fetch vs http difference

[shanmugharajk]

If I use the fetch with proxy setup it works fine. In the same machine if I use http it throws with ECONNRESET error. I don't know what's the difference between these two core implementations..

I got into this issue originally by using the splunk-logging library which internally using needle which uses the native http modules. The I tired with the http module separately and got this ECONNRESET.

Could someone help me understand how it can happen like this between fetch vs http?

fetch example which works

import proxy from "undici";

const proxyUrl = new URL("proxy url");

const agent = new proxy.ProxyAgent({
  uri: proxyUrl.protocol + proxyUrl.host,
});

fetch(
  "https://domain:443/services/collector/event/1.0",
  {
    dispatcher: agent,
    method: "POST",
    body: '{}',
    headers: {
      "Content-type": "application/json; charset=UTF-8",
      authorization: "Splunk token",
    },
  }
)
  .then((res) => {
    console.log("== res", res.statusText);
  })
  .catch((e) => {
    console.log("== err", e);
  });

https request code

import http from "node:https";
import { ProxyAgent } from "proxy-agent";

const agent = new ProxyAgent();

const postData = JSON.stringify({});

const options = {
  hostname: "",
  agent,
  protocol: "https:",
  port: 443,
  path: "/",
  method: "POST",
};

const req = http.request(options, (res) => {
  console.log(`STATUS: ${res.statusCode}`);
  console.log(`HEADERS: ${JSON.stringify(res.headers)}`);
  res.setEncoding("utf8");
  res.on("data", (chunk) => {
    console.log(`BODY: ${chunk}`);
  });
  res.on("end", () => {
    console.log("No more data in response.");
  });
});

[liudonghua123]

I read the doc about proxy-agents(code), did you configured http_proxy / https_proxy / no_proxy / etc. env vars, you can configure them explicitly.

You could also try to use the built-in https.Agent. See the example code from NodeJS: how to route HTTPS requests through an HTTP proxy without any external dependencies (optimized version).

The main code is the followings.

    // Async private method, used only internally by HttpsWithProxyClient
    // Handle the connection with the HTTP proxy
    // In case the connection is successful, it returns a new http.Agent with keepAlive activated
    async _connectToProxy(url) {
        return new Promise((resolve, reject) => {
            const headers = {
                'Proxy-Authorization': 'Basic ' + Buffer.from(this.proxyConf.proxy_username + ':' + this.proxyConf.proxy_password).toString('base64')
            }

            const urlParsed = new URL(url);
            http.request({ // establishing a tunnel
                host: this.proxyConf.proxy_host,
                port: this.proxyConf.proxy_port,
                method: 'CONNECT',
                path: `${urlParsed.hostname}:443`,
                headers
            }).on('connect', (res, socket) => {
                if (res.statusCode === 200) {
                    resolve(new https.Agent({ socket: socket, keepAlive: true }));
                } else {
                    reject('Could not connect to proxy!')
                }

            }).on('error', (err) => {
                reject(err.message);
            }).on('timeout', (err) => {
                reject(err.message);
            }).end();
        });
    }