Switching upstream proxy without restarting server

[mhluska]

Is it possible to switch the upstream proxy host without restarting the server? I'm currently using the anonymizeProxy helper like so:

const proxyChain = require('proxy-chain');

const user = '...';
const pass = '...';
const vpnHost = process.argv[2];
const oldProxyUrl = `http://${user}:${pass}@${vpnHost}:80`;
const newProxyUrl = proxyChain.anonymizeProxy(oldProxyUrl);

function cleanup(url) {
  proxyChain.closeAnonymizedProxy(url);
}

newProxyUrl.then(url => {
  console.log(url);
  process.on('SIGINT',  () => cleanup(url));
  process.on('SIGTERM', () => cleanup(url));
});

But I have to restart the process to change the host. It would be nice if I could send a signal to the process and it would switch the upstream proxy without changing its own port.

I think one way to solve this might be to allow passing a desired port to anonymizeProxy.

---

Edit: I hacked around this by modifying PORT_SELECTION_CONFIG:

const proxyChainTools = require('proxy-chain/build/tools');
...
const vpnPort = process.argv[3];
...
// HACK: Force the proxy to choose a port by narrowing the min/max in config.
if (vpnPort) {
  proxyChainTools.PORT_SELECTION_CONFIG.FROM = parseInt(vpnPort, 10);
  proxyChainTools.PORT_SELECTION_CONFIG.TO = parseInt(vpnPort, 10);
}

Now I can quickly restart the node process to switch the host and keep the same port 🤷‍♂️

[jancurn]

Adding an optional port argument to anonymizeProxy() is a good idea. PR is welcome :)

[jirimoravcik]

Done in https://github.com/apify/proxy-chain/pull/214