initial traffic recording module

scripts/lua/modules/recording_utils.lua

@@ -0,0 +1,94 @@
+--
+-- (C) 2014-18 - ntop.org
+--
+
+local dirs = ntop.getDirs()
+
+local recording_utils = {}
+
+recording_utils.n2disk_bin = "/usr/local/bin/n2disk"
+
+-- #################################
+
+local function executeWithOuput(c)
+   local f = assert(io.popen(c, 'r'))
+   local s = assert(f:read('*a'))
+   f:close()
+   return s
+end
+
+function recording_utils.isAvailable()
+   if not ntop.isWindows() and ntop.exists(recording_utils.n2disk_bin) then
+      return true
+   end
+   return false
+end
+
+function recording_utils.createConfig(ifname, params)
+   local filename = "/etc/n2disk/n2disk-"..ifname..".conf"
+
+   local defaults = {
+      path = "/storage",        -- Storage path
+      buffer_size = 4*1024,     -- Buffer size (MB)
+      max_file_size = 1024,     -- Max file length
+      max_disk_space = 10*1024, -- Max disk space (MB)
+      snaplen = 1536,           -- Capture length
+      writer_core = 0,          -- Writer thread affinity
+      reader_core = 1,          -- Reader thread affinity
+      indexer_cores = "2,3",    -- Indexer threads affinity
+   }
+
+   -- TODO 
+   -- - auto-tune cpu affinity based on the actual cpu and ntopng configuration
+   -- - auto-size max file size based on interface speed
+   -- - write the configuration file in a place where ntopng can write
+
+   if params.path == nil then -- mandatory parameters here
+      return false
+   end
+
+   local config = table.merge(defaults, params)
+
+   local f = io.open(filename, "w")
+
+   if not f then
+      return false
+   end
+
+   f:write("--interface="..config.interface.."\n")
+   f:write("--dump-directory="..config.path.."/n2disk/"..ifname.."\n")
+   f:write("--index\n")
+   f:write("--timeline-dir="..config.path.."/n2disk/"..ifname.."\n")
+   f:write("--buffer-len="..config.buffer_size.."\n")
+   f:write("--max-file-len="..config.max_file_size.."\n")
+   f:write("--disk-limit="..config.max_disk_space.."\n")
+   f:write("--snaplen="..config.snaplen.."\n")
+   f:write("--writer-cpu-affinity="..config.writer_core.."\n")
+   f:write("--reader-cpu-affinity="..config..reader_core."\n")
+   f:write("--compressor-cpu-affinity="..config..indexer_cores."\n")
+   f:write("--index-on-compressor-threads\n")
+
+   f:close()
+   return true
+end
+
+function recording_utils.isActive(ifname)
+   local check_cmd = "systemctl is-active n2disk@"..ifname
+   local is_active = executeWithOuput(check_cmd)
+   return ternary(string.match(is_active, "^active"), true, false)
+end
+
+function recording_utils.start(ifname)
+   os.execute("systemctl enable n2disk@"..ifname)
+   os.execute("systemctl restart n2disk@"..ifname)
+end
+
+function recording_utils.stop(ifname)
+   os.execute("systemctl stop n2disk@"..ifname)
+   os.execute("systemctl disable n2disk@"..ifname)
+end
+
+-- #################################
+
+return recording_utils
+