Sinatra session / login example.

gistfile1.rb

require 'sinatra'

enable :sessions

before do
  if request.path != '/login' && !session[:logged_in]
    redirect '/login'
  end
end

get '/login' do
  # show a login page
endd

post '/login' do
  if params[:password] == "COOLBEANS"
    session[:logged_in] = true
  end
end

get '/members_area' do
  "SECRET"
end

get '/checkout' do
  "SECRET"
end

get '/profile' do
  "SECRET"
end