mtanzi / reverse-proxy

Simple configuration-drive reverse proxy

Reverse Proxy

This is a simple example that shows how to build a configuration-driven reverse proxy in Go. This was written for educational purpose, by no mean is meant to be used in production ;)

configuration

The proxy by default uses the config.json file inside the main folder, you can define your own config file and pass the folder path using the --config_path path/to/config.json flag.

Here is the default config.json

{
  "ssl": true,
  "default_url": "localhost",
  "default_port": 1333,
  "rules": [
    {
      "matcher": "/auth",
      "downstream_port": 1331
    },
    {
      "matcher": "/api",
      "downstream_port": 1332
    }
  ]
}

Description

Field	Description
ssl	[bool] if true the proxy uses the HTTPS protocol and listen on port 443, otherwise it uses HTTP on port 8080
default_url	[string] default url for the downstream servers
default_port	[int64] default port for the downstream servers
roles	[[]object] Array of rules that describe the matcher and the downstream port and URL where forward the request to. matcher: [string] describes the URL path that, when matched, the proxy uses this rules downstream_port: [int64] Port of the downstream server downstream_url: [string] URL of the downstream server

Running

We can test the reverse-proxy using the default configuration file config.json.

In a terminal console we can start the reverse-proxy using the following command.

# Start the reverse Proxy with default config file
> go build && ./reverse-proxy
2020/01/01 19:32:41 Server listening on... https://localhost:443

# Start the reverse Proxy with specific config file
go build && ./reverse-proxy --config_path config.json
2020/01/01 19:32:41 Server listening on... https://localhost:443

In order to test our default configuration we need to start 3 different downstream servers, for each of them we should open a new terminal console and rung the following commands:

# On a new terminal: server 1
> go build && ./server -p 1331
Server listening on port 1331

# On a new terminal: server 2
> go build && ./server -p 1332
Server listening on port 1332

# On a new terminal: server 3
> go build && ./server -p 1333
Server listening on port 1333

Here is how it works.