机架中间件全局中间件

Question

有没有人能解释一下这段代码是如何工作的，尤其是日志过滤器部分。我想从rack文件中分配log_attributes_filter，在这里我调用use MongodbLogger::RackMiddleware，怎么做？

# Rack middleware for mounted rack app (e.g Grape)
module MongodbLogger
  class RackMiddleware
    @@log_attributes_filter = nil

    def self.log_attributes_filter=(filter)
      @@log_attributes_filter = filter
    end

    def initialize(app)
      @app = app
    end

    def call(env)
      request = ::Rack::Request.new env
      path = request.path.split('/')
      log_attrs = {
        params:     request.params
      }

      log_attrs = @@log_attributes_filter.call(log_attrs) if @@log_attributes_filter

      logger.mongoize(log_attrs) do
        return @app.call(env)
      end
    end
  end
end

以前我只是简单地将它用作use MongodbLogger::RackMiddleware，但现在我想过滤一些参数，我应该如何正确地分配@@log_attributes_filter

Answer 1

找到了一种方法。

  use MongodbLogger::RackMiddleware
  MongodbLogger::RackMiddleware.log_attributes_filter = lambda do |request|
    begin
      request[:params]["Password"] = "[FILTERED]"
      request
    rescue
      request
    end
  end