Implements network alerts

scripts/callbacks/interface/alerts/network/check.lua

@@ -0,0 +1,49 @@
+--
+-- (C) 2019 - ntop.org
+--
+
+local check = {}
+
+-- #################################################################
+
+local function cached_val_key(metric_name, granularity_num)
+   return string.format("%s:%s", metric_name, granularity_num)
+end
+
+-- #################################################################
+
+local function delta_val(metric_name, granularity_num, curr_val)
+   local key = cached_val_key(metric_name, granularity_num)
+
+   -- Read cached value and purify it
+   local prev_val = network.getCachedAlertValue(key, granularity_num)
+   prev_val = tonumber(prev_val) or 0
+
+   -- Save the value for the next round
+   network.setCachedAlertValue(key, tostring(curr_val), granularity_num)
+
+   -- Compute the delta
+   return curr_val - prev_val
+end
+
+-- #################################################################
+
+function check.egress(metric_name, info, granularity, granularity_num)
+   return delta_val(metric_name, granularity_num, info["egress"])
+end
+
+-- #################################################################
+
+function check.ingress(metric_name, info, granularity, granularity_num)
+   return delta_val(metric_name, granularity_num, info["ingress"])
+end
+
+-- #################################################################
+
+function check.inner(metric_name, info, granularity, granularity_num)
+   return delta_val(metric_name, granularity_num, info["inner"])
+end
+
+-- #################################################################
+
+return check