Add new alert no_exporter_activity

scripts/lua/modules/check_definitions/interface/no_exporter_activity.lua

@@ -0,0 +1,50 @@
+--
+-- (C) 2020 - ntop.org
+--
+
+local alerts_api = require("alerts_api")
+local alert_consts = require "alert_consts"
+local checks = require("checks")
+
+local script = {
+   -- Script category
+   category = checks.check_categories.internals,
+
+   default_enabled = true,
+   hooks = {},
+
+   severity = alert_consts.get_printable_severities().emergency,
+
+   gui = {
+      i18n_title        = "checks.no_exporter_activity_title",
+      i18n_description  = "checks.no_exporter_activity_description",
+   }
+}
+
+-- #################################################################
+
+local function check_exporter_activity(params)
+
+   if not interface.isZMQInterface() then
+      return -- Not a zmq interface, skip this check
+   end
+
+   --[[ Sample code for triggering alert:
+   local exporter = params.entity_info.name .. '@' .. "1.2.3.4"
+   params.entity_info.name = exporter 
+   local no_exporter_activity_type = alert_consts.alert_types.alert_no_exporter_activity.new(params.entity_info.name)
+   no_exporter_activity_type:set_info(params)
+   no_exporter_activity_type:trigger(params.alert_entity, nil, params.cur_alerts)
+   --]]
+
+   -- Engaged alerts should be automatically released on next iteration
+   --no_exporter_activity_type:release(params.alert_entity, nil, params.cur_alerts)
+end
+
+-- #################################################################
+
+script.hooks.min = check_exporter_activity
+
+-- #################################################################
+
+return script