underdog

HTTP/2 server-push for hapi

 

Lead Maintainer - Devin Ivy

Installation

``sh
npm install underdog
`

Usage

> See also the API Reference
>
> Underdog is intended for use with hapi v19+ and nodejs v12+ (see v4 for lower support).
>
> This module is currently under ad hoc maintenance, which means it relies fully on community support.

Underdog brings HTTP/2 server-push to hapi. The way it works is that you specify paths to resources that you'd like to push alongside a particular response. This is achieved with a call to the response toolkit decoration h.push(). Before hapi responds to the original request, those push-requests will be made internally and their results will be streamed to the client as push-responses. Even pushed resources can specify additional resources to push. You can't make this stuff up!

$3


`js
const Fs = require('fs');
const Http2 = require('http2');
const Hapi = require('@hapi/hapi');
const Underdog = require('underdog');

(async () => {

const listener = Http2.createSecureServer({
// See tests for a key/cert that you can use to try this out
key: Fs.readFileSync(${__dirname}/localhost.key),
cert: Fs.readFileSync(${__dirname}/localhost.cert)
});

const server = Hapi.server({
listener,
tls: true,
port: 3000
});

await server.register(Underdog);

server.route([
{
method: 'get',
path: '/',
handler: (request, h) => {

const response = h.response('');

h.push(response, 'push-me.js');

return response;
}
},
{
method: 'get',
path: '/push-me.js',
handler: (request) => {

return 'document.write(\'I was definitely pushed!\');';
},
// To demonstrate that it must have been pushed, not requested directly
config: { isInternal: true }
}
]);

await server.start();

console.log(Check-out ${server.info.uri} in your favorite HTTP/2-supporting client);
})();
`

$3


Underdog is compatible with nodejs's Http2Server and Http2SecureServer under the Compatibility API. Using any other HTTP server will simply disable server-push; h.push() will no-op and return { response, allowed: false } and h.pushAllowed() will return false.

Extras

- The HTTP/2 spec (here)
- For debugging HTTP/2 in Chrome, see chrome://net-internals/#http2`
- Nodejs's HTTP/2 docs (here)
- Shout-out to the original userland spdy and http2 modules.