HASH32 Engineering

Ruby one-liner server

November 26, 2018 | 4 Minute Read

To quickly serve static files in a local development machine, we have used the handy python one-liner to run SimpleHTTPServer. There is a ruby equivalent to it.

Serve static files

I use this usual goto command, which runs python.

python -m SimpleHTTPServer

There is an equivalent ruby one-liner, which runs WEBrick.

ruby -run -e httpd

This is a pretty powerful server. WEBRick can run a small site/blog without much issues. Read about Richard Schneeman’s experiences here.

Breaking it down

Running ruby --help gives the various command line options. The ones in use here are:

-e 'command'    one line of script. Several -e's allowed.
-rlibrary       require the library before executing your script

By some clever file naming by the ruby devs, there is a library in the ruby source named un.rb(view source).

This allows to run common unix commands, as this file defines ruby functions for them. For example the following:

ruby -run -e cp -- [OPTION] SOURCE DEST
ruby -run -e touch -- [OPTION] FILE
ruby -run -e mkdir -- [OPTION] DIRS

It also has an httpd function which runs WEBRick! And it has a list of options as well! You can even configure a ssl certificate if required!

ruby -run -e httpd -- [OPTION] DocumentRoot

--bind-address=ADDR         address to bind
--port=NUM                  listening port number
--max-clients=MAX           max number of simultaneous clients
--temp-dir=DIR              temporary directory
--do-not-reverse-lookup     disable reverse lookup
--request-timeout=SECOND    request timeout in seconds
--http-version=VERSION      HTTP version
--server-name=NAME          name of the server host
--server-software=NAME      name and version of the server
--ssl-certificate=CERT      The SSL certificate file for the server
--ssl-private-key=KEY       The SSL private key file for the server certificate
-v                          verbose

If you want to modify other options, that WEBrick provides, you can customize as required with a .rb script. Here I’m adding a new mime type to the WEBrick server.

require 'webrick'

mime_types = WEBrick::HTTPUtils::DefaultMimeTypes
mime_types.store 'wasm', 'application/wasm'

root = File.expand_path('.')

server = WEBrick::HTTPServer.new(
  Port: 8000,
  DocumentRoot: root,
  MimeTypes: mime_types

trap('INT') { server.shutdown } # Ctrl-C to stop


There are plenty of options. Hack away with WEBrick!

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