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WEB server toolkit.

WEBrick is an HTTP server toolkit that can be configured as an HTTPS server, a proxy server, and a virtual-host server. WEBrick features complete logging of both server operations and HTTP access. WEBrick supports both basic and digest authentication in addition to algorithms not in RFC 2617.

A WEBrick server can be composed of multiple WEBrick servers or servlets to provide differing behavior on a per-host or per-path basis. WEBrick includes servlets for handling CGI scripts, ERB pages, Ruby blocks and directory listings.

WEBrick also includes tools for daemonizing a process and starting a process at a higher privilege level and dropping permissions.

Starting an HTTP server

To create a new WEBrick::HTTPServer that will listen to connections on port 8000 and serve documents from the current user’s public_html folder:

require 'webrick'

root = File.expand_path '~/public_html'
server = WEBrick::HTTPServer.new :Port => 8000, :DocumentRoot => root

To run the server you will need to provide a suitable shutdown hook as starting the server blocks the current thread:

trap 'INT' do server.shutdown end

server.start

Custom Behavior

The easiest way to have a server perform custom operations is through WEBrick::HTTPServer#mount_proc. The block given will be called with a WEBrick::HTTPRequest with request info and a WEBrick::HTTPResponse which must be filled in appropriately:

server.mount_proc '/' do |req, res|
  res.body = 'Hello, world!'
end

Remember that server.mount_proc must precede server.start.

Servlets

Advanced custom behavior can be obtained through mounting a subclass of WEBrick::HTTPServlet::AbstractServlet. Servlets provide more modularity when writing an HTTP server than mount_proc allows. Here is a simple servlet:

class Simple < WEBrick::HTTPServlet::AbstractServlet
  def do_GET request, response
    status, content_type, body = do_stuff_with request

    response.status = 200
    response['Content-Type'] = 'text/plain'
    response.body = 'Hello, World!'
  end
end

To initialize the servlet you mount it on the server:

server.mount '/simple', Simple

See WEBrick::HTTPServlet::AbstractServlet for more details.

Virtual Hosts

A server can act as a virtual host for multiple host names. After creating the listening host, additional hosts that do not listen can be created and attached as virtual hosts:

server = WEBrick::HTTPServer.new # ...

vhost = WEBrick::HTTPServer.new :ServerName => 'vhost.example',
                                :DoNotListen => true, # ...
vhost.mount '/', ...

server.virtual_host vhost

If no :DocumentRoot is provided and no servlets or procs are mounted on the main server it will return 404 for all URLs.

HTTPS

To create an HTTPS server you only need to enable SSL and provide an SSL certificate name:

require 'webrick'
require 'webrick/https'

cert_name = [
  %w[CN localhost],
]

server = WEBrick::HTTPServer.new(:Port => 8000,
                                 :SSLEnable => true,
                                 :SSLCertName => cert_name)

This will start the server with a self-generated self-signed certificate. The certificate will be changed every time the server is restarted.

To create a server with a pre-determined key and certificate you can provide them:

require 'webrick'
require 'webrick/https'
require 'openssl'

cert =