HTTP webserver

Single-threaded IO multiplexing HTTP web server written in C++.

Features

• GET, HEAD, POST, PUT, DELETE HTTP methods.
• static HTML files and CGI.
• Configuration rules similar to nginx. It includes alias, auto_index, cgi_pass, error_page, limit_except, location, return along with essentials such as index, listen, root, server_name.
• Virtual server that allows exposing multiple servers on same IP:PORT pair. Uses HTTP host name field to find servers.
• Multi-platform(Linux, macOS). It have been written mostly using UNIX system calls and C++ standard library.

Debug

• ERROR, WARNING, INFO, DEBUG logging levels.
• Debug build(make debug) that enables DEBUG logging and compiler sanitizer.

Build

C++ compiler and GNU Make are needed for build.

Command

There are make release and make debug. Use make debug to enable debug features.

make command follows previous one. Using make after make debug will start debug build. Use make release or make fclean to reset the build mode to release.

Config

Servers are defined at the configuration file. config directory contains examples. See nginx documentation to learn detail.

Overview

server {
	server_name mydomain.com;

	root	html;

	index	index.php;

	listen	8080;

	cgi_pass .php cgi-bin/php-cgi;

	location /resource/ {

		limit_except GET;

		client_max_body_size 100;

		alias tester_dir/YoupiBanane/;
	}
}

• server { server_definition }

A server block will initialize a virtual server according to the server definition.

• server_name name

Set the name of a virtual server. If multiple servers share same IP or port, they are identified by examining the server name.

• root path

Set the root path for URL-to-path mapping.

Given a URL http://mydomain.com/hello/world, the domain part of the URL(mydomain.com) will be translated to IP:PORT for IPC. File path is root path appended by the path part(/hello/world). If WEBSERV_ROOT is /home/harim/webserver and root path is html, The file path is /home/harim/webserver/html/hello/world.

If path starts with /, WEBSERV_ROOT is not used(i.e. path is used as absolute path). WEBSERV_ROOT is set when build is done.

• index file

Without index file, http://mydomain.com/ cannot be mapped to a file because path part is / and it will map to root path. Index file is index.html by default.

• listen (port|addr|addr:port)

Address passed to listening socket of the server.

• cgi_pass postfix executable_path

If the path part ends with postfix(e.g. mydomain.com/index.php), server will spawn CGI by executing $WEBSERV_ROOT/executable_path and communicate with it to acquire the body of HTTP response.

• autoindex

If the path part is not a file and there's no index file, respond with autoindex which is a generated HTML file for path traversal.

• return address

Respond with 301 redirect.

• error_page status_code file

Respond with status_code and content of file as body.

• client_max_body_size integer

Limit the size of the body of HTTP request. INT32_MAX by default.

Location

location path { location_definition }

Maps a specific path to location which can have its own index, root, autoindex, return. It will inherit other options from the server.

• alias

Instead of using root of server, assign a independent path. Starting / matters like root.

• limit_except method( method)*

Limit the HTTP method(s) that location can receive.

Execute

It requires a configuration file to execute.

Option

Use --log=[level] command line argument to adjust logging level. Default is INFO. ERROR, WARNING, INFO, DEBUG are available(case sensitive).

HTTP

we have implemented subset of server-side HTTP/1.1, priotizing MUST and SHALL requirements such as HTTP message structure, Content-Length, status code and etc.