Webserv Project

Overview

Webserv is a lightweight HTTP/1.1 server built entirely in C++. It serves static assets, executes CGI scripts, and exposes a configurable routing layer inspired by NGINX. The codebase implements its own epoll-based event loop, request parser, response builder, and logging utility.

Features

• Non-blocking IO backed by an epoll manager with custom callback dispatch.
• Static file serving with MIME type detection and graceful error pages.
• CGI execution with environment preparation and body streaming.
• Upload handling and configurable locations via webserv.conf or YAML.
• Colored runtime logging with adjustable verbosity.

Architecture At A Glance

• Request lifecycle: The Server accepts connections, Client buffers track per-socket state, HTTPParser incrementally fills an HTTPRequest, and FileServer/CGIHandler produce an HTTPResponse that is streamed back through the same client.
• Event loop: EpollManager (src/core/Epoll.*) maps file-descriptor events to function pointers so the server can react to readable, writable, and error states without blocking.
• Configuration: Config and ServerConfig (src/config/) parse NGINX-style and YAML files, building location rules, upload limits, and CGI directives that the runtime references on every request.
• Utilities: Logger (src/utils/Logger.*) formats colored log lines with timestamps and optional file-descriptor context; Utils and String provide path, time, and string helpers shared across the modules.

Example: Bootstrapping the server

// src/main.cpp
Config config;
if (!config.parseNginx("webserv.conf")) return 1;

Server server;
Server::setSignalInstance(&server);
if (!server.init(&config) || !server.start()) return 1;

Logger::setLevel(INFO);
server.run();
server.stop();

The main routine validates the configuration, registers signal handlers, and then hands control to Server::run(), which blocks inside the epoll loop until shutdown.

Example: Routing and response generation

// src/core/Server.cpp (excerpt)
void Server::generateHttpResponse(Client& client, const HTTPRequest& request) {
    ServerConfig* serverConfig = _config->getServerByPort(request.getPort());
    const LocationConfig* location = serverConfig->findLocation(request.getURI());

    if (location && location->cgi_enabled &&
        Utils::endsWith(request.getURI(), location->cgi_extension)) {
        std::string uri = request.getURI();
        std::string scriptPath = location->root + uri.substr(location->path.length());
        CGIHandler handler(request, *location, scriptPath);
        HTTPResponse response;
        if (handler.execute(response)) {
            client.setWriteBuffer(response.toString());
            return;
        }
    }

    HTTPResponse response = FileServer::serveFile(request, *serverConfig);
    client.setWriteBuffer(response.toString());
}

The server resolves the virtual host, applies location rules, detects CGI requests, and delegates either to CGIHandler or the static FileServer to populate the response buffer returned to the client.

Configuration

• webserv.conf ships with two server blocks demonstrating static hosting, file uploads, CGI execution, and a /stop administrative endpoint.
• YAML configuration is also supported; files ending in .yml/.yaml are parsed automatically.
• Locations can enable CGI with cgi_extension, customize roots, index files, autoindex, upload destinations, and more.

Build & Run

make            # build all targets into ./webserv
./webserv webserv.conf

Point your browser (or curl) to http://localhost:8080 to explore the static demo and CGI samples in cgi-bin/.

Logging & Monitoring

The Logger utility prints timestamped, colorized events. Adjust verbosity with:

Logger::setLevel(DEBUG);

Sample log excerpt captured during a local run (ANSI colors removed for clarity):

Use these logs to trace request lifecycles, confirm CGI execution, and diagnose configuration issues.

Project Layout

Makefile         # Build entry point
stress_test.sh   # High-level curl stress scenarios
webserv          # Compiled server binary
webserv.conf     # Default configuration (NGINX syntax)
cgi-bin/         # Sample CGI scripts (PHP, Python)
errors/          # Custom HTML error pages
src/             # C++ sources (core, http, config, cgi, utils)
static/          # Public static assets and HTML demos
uploads/         # Destination for file uploads

Testing & Diagnostics

• Stress testing: ./stress_test.sh drives heavy concurrent GET/POST mix; add siege or wrk for deeper benchmarks.
• Memory analysis: valgrind --leak-check=full --track-fds=yes ./webserv webserv.conf
• Manual smoke tests: curl -v http://localhost:8080/, curl -v http://localhost:8080/cgi-bin/hello.php, and curl -F "file=@README.md" http://localhost:8080/upload.

Dependencies

The project depends only on the C++ standard library and POSIX sockets/epoll. No third-party packages are required.