 #   HUBOT_GRAFANA_S3_SECRET_ACCESS_KEY - Optional; Secret access key for S3
 #   HUBOT_GRAFANA_S3_PREFIX - Optional; Bucket prefix (useful for shared buckets)
 #   HUBOT_GRAFANA_S3_REGION - Optional; Bucket region (defaults to us-standard)
+#   HUBOT_USE_GRAFANA_IMAGES - true|false, whether to use grafana-images
+#   HUBOT_GRAFANA_IMAGES_HOST - The host where grafana images resides, e.g. 'http://grafana.example.com'
 #
 # Dependencies:
 #   "knox": "^0.9.2"


          # Fork here for S3-based upload and non-S3
          if (s3_bucket && s3_access_key && s3_secret_key)
            fetchAndUpload msg, title, imageUrl, link  
          else
            sendRobotResponse msg, title, imageUrl, link


  s3_prefix = process.env.HUBOT_GRAFANA_S3_PREFIX
  s3_region = 'us-standard'
  s3_region = process.env.HUBOT_GRAFANA_S3_REGION if process.env.HUBOT_GRAFANA_S3_REGION
  use_grafana_images = process.env.HUBOT_USE_GRAFANA_IMAGES
  grafana_images_host = if process.env.HUBOT_GRAFANA_IMAGES_HOST then process.env.HUBOT_GRAFANA_IMAGES_HOST else grafana_host

  # Get a specific dashboard with options
  robot.respond /(?:grafana|graph|graf) (?:dash|dashboard|db) ([A-Za-z0-9\-\:_]+)(.*)?/i, (msg) ->
