Add support for a custom user defined alert endpoint script

scripts/lua/modules/alert_endpoints/sample.lua

@@ -0,0 +1,42 @@
+--
+-- (C) 2018 - ntop.org
+--
+
+require "lua_utils"
+local json = require "dkjson"
+
+local script = {}
+
+-- How often this script will be called (in seconds)
+script.EXPORT_FREQUENCY = 5
+
+-- The minimum severity for an alert
+script.DEFAULT_SEVERITY = "warning"
+
+function script.dequeueAlerts(queue)
+  while true do
+    local json_alert = ntop.lpopCache(queue)
+
+    if not json_alert then
+      break
+    end
+
+    local alert = json.decode(json_alert)
+
+    -- Print the alert on the console
+    tprint(alert)
+
+    if (alert.action == "engage") then
+      if (alertTypeRaw(alert.type) == "threshold_cross") and
+            (alert.alert_key == "min_active_local_hosts") then
+
+        -- Run a custom bash script
+        --os.execute("/tmp/my_script.sh")
+      end
+    end
+  end
+
+  return {success=true}
+end
+
+return script