Re: [9front] httpd minimal configuration

[sirjofri <sirjofri+ml-9front@sirjofri.de>]

21.06.2022 16:06:53 planless.user9 <planless.user9@proton.me>:
> There are no serious reasons for my preference and the rc-httpd 
> approach is also definitely an option for me. (Especially with your 
> instructions, which seem to be straightforward to realize.)
>
> I'm just trying to understand the system and that's why I read "Notes 
> on the Plan 9tm 3rd edition Kernel Source" and "The C Programming 
> Language". An implementation in C would therefore play into my hands a 
> bit (even more so, since I have almost no experience with scripts).

httpd is really a quite complex application, and if you want a pure C 
solution (without cgi) I suggest also looking into tcp80. There are a few 
sources for it, and I don't know if there is any canonical one.

Tcp80 is a simple binary you can copy to your service directory for the 
simplest setup. It uses /lib/namespace.httpd as the namespace file.

Since you are quite new to 9 I give you a few hints:

There is a program called aux/listen. This program listens to specific 
ports, starts associated processes and connects stdin/stdout with that 
process. Aux/listen is started by default on all cpu servers (see cpurc), 
and it listens to files in /rc/bin/service (or /cfg/$sysname/service if 
it exists).

To associate a port with a process you just have any kind of executable 
file in this directory called (protocol)(port), eg tcp443 would make 
aux/listen to port 443, and if someone calls, execute that exact file.

The program tcp80 can be placed in the service directory as is, or you 
build a wrapper rc script around it.

Most server processes like tcp80/httpd first set up their namespace 
according to the namespace.X file. Since web servers canonically are only 
interested in the /usr/web directory, the process binds this directory to 
/, which results in some nice sandboxing (eg it prevents %2f attacks).

Note that tcp80 only does GET and stuff like that, you can't POST with 
it. httpd can do a little more things, at least in its special handlers, 
like the wiki handler.

I hope this helps.

sirjofri