How to add code to set headers to a simple ruby webrick command line?

Question

When I need a test web server that can serve a few files from some directory, I really like the simplicity of

ruby -run -e httpd . -p 8888

then browse to localhost:8888 .

However, sometimes I'd like to add a tiny little bit to that, for example, set a specific mime type for a specific extension (I can edit /usr/lib/ruby/2.3.0/webrick/httputils.rb , but I'd rather not mess with system files), or add an Expires: header.

It seems like adding a header isn't that complicated, for example, looking at https://www.thecodingforums.com/threads/setting-expires-http-response-header.822995/ .

However, I have zero knowledge about ruby, so I have no clue about how to add that to my command line. I guess it's just "create a file that has a subclass, pull it in, and tell ruby to use the subclass", but well .. that answer is 3 steps beyond me.

So, I'd be grateful for an answer that says "Put this into a file, then add that to your command line", with copy/pasteable examples of this and that .

Answer 1

Ok. Put this into a file server.rb for example:

require 'webrick'                                                                                                          

class Server < WEBrick::HTTPServer                                                                                         
  def service(req, res)                                                                                                    
    super                                                                                                                  
    one_hour = 60 * 60                                                                                                     
    t = Time.now.gmtime + one_hour
    res['Expires'] = t.strftime("%a, %d %b %Y %H:%M:%S GMT")
  end                                                                                                                      
end                                                                                                                        

root = File.expand_path('.')                                                                                               
server = Server.new(Port: 8000, DocumentRoot: root)                                                                        

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

server.start 

Then run this in console:

ruby server.rb

It will serve files list from current directory.