mediasoup v3: get bindable private IP

mediasoup-get-bindable-ip.ts

import * as os from 'os';
import * as dgram from 'dgram';

async function detectBindableIp(family: 'IPv4' | 'IPv6'): Promise<string> {
  const ifaces = os.networkInterfaces();

  // Iterate all network interfaces.
  for (const iface of Object.keys(ifaces)) {
    // Iterate all network addresses in each network interface.
    for (const address of ifaces[iface]) {
      // Ignore if family doesn't match.
      if (address.family !== family) {
        continue;
      }

      // Ignore if internal.
      if (address.internal) {
        continue;
      }

      const ip = address.address;

      console.log(`detectBindableIp() | testing iface:${iface}, ip:${ip}`);

      try {
        await new Promise((resolve, reject) => {
          // Verify we can bind into it.
          const socketType = family === 'IPv4' ? 'udp4' : 'udp6';
          const socket = dgram.createSocket({ type: socketType });

          socket.on('error', error => {
            socket.close();
            reject(error);
          });

          try {
            socket.bind({ port: 0, address: ip }, () => {
              socket.close();
              resolve();
            });
          } catch (error) {
            socket.close();
            reject(error);
          }
        });

        // Resolve with this IP.
        console.log(`detectBindableIp() | got bindable ${family}: ${ip}`);

        return ip;
      } catch (error) {
        console.warn(
          `detectBindableIp() | bind test failed for ${ip}: ${error}`,
        );
      }
    }
  }

  // If we are here if means that we got no bindable IP for the requested
  // family, so throw.
  console.error(`detectBindableIp() | no bindable ${family} found`);

  throw new Error(`no bindable ${family} found`);
}