packages/utils/prometheus-node-exporter-lua/files/usr/bin/prometheus-node-exporter-lua

#!/usr/bin/lua

-- Metrics web server

-- Copyright (c) 2016 Jeff Schornick <jeff@schornick.org>
-- Copyright (c) 2015 Kevin Lyda
-- Licensed under the Apache License, Version 2.0

socket = require("socket")

-- Allow us to call unpack under both lua5.1 and lua5.2+
local unpack = unpack or table.unpack

-- This table defines the scrapers to run.
-- Each corresponds directly to a scraper_<name> function.
scrapers = { "cpu", "load_averages", "memory", "file_handles", "network",
             "network_devices", "time", "uname", "nat", "wifi"}

-- Parsing

function space_split(s)
  elements = {}
  for element in s:gmatch("%S+") do
    table.insert(elements, element)
  end
  return elements
end

function line_split(s)
  elements = {}
  for element in s:gmatch("[^\n]+") do
    table.insert(elements, element)
  end
  return elements
end

function get_contents(filename)
  local f = io.open(filename, "rb")
  local contents = ""
  if f then
    contents = f:read "*a"
    f:close()
  end

  return contents
end

-- Metric printing

function print_metric(metric, labels, value)
  local label_string = ""
  if labels then
    for label,value in pairs(labels) do
      label_string =  label_string .. label .. '="' .. value .. '",'
    end
    label_string = "{" .. string.sub(label_string, 1, -2) .. "}"
  end
  output(string.format("%s%s %s", metric, label_string, value))
end

function metric(name, mtype, labels, value)
  output("# TYPE " .. name .. " " .. mtype)
  local outputter = function(labels, value)
    print_metric(name, labels, value)
  end
  if value then
    outputter(labels, value)
  end
  return outputter
end

local ubus = require "ubus"
local iwinfo = require "iwinfo"

function scraper_wifi()
  local metric_wifi_network_quality = metric("wifi_network_quality","gauge")
  local metric_wifi_network_bitrate = metric("wifi_network_bitrate","gauge")
  local metric_wifi_network_noise = metric("wifi_network_noise","gauge")
  local metric_wifi_network_signal = metric("wifi_network_signal","gauge")

  local metric_wifi_station_signal = metric("wifi_station_signal","gauge")
  local metric_wifi_station_tx_packets = metric("wifi_station_tx_packets","gauge")
  local metric_wifi_station_rx_packets = metric("wifi_station_rx_packets","gauge")

  local u = ubus.connect()
  local status = u:call("network.wireless", "status", {})

  for dev, dev_table in pairs(status) do
    for _, intf in ipairs(dev_table['interfaces']) do
      local ifname = intf['ifname']
      local iw = iwinfo[iwinfo.type(ifname)]
      local labels = {
        channel = iw.channel(ifname),
        ssid = iw.ssid(ifname),
        bssid = iw.bssid(ifname),
        mode = iw.mode(ifname),
        ifname = ifname,
        country = iw.country(ifname),
        frequency = iw.frequency(ifname),
        device = dev,
      }

      local qc = iw.quality(ifname) or 0
      local qm = iw.quality_max(ifname) or 0
      local quality = 0
      if qc > 0 and qm > 0 then
        quality = math.floor((100 / qm) * qc)
      end

      metric_wifi_network_quality(labels, quality)
      metric_wifi_network_noise(labels, iw.noise(ifname) or 0)
      metric_wifi_network_bitrate(labels, iw.bitrate(ifname) or 0)
      metric_wifi_network_signal(labels, iw.signal(ifname) or -255)

      local assoclist = iw.assoclist(ifname)
      for mac, station in pairs(assoclist) do
        local labels = {
          ifname = ifname,
          mac = mac,
        }
        metric_wifi_station_signal(labels, station.signal)
        metric_wifi_station_tx_packets(labels, station.tx_packets)
        metric_wifi_station_rx_packets(labels, station.rx_packets)
      end
    end
  end
end

function scraper_cpu()
  local stat = get_contents("/proc/stat")

  -- system boot time, seconds since epoch
  metric("node_boot_time", "gauge", nil, string.match(stat, "btime ([0-9]+)"))

  -- context switches since boot (all CPUs)
  metric("node_context_switches", "counter", nil, string.match(stat, "ctxt ([0-9]+)"))

