[HPM] Error occurred while trying to proxy request

[djleonskennedy]

Expected behavior

make proxy request

Actual behavior

make proxy request unstable

Setup

• http-proxy-middleware: 0.17.1
• server: webpack -dev-server: 2.3.0

proxy middleware configuration

https://gist.github.com/djleonskennedy/e0521313bc6229d32b006e6d236c4ea3

server mounting

https://webpack.github.io/docs/webpack-dev-server.html#proxy

Hello this issue more about clarification, i have regular proxy to redirect requests to avoid CORS
however also we need to be connected to customer VPN, and sometimes we have proxy worked and sometimes we have next

[HPM] Error occurred while trying to proxy request /login from localhost:4200 to <TARGET> (ETIMEDOUT) (https://nodejs.org/api/errors.html#errors_common_system_errors)

but without proxy TARGET endpoint works well always so we've decided that it can be problem with proxying some, could you please clarify about it?

Might i need to add some configuration?

Thank you

[chimurai]

Don't see anything unusual in your configuration.
Understand your <TARGET> is masked in the example. Can you provide an anonymized <TARGET> example? Since you can have many variations for target.

Wondering if webpack-dev-server might cause the issue...

Can you try out a simplified setup with just express + http-proxy-middleware and see if the issue persists?

https://github.com/chimurai/http-proxy-middleware/blob/master/recipes/servers.md#express

var express = require('express');
var proxy = require('http-proxy-middleware');

var app = express();

app.use(proxy("/api/auth/login", {
  "target": "<TARGET>",
  "secure": false,
  "logLevel": "debug",
  "pathRewrite": {
    "^/api/auth": ""
  },
  "changeOrigin": true
}))

app.use(proxy("/api/auth/token/refresh", {
  "target": "<TARGET>",
  "secure": false,
  "logLevel": "debug",
  "pathRewrite": {
    "^/api/auth": ""
  },
  "changeOrigin": true
}))

app.use(proxy("/api/loans", {
  "target": "<TARGET>",
  "secure": false,
  "logLevel": "debug",
  "changeOrigin": true
}))

app.use(proxy("/api/am", {
  "target": "<TARGET>",
  "secure": false,
  "logLevel": "debug",
  "changeOrigin": true
}))

app.use(proxy("/api/products", {
  "target": "<TARGET>",
  "secure": false,
  "logLevel": "debug",
  "changeOrigin": true
}))

app.listen(3000);

[djleonskennedy]

@chimurai Thank you for answer, TARGET is internal customer url that works if access to it directly (without proxy)

I'll try express + http-proxy-middleware, and let you know as fast as i'll try

Thank you

[djleonskennedy]

@chimurai problem with local environment

[chimurai]

Glad you've found an answer.
Care to share the cause and solution?

[djleonskennedy]

@chimurai We've solved with using nginx

localhost:4200 (angular CLI) -> http-proxy-middleware -> ngnix -> (vpn)

[AndriiDidkivsky]

Yeah, we've not configured our application just with http-proxy-middleware
So it's perhaps your issue.

It would be great to solve that problem just with one proxy :)

[chimurai]

Using multiple proxies is indeed not ideal.

Can you provide an isolated example in which this issue is reproducible?

I'll be happy to dive into it and see if it is an issue with HPM.

[AndriiDidkivsky]

You can go to our office and we'll show you. :)
There is only one case to reproduce. VPN connection to environment and proxy server to some API.

Can you provide an isolated example in which this issue is reproducible?

Do you know any services where we can use vpn + proxy to provide an isolated example ?
I might try to create an small example for you in this case.

[chimurai]

Do you know any services where we can use vpn + proxy to provide an isolated example ?

Not aware of any currently.

Would be nice if you could spend some small effort to debug the issue.

[djleonskennedy]

@chimurai According to my little investigation this is scenario with response delay from vpn connection.

When i do request it goes throw proxy to nginx (in our current solution), if i'm not wrong HPM receives success response from nginx so HPM doesn't fails.

nging waits for response from server (which is under vpn).
It can be long response, even for 2 minutes

before using nginx

I've tried option.proxyTimeout however it didn't help, migth i've made something whrong, but you can try to reproduce it with vpn and long responce emulation.

Regards

[wmzy]

I get the error ([HPM] Error occurred while trying to proxy request /api/v1/xxx from localhost:3000 to http://xxx.com (ECONNRESET) (https://nodejs.org/api/errors.html#errors_common_system_errors)) when I post a body.
Solved it by remove the express body-parser middleware before HPM.
Mybe help for someone.

[yuankui]

In my case I add a header in the client(proxy), then solves it

may this will help you

module.exports = function(app) {
    app.use(proxy('/api', {
        target: 'http://127.0.0.1:8080/',
        headers: {
            "Connection": "keep-alive"
        },
    }));
};

[lkaratun]

@wmzy I tried your solution (removed body-parser from the express app) and it worked, but I don't understand how the app is still working without body-parser. Isn't it required with express v.4+?(I was testing with express version 4.12.2)