Reworked shell script execution with runtime alert values

scripts/plugins/endpoints/shell_alert_endpoint/alert_endpoints/shell.lua

@@ -64,46 +64,85 @@ end
 
 -- ##############################################
 
-function shell.sendMessage(alerts, settings)
-  if isEmptyString(settings.path) then
-    return false
-  end
- 
+function expandArguments(cmd, myalert)
+   alert = myalert -- Not sure why we need a non-local variable
+   
+   -- Search all alert.* strings
+   for word in string.gmatch(cmd, 'alert.[^,%s]+') do
+      local func, err = load("return "..word)
+
+      if(func) then
+	 local ok, res = pcall(func)
+
+	 if(ok) then
+	    -- print("Found "..word)
+	    cmd = cmd:gsub(word, res)
+	 else
+	    -- print("Execution error:", res)
+	 end
+      end
+   end
+
+   return(cmd)
+end
+
+-- ##############################################
+
+function shell.runScript(alerts, settings)
+   local where = { "/usr/share/ntopng/scripts/shell/", dirs.installdir.."/scripts/shell/" }
+   local fullpath = nil
+   local do_debug = false
+   
+   for _,p in ipairs(where) do
+      local path = p .. settings.path
+
+      if(do_debug) then tprint("Checking "..path) end
+      
+      if(ntop.exists(path)) then
+	 fullpath = path
+	 break
+      end
+   end
+
+   if(fullpath == nil) then
+      if(do_debug) then tprint("Not found: "..settings.path.." ("..dirs.installdir ..")") end
+      return(false)
+   end
+
   for key, alert in ipairs(alerts) do
     -- Executing the script
-    local exec_script = settings.path .. " " .. settings.options
+    local exec_script = fullpath .. " " .. settings.options
 
-    os.execute(exec_script)
+    if(do_debug) then
+       -- tprint(alert)
+       tprint("[Before] "..exec_script)
+    end
+
+    exec_script = expandArguments(exec_script, alert)
+    if(do_debug) then tprint("[After] "..exec_script) end
+
+    -- Mask output
+    os.execute(exec_script.." > /dev/null")
 
     -- Storing an alert-notice in regard of the shell script execution
     -- for security reasons
     local entity_info = alerts_api.processEntity("ntopng")
     local type_info = alert_consts.alert_types.alert_shell_script_executed.create(
-      alert_consts.alert_severities.notice,
-      exec_script,
-      alert_consts.alertTypeLabel(alert["alert_type"], true)
+       alert_consts.alert_severities.notice,
+       exec_script,
+       alert_consts.alertTypeLabel(alert["alert_type"], true)
     )
 
     alerts_api.store(entity_info, type_info)
-  end
+  end -- for
+
+  return true
 end
 
 -- ##############################################
 
 function shell.dequeueRecipientAlerts(recipient, budget, high_priority)
-  local full_path
   local settings = recipient2sendMessageSettings(recipient)
-
-  -- Checking if the script still exist for security reasons
-  if ntop.exists("/usr/share/ntopng/" .. settings.path) then
-    full_path = "/usr/share/ntopng/" .. settings.path
-  elseif ntop.exists("scripts/shell/" .. settings.path) then
-    full_path = "scripts/shell/" .. settings.path
-  else
-    return {success=false, error_message="- unable to execute the script"}
-  end
-
-  settings.path = full_path
   local start_time = os.time()
   local sent = 0
   local more_available = true
@@ -123,7 +162,7 @@ function shell.dequeueRecipientAlerts(recipient, budget, high_priority)
     local notifications = {}
     for i = 1, MAX_ALERTS_PER_REQUEST do
        local notification = ntop.recipient_dequeue(recipient.recipient_id, high_priority)
-       if notification then 
+       if notification then
 	  notifications[#notifications + 1] = notification
        else
 	  break
@@ -142,7 +181,9 @@ function shell.dequeueRecipientAlerts(recipient, budget, high_priority)
       table.insert(alerts, alert)
     end
 
-    shell.sendMessage(alerts, settings)
+    if(shell.runScript(alerts, settings) == false) then
+       return { success=false, error_message="- unable to execute the script" }
+    end
 
     -- Remove the processed messages from the queue
     budget_used = budget_used + #notifications
@@ -158,7 +199,7 @@ function shell.runTest(recipient)
   local message_info
 
   local settings = recipient2sendMessageSettings(recipient)
-  local success = shell.sendMessage({}, settings)
+  local success = shell.runScript({}, settings)
 
   if not success then
     message_info = i18n("shell_alert_endpoint.shell_send_error")
@@ -170,4 +211,3 @@ end
 -- ##############################################
 
 return shell
-