The CONNECT method is used to allow an HTTP/2 server to be used as a proxy for TCP/IP connections.

    A simple TCP Server:

    1. const net = require('net');
    3. const server = net.createServer((socket) => {
    4.   let name = '';
    5.   socket.setEncoding('utf8');
    6.   socket.on('data', (chunk) => name += chunk);
    7.   socket.on('end', () => socket.end(`hello ${name}`));
    8. });
    10. server.listen(8000);

    An HTTP/2 CONNECT proxy:

    1. const http2 = require('http2');
    2. const { NGHTTP2_REFUSED_STREAM } = http2.constants;
    3. const net = require('net');
    5. const proxy = http2.createServer();
    6. proxy.on('stream', (stream, headers) => {
    7.   if (headers[':method'] !== 'CONNECT') {
    8.     // Only accept CONNECT requests
    9.     stream.close(NGHTTP2_REFUSED_STREAM);
    10.     return;
    11.   }
    12.   const auth = new URL(`tcp://${headers[':authority']}`);
    13.   // It's a very good idea to verify that hostname and port are
    14.   // things this proxy should be connecting to.
    15.   const socket = net.connect(auth.port, auth.hostname, () => {
    16.     stream.respond();
    17.     socket.pipe(stream);
    18.     stream.pipe(socket);
    19.   });
    20.   socket.on('error', (error) => {
    21.     stream.close(http2.constants.NGHTTP2_CONNECT_ERROR);
    22.   });
    23. });
    25. proxy.listen(8001);

    An HTTP/2 CONNECT client:

    1. const http2 = require('http2');
    3. const client = http2.connect('http://localhost:8001');
    5. // Must not specify the ':path' and ':scheme' headers
    6. // for CONNECT requests or an error will be thrown.
    7. const req = client.request({
    8.   ':method': 'CONNECT',
    9.   ':authority': `localhost:${port}`
    10. });
    12. req.on('response', (headers) => {
    13.   console.log(headers[http2.constants.HTTP2_HEADER_STATUS]);
    14. });
    15. let data = '';
    16. req.setEncoding('utf8');
    17. req.on('data', (chunk) => data += chunk);
    18. req.on('end', () => {
    19.   console.log(`The server says: ${data}`);
    20.   client.close();
    21. });
    22. req.end('Jane');