Rack middleware that makes sure requests don't get a dead Sequel connection

sequel_reconnector.rb

require "sequel/extensions/connection_validator"
# https://github.com/jeremyevans/sequel/blob/master/lib/sequel/extensions/connection_validator.rb

module Rack
  class SequelConnectionValidator
    def initialize(app, db)
      @app = app
      @db  = db
      
      @db.extension(:connection_validator)
      @db.pool.connection_validation_timeout = -1
    end
    
    def call(env)
      @db.synchronize do
        @app.call(env)
      end
    end
  end
end