riemann-maintenance-mode

(defn maintenance-mode?
  "Is Riemann currently in maintenance mode?"
  []
  ; Take an expression representing a query for maintenance mode
  (->> '(and (= :host nil)
             (= :service "maintenance-mode"))
       ; Search the current Riemann core's index for any matching events
       (riemann.index/search (:index @core))
       ; Take the first match
       first
       ; Find its state
       :state
       ; Is it the string "active"?
       (= "active")))