# File lib/rails-installer/web-servers.rb, line 33
      def self.start(installer, foreground)
        args = {}
        args['-p'] = installer.config['port-number']
        args['-a'] = installer.config['bind-address']
        args['-e'] = installer.config['rails-environment']
        args['-d'] = foreground
        args['-P'] = pid_file(installer)
        args['--prefix'] = installer.config['url-prefix']

        # Remove keys with nil values
        args.delete_if {|k,v| v==nil}

        args_array = args.to_a.flatten.map {|e| e.to_s}
        args_array = ['mongrel_rails', 'start', installer.install_directory] + args_array
        installer.message "Starting #{installer.app_name.capitalize} on port #{installer.config['port-number']}"
        in_directory installer.install_directory do
          system(args_array.join(' '))
        end
      end