Basic static file server in NodeJS

Question

I\'m trying to create a static file server in nodejs more as an exercise to understand node than as a perfect server. I\'m well aware of projects like Connect and node-stati

Answer 1

I like understanding what's going on under the hood as well.

I noticed a few things in your code that you probably want to clean up:

• It crashes when filename points to a directory, because exists is true and it tries to read a file stream. I used fs.lstatSync to determine directory existence.

• It isn't using the HTTP response codes correctly (200, 404, etc)

• While MimeType is being determined (from the file extension), it isn't being set correctly in res.writeHead (as stewe pointed out)

• To handle special characters, you probably want to unescape the uri

• It blindly follows symlinks (could be a security concern)

Given this, some of the apache options (FollowSymLinks, ShowIndexes, etc) start to make more sense. I've update the code for your simple file server as follows:

var http = require('http'),
    url = require('url'),
    path = require('path'),
    fs = require('fs');
var mimeTypes = {
    "html": "text/html",
    "jpeg": "image/jpeg",
    "jpg": "image/jpeg",
    "png": "image/png",
    "js": "text/javascript",
    "css": "text/css"};

http.createServer(function(req, res) {
  var uri = url.parse(req.url).pathname;
  var filename = path.join(process.cwd(), unescape(uri));
  var stats;

  try {
    stats = fs.lstatSync(filename); // throws if path doesn't exist
  } catch (e) {
    res.writeHead(404, {'Content-Type': 'text/plain'});
    res.write('404 Not Found\n');
    res.end();
    return;
  }


  if (stats.isFile()) {
    // path exists, is a file
    var mimeType = mimeTypes[path.extname(filename).split(".").reverse()[0]];
    res.writeHead(200, {'Content-Type': mimeType} );

    var fileStream = fs.createReadStream(filename);
    fileStream.pipe(res);
  } else if (stats.isDirectory()) {
    // path exists, is a directory
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.write('Index of '+uri+'\n');
    res.write('TODO, show index?\n');
    res.end();
  } else {
    // Symbolic link, other?
    // TODO: follow symlinks?  security?
    res.writeHead(500, {'Content-Type': 'text/plain'});
    res.write('500 Internal server error\n');
    res.end();
  }

}).listen(1337);