Example code for different ways to utilize HTTP streams in JavaScript.
There's a simple process in 1-logger.js that simply appends a JSON string to a file logfile.log every second.
We'll use this as our imaginary service that pipes out data.
Run it:
node 1-logger.jsThe backend server that "calls the service" is a Node.js http server in 2-upstream-server.js that's simply using node:child_process.spawn to run tail -f logfile.log and piping that out on the response.
In a real server maybe the request would execute a shell command to an LLM, and you'd pipe back the output, not waiting until it finishes.
Run it:
node 2-upstream-server.jsTODO: using Cloudflare as a middleman / proxy to prevent exposing your upstream.
There's a stub code in 3-cloudflare-tunnel.js that's untested but should basically be correct.
Note
To run this locally, I'm using http-server with a special pass-through command which is currently pointed at the upstream.
Inside the index.html the request is a stream, which simply prepends them to the <body> as the chunks come in.
(Each chunk is one or more JSON lines, because in the request setup it may end up being several chunks stacked in one http frame. For a setup like this, once the http connection etc is established, it will typically settle to one line per chunk.)
Run it:
npm start