Adds plugin user script to write system alert timeseries

scripts/plugins/timeseries/user_scripts/system/alerts_ts.lua

@@ -0,0 +1,46 @@
+--
+-- (C) 2019-20 - ntop.org
+--
+
+local ts_utils = require("ts_utils_core")
+local user_scripts = require("user_scripts")
+local system_utils = require("system_utils")
+
+local script = {
+  -- Script category
+  category = user_scripts.script_categories.system,
+
+  -- This module is enabled by default
+  default_enabled = true,
+
+  -- No default configuration is provided
+  default_value = {},
+
+  -- See below
+  hooks = {},
+
+  gui = {
+    i18n_title = "alerts_dashboard.alerts_ts",
+    i18n_description = "alerts_dashboard.alerts_ts_description",
+  },
+}
+
+-- ##############################################
+
+function script.hooks.min(params)
+   if params.ts_enabled then
+      local system_host_stats = system_utils.systemHostStats()
+
+      ts_utils.append("process:num_alerts",
+		      {
+			 ifid = getSystemInterfaceId(),
+			 dropped_alerts = system_host_stats.dropped_alerts or 0,
+			 written_alerts = system_host_stats.written_alerts or 0,
+			 alerts_queries = system_host_stats.alerts_queries or 0
+		      }, when, verbose)
+   end
+end
+
+-- ##############################################
+
+return script