Added Telegram plugin (#4269)

scripts/plugins/endpoints/telegram_alert_endpoint/alert_endpoints/telegram.lua

@@ -0,0 +1,177 @@
+--
+-- (C) 2020 - ntop.org
+--
+
+--
+
+require "lua_utils"
+local json = require "dkjson"
+local alert_utils = require "alert_utils"
+
+local endpoint_key = "telegram_alert_endpoint"
+
+local telegram = {
+   name = "Telegram", -- A human readable name which will be shown in the UI
+
+   -- (1) Endpoint (see )
+   conf_params = {
+      -- Define here the endpoint parameters used in the endpoint GUI
+      { param_name = "telegram_token" }, -- Telegram token
+   },
+   
+   conf_template = {
+      plugin_key = endpoint_key, -- Unique string key
+
+      -- Filename of the GUI block for this endpoint
+      -- relative pathname to telegram_alert_endpoint/templates/telegram_endpoint.template
+      template_name = "telegram_endpoint.template" 
+   },
+
+
+   -- (2) Recipient
+   recipient_params = {
+      -- Define here the endpoint parameters used in the recipient GUI
+      { param_name = "telegram_channel"}, -- Name of the channel
+   },
+   recipient_template = {
+      plugin_key = endpoint_key, -- Unique string key
+
+      template_name = "telegram_recipient.template"
+   },
+}
+
+-- ##############################################
+
+-- How often this script will be called (in seconds) for checking if there are messages to be processes
+telegram.EXPORT_FREQUENCY = 5
+
+-- ##############################################
+
+-- @brief Returns the desided formatted output for recipient params
+function telegram.format_recipient_params(recipient_params)
+   return string.format("(%s)", telegram.name)
+end
+
+-- ##############################################
+
+-- Extract settings from recipients and place them on a simple datastructure
+local function readSettings(recipient)
+   local settings = {
+      -- Endpoint
+     url = "https://api.telegram.org/bot" .. recipient.endpoint_conf.telegram_token .. "/sendMessage?chat_id=" .. recipient.recipient_params.telegram_channel .. "&text=", -- this information is coming from the endpoint configuration recipient.endpoint_conf. ...
+  }
+
+  return settings
+end
+
+-- ##############################################
+
+-- Function called whenever a message has to be sent out to telegram
+function telegram.sendMessage(message_body, settings)
+   local rc = false
+   local retry_attempts = 3
+
+   if isEmptyString(settings.url) then
+      return false
+   end   
+
+   while retry_attempts > 0 do
+
+      -- In this case "httpGet" method is needed
+
+      local post_rc = ntop.httpGet(settings.url .. message_body)
+
+      if(post_rc and (post_rc.RESPONSE_CODE == 200)) then 
+	      rc = true
+	      break 
+      end
+      
+      retry_attempts = retry_attempts - 1
+   end
+
+   return rc
+end
+
+-- ##############################################
+
+local function formatTelegramMessage(alert)
+   local msg = alert_utils.formatAlertNotification(alert, {nohtml=true, add_cr=true, no_bracket_around_date=true})
+   
+   return(msg)
+end
+
+-- ##############################################
+
+-- Function called periodically to process queued alerts to be delivered via telegram
+function telegram.dequeueRecipientAlerts(recipient, budget, high_priority)
+  local start_time = os.time()
+  local sent = 0
+  local more_available = true
+  local budget_used = 0
+  local settings = readSettings(recipient)
+  local max_alerts_per_request = 1 -- collapse up to X alerts per request
+
+  -- Dequeue alerts up to budget x max_alerts_per_request
+  -- Note: in this case budget is the number of email to send
+  while budget_used <= budget and more_available do
+    local diff = os.time() - start_time
+    if diff >= 5 then
+      break
+    end
+
+    -- Dequeue max_alerts_per_request notifications
+    local notifications = {}
+    for i=1, max_alerts_per_request do
+       local notification = ntop.recipient_dequeue(recipient.recipient_id, high_priority)
+       if notification then 
+	  notifications[#notifications + 1] = notification
+       else
+	  break
+       end
+    end
+
+    if not notifications or #notifications == 0 then
+      more_available = false
+      break
+    end
+
+    local alerts = {}
+
+    for _, json_message in ipairs(notifications) do
+       table.insert(alerts, formatTelegramMessage(json.decode(json_message)))       
+    end
+
+    if not telegram.sendMessage(table.concat(alerts, "\n"), settings) then
+      return {success=false, error_message="Unable to send alerts to the telegram"}
+    end
+
+    -- Remove the processed messages from the queue
+    budget_used = budget_used + #notifications
+    sent = sent + 1
+  end
+
+  return {success = true, more_available = more_available}
+end
+
+-- ##############################################
+
+-- This is a testing function invoked by the web GUI whenever a test message has to be sent out
+
+function telegram.runTest(recipient)
+  local message_info
+
+  local settings = readSettings(recipient)
+
+  local success = telegram.sendMessage("test", settings)
+
+  if not success then
+    message_info = i18n("telegram_alert_endpoint.telegram_send_error")
+  end
+
+  return success, message_info
+end
+
+-- ##############################################
+
+return telegram
+