Migrates alerts to an object-oriented implementation

scripts/lua/modules/alert_definitions/alert_unexpected_dns.lua

@@ -1,23 +1,56 @@
+--
+-- (C) 2019-20 - ntop.org
+--
+
+-- ##############################################
+
 local alert_keys = require "alert_keys"
+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 function createUnexpectedDNS(client_ip, server_ip)
-    local built = {
-       alert_type_params = {
-	  client_ip = client_ip,
-	  server_ip = server_ip
-       }
-    }
+local alert_unexpected_dns_server = classes.class(alert)
 
-    return built
+-- ##############################################
+
+alert_unexpected_dns_server.meta = {
+   status_key = status_keys.ntopng.status_unexpected_dns_server,
+   alert_key = alert_keys.ntopng.alert_unexpected_dns_server,
+   i18n_title = "unexpected_dns.alert_unexpected_dns_title",
+   icon = "fas fa-exclamation",
+}
+
+-- ##############################################
+
+-- @brief Prepare an alert table used to generate the alert
+-- @param one_flow_param The first alert param
+-- @param another_flow_param The second alert param
+-- @return A table with the alert built
+function alert_unexpected_dns_server:init(client_ip, server_ip)
+   -- Call the parent constructor
+   self.super:init()
+
+   self.alert_type_params = {
+    client_ip = client_ip,
+    server_ip = server_ip
+   }
 end
 
--- #################################################
+-- #######################################################
 
-return {
-    alert_key = alert_keys.ntopng.alert_unexpected_dns_server,
-    i18n_title = "unexpected_dns.alert_unexpected_dns_title",
-    icon = "fas fa-exclamation",
-    creator = createUnexpectedDNS,
-}
+-- @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_unexpected_dns_server.format(ifid, alert, alert_type_params)
+    return(i18n("unexpected_dns.status_unexpected_dns_description", { server=alert_type_params.server_ip} ))
+end
+
+-- #######################################################
+
+return alert_unexpected_dns_server