Use proxy response cookie for further proxy request

Expected behavior

Not able to save cookies from proxy response to the session.

Actual behavior

Setup

• http-proxy-middleware: 0.15.0
• server: express + 4.13.3

proxy middleware configuration

const proxyOptions = {
  target: targetUrl,                // target host
  pathRewrite: function (path) {
    return path.replace('/api', '')
  },
  logLevel: 'debug',
  onProxyReq: function (proxyReq, req, rsp) {
    proxyReq.path = req.path + '?ticket=' + req.session.pt[targetUrl]
    if(req.session.cookie.pt_session_id && req.session.cookie.pt_session_id[targetUrl]) {
      proxyReq.writeHead(req.session.cookie.pt_session_id[targetUrl])
    }
  },
  onProxyRes: function onProxyRes(proxyRes, req, res) {
    console.log('RAW Response from the target', JSON.stringify(proxyRes.headers, true, 2))
    req.session.cookie.pt_session_id = req.session.cookie.pt_session_id || {}
    req.session.cookie.pt_session_id[targetUrl] = proxyRes.headers['set-cookie']
  }
}
var apiProxy = proxy('/api', proxyOptions);

server mounting

var app = express();

app.use(apiProxy);
app.listen(3000);

Hi,

Thanks guys for the awesome middleware which made my life very easy. We need minor information regarding my usecase. We are implementing CAS proxy using then middleware. Our cas server behaviour is it, first time it accept the proxy ticket and provides the _session_id, it expects that _session_id in further request. I am not able to save it to session and use it. Have I missed something. ?

proxy response looks like below:

RAW Response from the target {
   "server": "nginx/1.6.2",
   "date": "Fri, 13 May 2016 06:38:26 GMT",
   "content-type": "application/json;charset=utf-8",
   "content-length": "2071",
   "connection": "close",
   "status": "200 OK",
   "set-cookie": [
     "_session_id=randombignumber; path=/; HttpOnly"
   ]
}

[olalonde]

I had a similar problem with front end rewriting /api path to /. e.g. http://www.website.com/api/whoami would be forwarded to http://api.website.com/whoami, but api.website.com would set cookies with the path param not prefixed with /api.

Solved with the following code (reads set-cookie from incoming target response and prefixes cookie path params with /api:

import cookiejar from 'cookiejar'

app.use('/api', proxy({
  target: 'http://api.domain.com',
  pathRewrite: { '^/api': '' },
  onProxyRes: (proxyRes) => {
    // prepend /api to cookie paths
    const setCookieHeaders = proxyRes.headers['set-cookie'] || []
    const modifiedSetCookieHeaders = setCookieHeaders
      .map(str => new cookiejar.Cookie(str))
      .map(cookie => {
        if (cookie.path && cookie.path[0] === '/') {
          cookie.path = `/api${cookie.path}`
        }
        return cookie
      })
      .map(cookie => cookie.toString())
    proxyRes.headers['set-cookie'] = modifiedSetCookieHeaders
  },
  changeOrigin: true,
}))

Would be nice if this was a configurable option for http-proxy-middleware since it is probably a fairly common scenario.

[chimurai]

You can try to relay all headers back and forth. Hopefully this will take care of you cookie issue.

const proxyOptions = {
  onProxyReq: relayRequestHeaders,
  onProxyRes: relayResponseHeaders
}

function relayRequestHeaders(proxyReq, req) {
  Object.keys(req.headers).forEach(function (key) {
    proxyReq.setHeader(key, req.headers[key]);
  });
}

function relayResponseHeaders(proxyRes, req, res) {
  Object.keys(proxyRes.headers).forEach(function (key) {
    res.append(key, proxyRes.headers[key]);
  });
}

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Please use StackOverflow to troubleshoot your setup if you need further assistance.

Thanks.