  -- cpu times, per CPU, per mode
  local cpu_mode = {"user", "nice", "system", "idle", "iowait", "irq",
                    "softirq", "steal", "guest", "guest_nice"}
  local i = 0
  local cpu_metric = metric("node_cpu", "counter")
  while string.match(stat, string.format("cpu%d ", i)) do
    local cpu = space_split(string.match(stat, string.format("cpu%d ([0-9 ]+)", i)))
    local labels = {cpu = "cpu" .. i}
    for ii, mode in ipairs(cpu_mode) do
      labels['mode'] = mode
      cpu_metric(labels, cpu[ii] / 100)
    end
    i = i + 1
  end

  -- interrupts served
  metric("node_intr", "counter", nil, string.match(stat, "intr ([0-9]+)"))

  -- processes forked
  metric("node_forks", "counter", nil, string.match(stat, "processes ([0-9]+)"))

  -- processes running
  metric("node_procs_running", "gauge", nil, string.match(stat, "procs_running ([0-9]+)"))

  -- processes blocked for I/O
  metric("node_procs_blocked", "gauge", nil, string.match(stat, "procs_blocked ([0-9]+)"))
end

function scraper_load_averages()
  local loadavg = space_split(get_contents("/proc/loadavg"))

  metric("node_load1", "gauge", nil, loadavg[1])
  metric("node_load5", "gauge", nil, loadavg[2])
  metric("node_load15", "gauge", nil, loadavg[3])
end

function scraper_memory()
  local meminfo = line_split(get_contents("/proc/meminfo"):gsub("[):]", ""):gsub("[(]", "_"))

  for i, mi in ipairs(meminfo) do
    local name, size, unit = unpack(space_split(mi))
    if unit == 'kB' then
      size = size * 1024
    end
    metric("node_memory_" .. name, "gauge", nil, size)
  end
end

function scraper_file_handles()
  local file_nr = space_split(get_contents("/proc/sys/fs/file-nr"))

  metric("node_filefd_allocated", "gauge", nil, file_nr[1])
  metric("node_filefd_maximum", "gauge", nil, file_nr[3])
end

function scraper_network()
  -- NOTE: Both of these are missing in OpenWRT kernels.
  --       See: https://dev.openwrt.org/ticket/15781
  local netstat = get_contents("/proc/net/netstat") .. get_contents("/proc/net/snmp")

  -- all devices
  local netsubstat = {"IcmpMsg", "Icmp", "IpExt", "Ip", "TcpExt", "Tcp", "UdpLite", "Udp"}
  for i, nss in ipairs(netsubstat) do
    local substat_s = string.match(netstat, nss .. ": ([A-Z][A-Za-z0-9 ]+)")
    if substat_s then
      local substat = space_split(substat_s)
      local substatv = space_split(string.match(netstat, nss .. ": ([0-9 -]+)"))
      for ii, ss in ipairs(substat) do
        metric("node_netstat_" .. nss .. "_" .. ss, "gauge", nil, substatv[ii])
      end
    end
  end
end

function scraper_network_devices()
  local netdevstat = line_split(get_contents("/proc/net/dev"))
  local netdevsubstat = {"receive_bytes", "receive_packets", "receive_errs",
                   "receive_drop", "receive_fifo", "receive_frame", "receive_compressed",
                   "receive_multicast", "transmit_bytes", "transmit_packets",
                   "transmit_errs", "transmit_drop", "transmit_fifo", "transmit_colls",
                   "transmit_carrier", "transmit_compressed"}
  for i, line in ipairs(netdevstat) do
    netdevstat[i] = string.match(netdevstat[i], "%S.*")
  end
  local nds_table = {}
  local devs = {}
  for i, nds in ipairs(netdevstat) do
    local dev, stat_s = string.match(netdevstat[i], "([^:]+): (.*)")
    if dev then
      nds_table[dev] = space_split(stat_s)
      table.insert(devs, dev)
    end
  end
  for i, ndss in ipairs(netdevsubstat) do
    netdev_metric = metric("node_network_" .. ndss, "gauge")
    for ii, d in ipairs(devs) do
      netdev_metric({device=d}, nds_table[d][i])
    end
  end
end

function scraper_time()
  -- current time
  metric("node_time", "counter", nil, os.time())
end

