email.clj

(ns examplecom.email
  "Riemann email alerting"
  (:require [riemann.email :refer :all]
            [riemann.common :refer :all]
            [clojure.string :as str]
            [clojure.pprint :as pp])
)

(def header "Monitoring alert from Riemann\n\n")
(def footer "This is an automated Riemann notification. Please do not reply.")

(defn lookup
  "Lookup events in the index"
  [host service]
  (riemann.index/lookup (:index @riemann.config/core) host service)
)

(defn round
  "Round numbers to 2 decimal places"
  [metric]
  (pp/cl-format nil "~,2f" metric)
)

(defn context
  "Add some contextual event data"
  [event]
  (str
    "Host context:\n"
    "  CPU\n"
    "    System: " (round (:metric (lookup (:host event) "cpu-0/cpu-system"))) "%\n"
    "    User:   " (round (:metric (lookup (:host event) "cpu-0/cpu-user"))) "%\n"
    "    IOWait: " (round (:metric (lookup (:host event) "cpu-0/cpu-wait"))) "%\n"
    "  Memory\n"
    "    Used:   " (:metric (lookup (:host event) "memory/memory-used")) " bytes.\n"
    "\n\n")
)

(defn format-subject
  "Format the email subject"
  [events]
  (apply format "Service %s in state %s on host %s" (str/join ", " (map :service events)) (str/join ", " (map :state events)) (map :host events))
)

(defn format-body
  "Format the email body"
  [events]
  (str/join "\n\n\n"
        (map
          (fn [event]
            (str
              header
              "At " (time-at (:time event)) "\n"
              "Host: " (:host event) "\n"
              "Service: " (:service event) "\n"
              "State: " (:state event) "\n"
              "Metric: " (if (ratio? (:metric event))
                (double (:metric event))
                (:metric event)) "\n"
              "Tags: [" (str/join ", " (:tags event)) "]"
              "\n\n"
              "Description: " (:description event)
              "\n\n"
              (if-not (riemann.streams/expired? event)
              (context event)
              footer)))
          events))
)

(def email (mailer {:from "[email protected]"
                    :subject (fn [events] (format-subject events))
                    :body (fn [events] (format-body events))
                    }))