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Comment by 082349872349872 | Hacker News Reader

If you wish, use the source. (Almost?) all early webservers were written in C.

Being largely unfamiliar with C, I would prefer conceptual resources over source code. The why is more important than the how. Hopefully that makes sense?

One of my favorite things to read is RFC 1945

Unfortunately, having done the same, there are a lot of lessons learned in existing source code that you won’t find elsewhere.

conceptually things are pretty limited - this is really simple if you are just playing around, and are just doing http 1

  o bind a socket
  o manage incoming connections
  o parse http headers
  o 'routing' - demultiplex handlers based on URL
  o encode response

unless its a little embedded thing one usually uses some kind of select/epoll machinery to multiplex the work on each channel. I guess thread-per-request is another model that works at moderate connection counts.

it helps to have some decent way of representing the header to send to the handler, C doesn't really have a great story here

I think the only funky thing is dealing with all the various body modes. so you will need to make some kind of protocol to deal with handlers and incremental updates if that's a thing for your use case.

I would just do the normal thing, read the rfc and spit out a couple hundred lines that talks to your browser...and then decide where if anywhere you need to go from there

A little context:

I'm specifically interested in compressing my analytics stack. I'm currently interacting with HTTP Messages at a higher level. The problem, as I see it, is the webserver is already doing this work but without useful output. I'd like to implement my analytics paradigm natively at the webserver level.

Parse server logs, if that helps.

I'm not sure I follow - you want a smart, small webserver that takes in a http request and updates an analytic store based on headers?

Sounds like something nginx might handle via lua scripting?

Otherwise, maybe you want: https://github.com/lammertb/libhttp

Or you might want to look at either of:

https://www.acme.com/software/thttpd/

https://github.com/openbsd/src/tree/master/usr.sbin/httpd

If you really want to build (another) web server in C.

Not entirely clear why want to use C for this, though?

for some applications it really might be easier to write a little thing than integrate into some giant framework. and I do think that building these things really helps one understand what's going on in all those layers

but I have to agree about C. unless the whole point is to ingrate with some existing codebase, there are several language choices which should turn this from a day or two of work to an hour or two - with a more robust outcome

I want to consume HTTP headers at the lowest possible level. The webserver would output a custom log file for direct consumption.

There are certainly off the shelf options, but I enjoy reinventing the wheel and dislike dependencies. I'd like to use C because I have interest in OS level webservers.

this is a 500 line server running in kernel mode on nanos

https://github.com/nanovms/nanos/blob/master/src/http/http.c

I would probably go for rust over c if the only reason for c is "os level". But either way, this is for requests from "real" http clients, eg: web browsers? Presumably you're already "trapped" at a pretty high level, like tls, http/2 etc?

Otoh, if low level is what you want, maybe look at:

https://2ton.com.au/rwasa/

and/or the library it is built on.

On the other hand, if you just want to log headers to a file, caddy can do that in a few lines:

https://caddyserver.com/docs/caddyfile/directives/log

AFAIK it can't log request bodies out of the box (like the content of a POST).

In that case you might be better off looking at writing a plugin for your existing webserver.

nginx, apache, etc, all allow writing modules that can be invoked at various parts of the HTTP-communication.

I don't technically run a webserver. I've built around Azure App Services which runs gunicorn behind the scenes.

Also, I rather own the majority of my stack even though its slower, harder, and more problematic.

C is the native language of Unix, so in a way it really is the language for formally discussing Unix concepts.

I'm surprised this isn't the popular opinion.

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