koa-http-proxy-middleware-fix
v0.0.3
Published
koa-http-proxy-middleware-fix
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Maintainers
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koa-http-proxy-middleware
[email protected]/next middlware for http proxy
Powered by http-proxy
.
Installation
$ npm install koa-http-proxy-middleware --save
Options
http-proxy events
options.events = {
error (err, req, res) { },
proxyReq (proxyReq, req, res) { },
proxyRes (proxyRes, req, res) { }
}
Usage
// dependencies
const Koa = require('koa')
const {httpProxy} = require('koa-http-proxy-middleware')
const httpsProxyAgent = require('https-proxy-agent')
const app = new Koa()
// middleware
app.use(httpProxy('/octocat', {
target: 'https://api.github.com/users',
changeOrigin: true,
agent: new httpsProxyAgent('http://1.2.3.4:88'),
rewrite: path => path.replace(/^\/octocat(\/|\/\w+)?$/, '/vagusx'),
logs: true
}))
Source Code
/**
* Dependencies
*/
const url = require('url')
const HttpProxy = require('http-proxy')
const { mathPath } = require('match-path-plus')
/**
* Constants
*/
const proxy = HttpProxy.createProxyServer()
let eventRegistered = false
/**
* Koa Http Proxy Middleware
*/
export const httpProxy = (urlPattern, options?) => (ctx, next) => {
if (!mathPath(urlPattern, ctx.req.url)) return next()
let opts = Object.assign({}, options)
if (typeof options === 'function') {
const { params, path } = mathPath(urlPattern, ctx.req.url)
opts = options.call(options, params)
}
// object-rest-spread is still in stage-3
// https://github.com/tc39/proposal-object-rest-spread
const { logs, rewrite, events } = opts
const httpProxyOpts = Object.keys(opts)
.filter(n => ['logs', 'rewrite', 'events'].indexOf(n) < 0)
.reduce((prev, cur) => {
prev[cur] = opts[cur]
return prev
}, {})
return new Promise((resolve, reject) => {
ctx.req.oldPath = ctx.req.url
if (typeof rewrite === 'function') {
ctx.req.url = rewrite(ctx.req.url)
}
if (logs) logger(ctx, opts.target)
if (events && typeof events === 'object' && !eventRegistered) {
Object.entries(events).forEach(([event, handler]) => {
proxy.on(event, handler)
})
eventRegistered = true
}
proxy.web(ctx.req, ctx.res, httpProxyOpts, e => {
const status = {
ECONNREFUSED: 503,
ETIMEOUT: 504
}[e.code]
if (status) ctx.status = status
resolve()
})
})
}
function logger(ctx, target) {
console.log('%s - %s %s proxy to -> %s', new Date().toISOString(), ctx.req.method, ctx.req.oldPath, url.resolve(target, ctx.req.url))
}