Go HTTP Proxy Server

This is a simple HTTP proxy server written in Go. It reads backend configurations from a YAML file, performs health checks on the backends, and forwards incoming requests to healthy backends.

Features

• HTTP proxy (no HTTPS support)
• Configurable port, health check interval, and health check endpoint
• Regular health checks on backend servers
• Load balancing across healthy backends
• Fallback to other backends if one becomes unhealthy
• Optional bearer token authentication for backend requests
• Returns a 502 Bad Gateway error if all backends are down

Requirements

• Go 1.15 or higher
• gopkg.in/yaml.v2 package

Configuration

The proxy server is configured using a YAML file. By default, it looks for a file named backend.yml in the current directory. Here's an example configuration:

port: 8080
interval: 5
health: /health
bearer_token: your-token-here  # Optional: Add this if your backends require authentication
backends:
  - url: http://backend1.example.com
  - url: http://backend2.example.com
  - url: http://backend3.example.com

• port: The port on which the proxy server will listen (default: 80)
• interval: The interval in seconds between health checks (default: 3)
• health: The health check endpoint to use for all backends (default: /health)
• bearer_token: Optional authentication token for backend requests. When provided, it will be added as a bearer token in the Authorization header for all requests to backends (including health checks)
• backends: A list of backend servers to proxy requests to

Authentication

If your backend services require authentication, you can provide a bearer token in the configuration. When configured, the proxy will:

• Add the bearer token to all proxied requests to the backends
• Include the token in health check requests
• Use the format: Authorization: Bearer your-token-here

This is particularly useful when your backends are protected by authentication but you want to keep the proxy transparent to clients.

Building and Running

This project includes a Makefile to simplify building and running the server.

To build the server:

make build

To run the server:

make run

To clean up build artifacts:

make clean

To run tests:

make test

To install dependencies:

make deps

Running Manually

You can also run the server manually:

go run main.go --config backend.yml

Or, after building:

./proxy-server --config backend.yml

Docker

To build a Docker image:

make docker-build

To run the Docker container:

docker run -p 8080:8080 proxy-server:latest

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License.