init.lua

-- Copyright 2015 Boundary, Inc.
--
-- Licensed under the Apache License, Version 2.0 (the "License");
-- you may not use this file except in compliance with the License.
-- You may obtain a copy of the License at
--
--    http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.

local framework = require('framework')
local Plugin = framework.Plugin
local MeterDataSource = framework.MeterDataSource
local urldecode = framework.string.urldecode
local ipack = framework.util.ipack
local trim = framework.string.trim

local params = framework.params
params.items = params.items or {}

local metric_mapping = {
  ['system.disk.reads.total'] = 'DISK_READS_TOTAL',
  ['system.disk.reads'] = 'DISK_READS',
  ['system.disk.read_bytes.total'] = 'DISK_READ_BYTES_TOTAL',
  ['system.disk.read_bytes'] = 'DISK_READ_BYTES',
  ['system.disk.writes.total'] = 'DISK_WRITES_TOTAL',
  ['system.disk.writes'] = 'DISK_WRITES',
  ['system.disk.write_bytes.total'] = 'DISK_WRITE_BYTES_TOTAL',
  ['system.disk.write_bytes'] = 'DISK_WRITE_BYTES',
  ['system.disk.ios'] = 'DISK_IOS',
  ['system.fs.use_percent'] = 'DISKUSE_SUMMARY',
  ['system.fs.use_percent.total'] = 'DISKUSE_SUMMARY'
}

local ds = MeterDataSource:new()
function ds:onFetch(socket)
  socket:write(self:queryMetricCommand({match = "(system.disk.*|system.fs.use_percent)"}))
end

local function matchItem(item, dir, dev)
  item.dir = item.dir and string.lower(trim(item.dir))
  item.device = item.device and string.lower(trim(item.device))
  dir = dir and string.lower(trim(dir))
  dev = dev and string.lower(trim(dev))
  return (item.dir == dir and item.device == dev) or (item.dir and (not item.device or item.device == "") and item.dir == dir) or ((not item.dir or item.dir == "") and item.device and item.device == dev)
end

local plugin = Plugin:new(params, ds)
function plugin:onParseValues(data)
  local result = {}
  for _, v in ipairs(data) do
    local metric, rest  = string.match(v.metric, '([^|]+)|?(.*)')
    local boundary_metric = metric_mapping[metric]  
    if boundary_metric then
      if string.find(metric, 'total') then
        result[boundary_metric] = { value = v.value, timestamp = v.timestamp }
      elseif rest then
        local dir, dev = string.match(rest, '^dir=(.+)&dev=(.+)')
        dir = urldecode(dir)
        dev = urldecode(dev)
        for _, item in ipairs(params.items) do
          if matchItem(item, dir, dev) then
            local source = self.source .. '.' .. (item.diskname or dir .. '.' .. dev) 
            ipack(result, boundary_metric, v.value, v.timestamp, source)
            break
          end
        end
      end
    end
  end
  return result
end

plugin:run()