Migrates alerts to an object-oriented implementation

scripts/lua/modules/alert_definitions/alert_external.lua

@@ -0,0 +1,85 @@
+--
+-- (C) 2019-20 - ntop.org
+--
+
+-- ##############################################
+
+local alert_keys = require "alert_keys"
+package.path = dirs.installdir .. "/scripts/lua/modules/?.lua;" .. package.path
+
+local status_keys = require "flow_keys"
+-- Import the classes library.
+local classes = require "classes"
+-- Make sure to import the Superclass!
+local alert = require "alert"
+
+-- ##############################################
+
+local alert_external = classes.class(alert)
+
+-- ##############################################
+
+alert_external.meta = {
+   status_key = status_keys.ntopng.status_external_alert,
+   alert_key = alert_keys.ntopng.alert_external,
+   i18n_title = "alerts_dashboard.external_alert",
+   icon = "fas fa-eye",
+}
+
+-- ##############################################
+
+-- @brief Prepare an alert table used to generate the alert
+-- @param alert_severity A severity as defined in `alert_severities`
+-- @param info A generic table decoded from a JSON originated at the external alert source
+-- @return A table with the alert built
+function alert_external:init(info)
+   -- Call the parent constructor
+   self.super:init()
+
+   self.alert_type_params = info
+end
+
+-- #######################################################
+
+local function formatIDSAlert(alert)
+   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
+
+-- #######################################################
+
+-- @brief Format an alert into a human-readable string
+-- @param ifid The integer interface id of the generated alert
+-- @param alert The alert description table, including alert data such as the generating entity, timestamp, granularity, type
+-- @param alert_type_params Table `alert_type_params` as built in the `:init` method
+-- @return A human-readable string
+function alert_external.format(flowstatus_info)
+   local res = i18n("alerts_dashboard.external_alert")
+
+   if not flowstatus_info then
+      return res
+   end
+
+   -- Available fields:
+   -- flowstatus_info.source (e.g. suricata)
+   -- flowstatus_info.severity_id (custom severity)
+   -- flowstatus_info.alert (alert metadata)
+
+   if flowstatus_info.source == "suricata" then
+      res = formatIDSAlert(flowstatus_info.alert)
+   end
+
+   return res
+end
+
+-- #######################################################
+
+return alert_external