Reworks alert counters (WIP)

Alert counters are now kept in sync only for engaged alerts.
Each host will show the current number of engaged alerts.
This alleviates the complexity of constantly keep the numbers
synchronized with the database.

Todo: see how to handle counters for flow alerts and past alerts.

scripts/lua/modules/alert_utils.lua

@@ -219,7 +219,7 @@ end
 
 function delete_alert_configuration(alert_source, ifname)
    local ifid = getInterfaceId(ifname)
-   local alert_level  = 1 -- alert_level_warning
+   local alert_level  = 2 -- alert_level_error
    local alert_type   = 2 -- alert_threshold_exceeded
    local is_host = false
    delete_re_arming_alerts(alert_source, ifid)
@@ -251,16 +251,15 @@ function delete_alert_configuration(alert_source, ifname)
 
    if is_host == true then
       interface.refreshNumAlerts(alert_source)
-   else
-      interface.refreshNumAlerts()
    end
+   interface.refreshNumAlerts()
 end
 
 function refresh_alert_configuration(alert_source, ifname, timespan, alerts_string)
    if tostring(alerts_string) == nil then return nil end
    if is_allowed_timespan(timespan) == false then return nil end
    local ifid = getInterfaceId(ifname)
-   local alert_level  = 1 -- alert_level_warning
+   local alert_level  = 2 -- alert_level_error
    local alert_type   = 2 -- alert_threshold_exceeded
    local is_host = false
    -- check if we are processing a pair ip-vlan such as 192.168.1.0@0
@@ -307,9 +306,8 @@ function refresh_alert_configuration(alert_source, ifname, timespan, alerts_stri
 
    if is_host == true then
       interface.refreshNumAlerts(alert_source)
-   else
-      interface.refreshNumAlerts()
    end
+   interface.refreshNumAlerts()
 end
 
 function check_host_alert(ifname, hostname, mode, key, old_json, new_json)
@@ -323,7 +321,7 @@ function check_host_alert(ifname, hostname, mode, key, old_json, new_json)
         print("<p>--------------------------------------------<p>\n")
     end
 
-   local alert_level  = 1 -- alert_level_warning
+   local alert_level  = 2 -- alert_level_error
    local alert_type   = 2 -- alert_threshold_exceeded
    local alert_status     -- to be set later
 
@@ -403,7 +401,7 @@ function check_network_alert(ifname, network_name, mode, key, old_table, new_tab
         tprint(old_table)
     end
 
-   local alert_level = 1 -- alert_level_warning
+   local alert_level = 2 -- alert_level_error
    local alert_status = 1 -- alert_on
    local alert_type = 2 -- alert_threshold_exceeded
 
@@ -481,7 +479,7 @@ function check_interface_alert(ifname, mode, old_table, new_table)
         print("check_interface_alert("..ifname..", "..mode..")<br>\n")
     end
 
-    local alert_level  = 1 -- alert_level_warning
+    local alert_level  = 2 -- alert_level_error
     local alert_status = 1 -- alert_on
     local alert_type   = 2 -- alert_threshold_exceeded
 
@@ -803,12 +801,67 @@ function performAlertsQuery(statement, what, opts)
 
    -- trigger counters refresh
    if trimSpace(statement:lower()) == "delete" then
-      interface.refreshNumAlerts(true)
+      -- keep counters in sync only for engaged alerts
+      if what == "engaged" then
+	 refreshHostsEngagedAlertsCounters()
+      end
    end
 
    return res
 end
 
+-- #################################
+function refreshHostsEngagedAlertsCounters(host_vlan)
+   local hosts
+   
+   if isEmptyString(host_vlan) == false then
+      hosts[host_vlan:gsub("@0","")] = {updated = false}
+   else 
+      hosts = interface.getHostsInfo(false --[[ no details --]])
+      hosts = hosts["hosts"]
+   end
+
+   for k, v in pairs(hosts) do
+      if v["num_alerts"] > 0 then
+	 hosts[k] = {updated = false}
+      else
+	 hosts[k] = nil
+      end
+   end
+
+   local res = interface.queryAlertsRaw(true, "select alert_entity_val, count(*) cnt",
+					"where alert_entity="..alertEntity("host")
+					   .. " group by alert_entity_val having cnt > 0")
+
+   if res == nil then res = {} end
+
+   -- update the hosts that actually have engaged alerts
+   for _, k in pairs(res) do
+      local entity_val = k["alert_entity_val"]
+      local sp = split(entity_val, "@")
+      local host = sp[1]
+      local vlan = tonumber(sp[2])
+      if vlan == 0 then
+	 entity_val = host -- no vlan in the key if vlan is zero
+      end
+
+      interface.refreshNumAlerts(host, vlan, tonumber(k["cnt"]))
+
+      if hosts[entity_val] ~= nil then
+	 hosts[entity_val]["updated"] = true
+      end
+   end
+
+   -- finally update the hosts that no longer have engaged alerts
+   for k, v in pairs(hosts) do
+      if v["updated"] == false then
+	 interface.refreshNumAlerts(k, nil, 0);
+      end
+   end
+
+   interface.refreshNumAlerts()
+end
+
 -- #################################
 
 function getNumAlerts(what, options)
@@ -968,6 +1021,12 @@ function drawAlertSourceSettings(alert_source, delete_button_msg, delete_confirm
    local num_engaged_alerts, num_past_alerts, num_flow_alerts = 0,0,0
    local tab = _GET["tab"]
 
+   local descr = alert_functions_description
+   if alert_source:match("/") then
+      descr = network_alert_functions_description
+   end
+   
+
    print('<ul class="nav nav-tabs">')
 
    local function printTab(tab, content, sel_tab)
@@ -1031,7 +1090,7 @@ function drawAlertSourceSettings(alert_source, delete_button_msg, delete_confirm
          delete_alert_configuration(alert_source, ifname)
          alerts = nil
       else
-         for k,_ in pairs(alert_functions_description) do
+         for k,_ in pairs(descr) do
        value    = _GET["value_"..k]
        operator = _GET["operator_"..k]
 
@@ -1093,7 +1152,7 @@ function drawAlertSourceSettings(alert_source, delete_button_msg, delete_confirm
          print('<input type=hidden name="'..param..'" value="'..value..'">\n')
       end
 
-      for k,v in pairsByKeys(alert_functions_description, asc) do
+      for k,v in pairsByKeys(descr, asc) do
          print("<tr><th>"..k.."</th><td>\n")
          print("<select name=operator_".. k ..">\n")
          if((vals[k] ~= nil) and (vals[k][1] == "gt")) then print("<option selected=\"selected\"") else print("<option ") end