Adds migrated external_alert.lua

Fixes #4895

scripts/lua/modules/alert_definitions/external_alert.lua

@@ -0,0 +1,77 @@
+--
+-- (C) 2019-20 - ntop.org
+--
+
+local alert_keys = require "alert_keys"
+local status_keys = require "status_keys"
+-- Import the classes library.
+local classes = require "classes"
+-- Make sure to import the Superclass!
+local alert = require "alert"
+
+-- ##############################################
+
+local external_alert = classes.class(alert)
+
+-- ##############################################
+
+external_alert.meta = {
+   alert_key = alert_keys.ntopng.alert_external,
+   status_key = status_keys.ntopng.status_external_alert,
+   i18n_title = "alerts_dashboard.external_alert",
+   icon = "fas fa-eye",
+}
+
+-- #######################################################
+
+-- @brief Prepare an alert table used to generate the alert
+-- @param info A generic table decoded from a JSON originated at the external alert source
+-- @return A table with the alert built
+function external_alert:init(info)
+   -- Call the parent constructor
+   self.super:init()
+
+   self.alert_type_params = info
+end
+
+-- #######################################################
+
+local function formatIDSAlert(alert)
+   local alert_consts = require "alert_consts"
+
+   local signature = (alert and alert.signature)
+   local category = (alert and alert.category)
+   local signature_info = (signature and signature:split(" "));
+   local maker = (signature_info and table.remove(signature_info, 1))
+   local scope = (signature_info and table.remove(signature_info, 1))
+   local msg = (signature_info and table.concat(signature_info, " "))
+   if maker and alert_consts.ids_rule_maker[maker] then
+      maker = alert_consts.ids_rule_maker[maker]
+   end
+   return i18n("flow_details.ids_alert", { scope=scope, msg=msg, maker=maker })
+end
+
+-- #######################################################
+
+function external_alert.format(ifid, alert, alert_type_params)
+   local res = i18n("alerts_dashboard.external_alert")
+
+   if not alert_type_params then
+      return res
+   end
+
+   -- Available fields:
+   -- alert_type_params.source (e.g. suricata)
+   -- alert_type_params.severity_id (custom severity)
+   -- alert_type_params.alert (alert metadata)
+
+   if alert_type_params.source == "suricata" then
+      res = formatIDSAlert(alert_type_params.alert)
+   end
+
+   return res
+end
+
+-- #######################################################
+
+return external_alert