Checking Limits Without Incrementing? #599

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1. 6f6d6172 commented on Dec 1, 2022

   

   6f6d6172

   on Dec 1, 2022

   Author

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   Through a series of monkeypatches, I've achieved the behavior I'm looking for. Hopefully this can do a decent job of explaining my usecase. This allows me to use it in a controller like like

     def show
       if limiter.at_limit?(request)
         @warning_message = "Attempts exceeded."
         @challenge = new_captcha_form
       end
     end
   
     def create
       if limiter.matched_by?(request)
         validate_captcha
       end
   
       rest_of_the_action
     end
   
     def limiter
       limiter = Rack::Attack.track("requests from bucket", limit: 5, period: 3600) do |req|
         bucket
       end
     end

   monkeypatch:

   Rack::Attack::Configuration.class_eval do
     # nop'd because otherwise all Rack::Attack::Throttles are incremented
     # even if the gated functionality is never exercised
     def tracked?(request)
     end
   end
   
   Rack::Attack::Cache.class_eval do
     def get_count(unprefixed_key, period)
       enforce_store_presence!
       enforce_store_method_presence!(:read)
   
       key, expires_in = key_and_expiry(unprefixed_key, period)
       result = store.read(key)
       result || 0
     end
   
   end
   
   Rack::Attack::Track.class_eval do
     def at_limit?(request)
       filter.at_limit?(request)
     end
   end
   
   Rack::Attack::Throttle.class_eval do
     def at_limit?(request)
       discriminator = discriminator_for(request)
       return false unless discriminator
   
       current_period  = period_for(request)
       current_limit   = limit_for(request)
       count           = cache.get_count("#{name}:#{discriminator}", current_period)
       
       count > current_limit
     end
   end
2. rack

   locked and limited conversation to collaborators on Dec 12, 2022
3. grzuy

   converted this issue into a discussion #602 on Dec 12, 2022