server reads configuration from settings/config.yaml
2. For each resource, it creates a reverse proxy pointing to the destination URL
3. When a request matches an endpoint, the proxy:
   • Logs the incoming request
   • Updates request headers (X-Forwarded-Host, Host)
   • Modifies the URL scheme and host
   • Strips the endpoint prefix from the path
   • Forwards the request to the backend service
   • Returns the backend response to the client

Dependencies

• Viper - Configuration management

Development

Available Make Commands

• make run-proxy-server - Start the proxy server
• make run-containers - Start demo Docker containers
• make stop - Stop all demo containers

Or run your app server for test