Massive cleanup of flow user scripts into callback_definitions

scripts/lua/modules/callback_definitions/flow/unexpected_ntp.lua

@@ -0,0 +1,54 @@
+--
+-- (C) 2019-21 - ntop.org
+--
+
+local user_scripts = require("user_scripts")
+local alerts_api = require "alerts_api"
+local alert_severities = require "alert_severities"
+local alert_consts = require("alert_consts")
+local flow_alert_keys = require "flow_alert_keys"
+
+local UNEXPECTED_PLUGINS_ENABLED_CACHE_KEY = "ntopng.cache.user_scripts.unexpected_plugins_enabled"
+
+-- #################################################################
+
+local script = {
+   -- Script category
+   category = user_scripts.script_categories.security,
+
+   -- This module is disabled by default
+   default_enabled = false,
+
+   -- This script is only for alerts generation
+   alert_id = flow_alert_keys.flow_alert_unexpected_ntp_server,
+
+   -- Specify the default value whe clicking on the "Reset Default" button
+   default_value = {
+      severity = alert_severities.error,
+      items = {},
+   },
+
+   gui = {
+      i18n_title        = "flow_callbacks.unexpected_ntp_title",
+      i18n_description  = "flow_callbacks.unexpected_ntp_description",
+
+      input_builder     = "items_list",
+      item_list_type    = "ip_address",
+      input_title       = "flow_callbacks.allowed_servers_title",
+      input_description = "flow_callbacks.allowed_servers_description",
+   }
+}
+
+-- #################################################################
+
+function script.onEnable(hook, hook_config)
+   -- Set a flag to indicate to the notifications system that an unexpected plugin
+   -- has been enabled
+   if isEmptyString(ntop.getCache(UNEXPECTED_PLUGINS_ENABLED_CACHE_KEY)) then
+      ntop.setCache(UNEXPECTED_PLUGINS_ENABLED_CACHE_KEY, "1")
+   end
+end
+
+-- #################################################################
+
+return script