kor-proxy

promise proxy middleware for koa, support Load-Balance

Install

npm install kor-proxy

Aim

This middleware is supported do two things:

1. Set Proxy Server Four options: (host [, protocol] [, auth] [, port])
2. Rewrite the proxy request Header Match request will respond automatical internally use Stream.pipe.

Hello Kor-proxy

const Koa = require('neat-kor'); // router wrap for Koa
const proxy = require('kor-proxy');
const app = new Koa();

const ext = {
  timeout: 1000,
  headerRewrite() {
    // selected, deal req.headers before proxy;
  },
  dealTimeout() {
    // if none, will throw ('proxy-timeout');
  },
  rr: [options1, options2, ...] // every time merge one element to options
}

app.get('/proxy1', proxy('https://auth:pwd@test.url.com:8080', ext));

// the same as http(s).request 's options parameter
const options = {
  protocol: 'https', // defalut is http:
  auth: 'auth:pwd', // default is null
  host: 'test.url.com', // must pass!
  port: 8088, // defalut is 80(443)
};
app.get('/proxy2', proxy(options, ext));

Load-Balance

const Koa = require('neat-kor'); // router wrap for Koa
const proxy = require('kor-proxy');
const app = new Koa();

const rr = [{
    host: 'target.url.com1',
    port: 8000
  },
  {
    host: 'target.url.com2',
    port: 9000
  },
];

const ext = {
  timeout: 1000,
  headerRewrite() {
    // selected, deal req.headers before proxy;
  },
  dealTimeout() {
    // if none, will throw ('proxy-timeout');
  },
  rr// every time merge one element to options, except the same key.
}


// the same as http(s).request 's options parameter
const options = {
  port: 8088, // defalut is 80(443)
};
// Important: In this example, proxy server port will always be 8088, because options is prefer than rr's element.
app.get('/proxy2', proxy(options, ext));

API

proxy(options [, ext])

• options(str | obj) - Default is {}.The absolute url path for proxy target, Eg: http(s)://auth:pwd@www.proxy.com:8080.It's used for getting protocol, auth, host, port properties, can also be defined explicitly in options.(Prefer than ext.rr's element.)Which will pass to http(s).request's options parameters. Eg: agent, headers..
• ext (obj) - Default is {}.extension object.
• ext.rr (Array) - : Default is undefined.Every element of arr will merge into options, in a round-robin manner. especially when need Load-Balance. (If rr's element have same key with options, it will not merge into, please put common key in options, dynamic for Load-Banlance put in rr )
• ext.timeout (num) - Defalut is 15s, timeout(ms) between proxy request send and recieve response.
• ext.headerRewrite (fn) - : Default is undefined, deal headers before proxy, recieve one param, the raw message.headers.
• ext.dealTimeout (fn) - : Default is undefined, deal timeout error when proxy, if none will ctx.throw('proxy-timeout').
• ext.client (fn) - : Default is undefined, Custom client, can created by neat-http, which kor-proxy is based.This method is set, ext.rr will be ignore(Because the client may be have rr configuration).

Error Handle

• When catch Errors, will throw through ctx.throw(error.message), should deal in your koa app.