NASH-F

NO-LIB (uses only syscalls), ASSEMBLY WRITTEN, SMALL (229 bytes), HTTP-ONLY (no TLS/SSL), FIXED (only send a static response) SERVER

This code is ABSOLUTELY NOT meant to be used for any purpose. It was written for fun after reading this question on Stackoverflow.

The final size of the ELF is 229 bytes.
Section headers are stripped, --omagic is used to make a single program header, no debug or symbol sections are created.
The source is assembled with nasm and linked with ld, you can look in the Makefile to see their command lines.
While ld already produce a small sized ELF, the final cut down is done by an ad-hoc (and very ugly and unsafe) C program that i called short.
The source is in short.c, it just removes the section headers and keep only the data up to the biggest offset covered by a program header (it assumes these come before the section headers).

At least 4 more bytes can be shaved off easily from the code at the cost of making it less configurable and using LFs in the HTTP response.
Surely the size can be further shrinked down by golfing the code (which I didn't really try hard to do), the current source is a good compromise between readability, configurability and size.
It will also correctly work, close the connection and avoid forking a new process since sending a very small, static HTTP response is way faster than spawning a new worker. All things the original code failed to do.

Configuration

The server will listen on 0.0.0.0:8800 (just like the original httpd example linked above). You can easily change that by editing the last line of the source. Particularly, you'll find a line MAKE_PORT 8800 that can be altered to change the port and a commented MAKE_INTERFACE 0, 0, 0, 0 line that can be used to pass the IPv4 of the interface to listen to (each octect separated by a comma).
The line is commented to exploit an ugly hack to save 4 bytes. Decommenting it will make the binary 4 bytes longer.

Build

Just run

make

It will build the httpd2 binary file (along with httpd2.o and short).

Docker image

I don't have docker to test the image or anything. I suppose you can create an image with:

tar c httpd2 | docker import - nashf

This should only include the httpd2 binary. NOTE httpd2 doesn't need any dependency library or any file, you don't need to use a base distribution image.

Further reduce the size

By setting:

html: db ""

you can reduce the size of the binary to 194 bytes. However, an empty response is not a valid HTTP response. Setting:

html: db "HTTP/1.0 204", 13, 10, 13, 10