Traffic Element Scripts¶

ntopng supports users scripts on the following traffic elements:

interface: a network interface of ntopng

network: a local network of ntopng

host: a local/remote host of ntopng

Hooks¶

Traffic element scripts are called periodically. The corresponding available hooks are:

min: called every minute

5mins: called every 5 minutes

hour: called every hour

day: called every day (at midnight)

all can be used to register to all the functions.

Example: Export active hosts list¶

The following example shows how to dump the active hosts list of ntopng every minute and send it to a remote server:

local user_scripts = require("user_scripts")
local json = require("dkjson")

-- Will be used to keep track of all the hosts
local hosts_list

local script = {
  hooks = {},
  gui = {
    i18n_title = "Test script",
    i18n_description = "A test script",
  }
}

-- #################################################################

-- Invocated when the script is loaded
function script.setup()
  -- Initialize an empty hosts list
  hosts_list = {}

  -- true: this script is enable
  return(true)
end

-- #################################################################

-- The minute callback
function script.hooks.min(params)
  table.insert(hosts_list, params.entity_info.ip)
end

-- #################################################################

-- Invocated when the script is unloaded
function script.teardown()
  local data = json.encode({when = os.time(), hosts = hosts_list})

  ntop.httpPost("https://example.com", data)
end

-- #################################################################

return(script)

The script can be saved as scripts/callbacks/interface/host/test.lua. It’s important to note that the script.setup() and script.teardown() functions are only executed once per script, whereas the hook functions (script.hooks.min in this case) will be executed once per host.

An easy way to limit the export to the local hosts is to add the local_hosts = true attribute to the script definition.