uname_labels = {
domainname = "",
nodename = "",
release = string.sub(get_contents("/proc/sys/kernel/osrelease"), 1, -2),
sysname = string.sub(get_contents("/proc/sys/kernel/ostype"), 1, -2),
version = string.sub(get_contents("/proc/sys/kernel/version"), 1, -2),
machine = string.sub(io.popen("uname -m"):read("*a"), 1, -2)
}

function scraper_uname()
  uname_labels["domainname"] = string.sub(get_contents("/proc/sys/kernel/domainname"), 1, -2)
  uname_labels["nodename"] = string.sub(get_contents("/proc/sys/kernel/hostname"), 1, -2)
  metric("node_uname_info", "gauge", uname_labels, 1)
end

function scraper_nat()
  -- documetation about nf_conntrack:
  -- https://www.frozentux.net/iptables-tutorial/chunkyhtml/x1309.html
  local natstat = line_split(get_contents("/proc/net/nf_conntrack"))

  nat_metric =  metric("node_nat_traffic", "gauge" )
  for i, e in ipairs(natstat) do
    -- output(string.format("%s\n",e  ))
    local fields = space_split(e)
    local src, dest, bytes;
    bytes = 0;
    for ii, field in ipairs(fields) do
      if src == nil and string.match(field, '^src') then
        src = string.match(field,"src=([^ ]+)");
      elseif dest == nil and string.match(field, '^dst') then
        dest = string.match(field,"dst=([^ ]+)");
      elseif string.match(field, '^bytes') then
        local b = string.match(field, "bytes=([^ ]+)");
        bytes = bytes + b;
        -- output(string.format("\t%d %s",ii,field  ));
      end

    end
    -- local src, dest, bytes = string.match(natstat[i], "src=([^ ]+) dst=([^ ]+) .- bytes=([^ ]+)");
    -- local src, dest, bytes = string.match(natstat[i], "src=([^ ]+) dst=([^ ]+) sport=[^ ]+ dport=[^ ]+ packets=[^ ]+ bytes=([^ ]+)")

    local labels = { src = src, dest = dest }
    -- output(string.format("src=|%s| dest=|%s| bytes=|%s|", src, dest, bytes  ))
    nat_metric(labels, bytes )
  end
end

function timed_scrape(scraper)
  local start_time = socket.gettime()
  -- build the function name and call it from global variable table
  _G["scraper_"..scraper]()
  local duration = socket.gettime() - start_time
  return duration
end

function run_all_scrapers()
  times = {}
  for i,scraper in ipairs(scrapers) do
    runtime = timed_scrape(scraper)
    times[scraper] = runtime
    scrape_time_sums[scraper] = scrape_time_sums[scraper] + runtime
    scrape_counts[scraper] = scrape_counts[scraper] + 1
  end

  local name = "node_exporter_scrape_duration_seconds"
  local duration_metric = metric(name, "summary")
  for i,scraper in ipairs(scrapers) do
    local labels = {collector=scraper, result="success"}
    duration_metric(labels, times[scraper])
    print_metric(name.."_sum", labels, scrape_time_sums[scraper])
    print_metric(name.."_count", labels, scrape_counts[scraper])
  end
end

-- Web server-specific functions

function http_ok_header()
  output("HTTP/1.0 200 OK\r\nServer: lua-metrics\r\nContent-Type: text/plain; version=0.0.4\r\n\r")
end

function http_not_found()
  output("HTTP/1.0 404 Not Found\r\nServer: lua-metrics\r\nContent-Type: text/plain\r\n\r\nERROR: File Not Found.")
end

function serve(request)
  if not string.match(request, "GET /metrics.*") then
    http_not_found()
  else
    http_ok_header()
    run_all_scrapers()
  end
  client:close()
  return true
end

-- Main program

for k,v in ipairs(arg) do
  if (v == "-p") or (v == "--port") then
    port = arg[k+1]
  end
  if (v == "-b") or (v == "--bind") then
    bind = arg[k+1]
  end
end

scrape_counts = {}
scrape_time_sums = {}
for i,scraper in ipairs(scrapers) do
  scrape_counts[scraper] = 0
  scrape_time_sums[scraper] = 0
end

if port then
  server = assert(socket.bind(bind, port))

  while 1 do
    client = server:accept()
    client:settimeout(60)
    local request, err = client:receive()

    if not err then
      output = function (str) client:send(str.."\n") end
      if not serve(request) then
        break
      end
    end
  end
else
  output = print
  run_all_scrapers()
end