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{-| Instance status data collector.

-}

{-

Copyright (C) 2013 Google Inc.

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

02110-1301, USA.

-}

module Ganeti.DataCollectors.InstStatus

  ( main

  , options

  , arguments

  , dcName

  , dcVersion

  , dcFormatVersion

  , dcCategory

  , dcKind

  , dcReport

  ) where

import Control.Exception.Base

import Data.List

import Data.Maybe

import qualified Data.Map as Map

import Network.BSD (getHostName)

import qualified Text.JSON as J

import Ganeti.Confd.ClientFunctions

import Ganeti.Common

import Ganeti.DataCollectors.CLI

import Ganeti.DataCollectors.InstStatusTypes

import Ganeti.DataCollectors.Types

import Ganeti.Hypervisor.Xen

import Ganeti.Hypervisor.Xen.Types

import Ganeti.Logging

import Ganeti.Objects

import Ganeti.Path

import Ganeti.Types

import Ganeti.Utils

-- | The name of this data collector.

dcName :: String

dcName = "inst-status-xen"

-- | The version of this data collector.

dcVersion :: DCVersion

dcVersion = DCVerBuiltin

-- | The version number for the data format of this data collector.

dcFormatVersion :: Int

dcFormatVersion = 1

-- | The category of this data collector.

dcCategory :: Maybe DCCategory

dcCategory = Just DCInstance

-- | The kind of this data collector.

dcKind :: DCKind

dcKind = DCKStatus

-- | The report of this data collector.

dcReport :: IO DCReport

dcReport = buildInstStatusReport Nothing Nothing

-- * Command line options

options :: IO [OptType]

options = return

  [ oConfdAddr

  , oConfdPort

  ]

-- | The list of arguments supported by the program.

arguments :: [ArgCompletion]

arguments = []

-- | Try to get the reason trail for an instance. In case it is not possible,

-- log the failure and return an empty list instead.

getReasonTrail :: String -> IO ReasonTrail

getReasonTrail instanceName = do

  fileName <- getInstReasonFilename instanceName

  content <- try $ readFile fileName

  case content of

    Left e -> do

      logWarning $

        "Unable to open the reason trail for instance " ++ instanceName ++

        " expected at " ++ fileName ++ ": " ++ show (e :: IOException)

      return []

    Right trailString ->

      case J.decode trailString of

        J.Ok t -> return t

        J.Error msg -> do

          logWarning $ "Unable to parse the reason trail: " ++ msg

          return []

-- | Determine the value of the status field for the report of one instance

computeStatusField :: AdminState -> ActualState -> DCStatus

computeStatusField AdminDown actualState =

  if actualState `notElem` [ActualShutdown, ActualDying]

    then DCStatus DCSCBad "The instance is not stopped as it should be"

    else DCStatus DCSCOk ""

computeStatusField AdminUp ActualHung =

  DCStatus DCSCUnknown "Instance marked as running, but it appears to be hung"

computeStatusField AdminUp actualState =

  if actualState `notElem` [ActualRunning, ActualBlocked]

    then DCStatus DCSCBad "The instance is not running as it should be"

    else DCStatus DCSCOk ""

computeStatusField AdminOffline _ =

  -- FIXME: The "offline" status seems not to be used anywhere in the source

  -- code, but it is defined, so we have to consider it anyway here.

  DCStatus DCSCUnknown "The instance is marked as offline"

-- Builds the status of an instance using runtime information about the Xen

-- Domains, their uptime information and the static information provided by

-- the ConfD server.

buildStatus :: Map.Map String Domain -> Map.Map Int UptimeInfo -> Instance

  -> IO InstStatus

buildStatus domains uptimes inst = do

  let name = instName inst

      currDomain = Map.lookup name domains

      idNum = fmap domId currDomain

      currUInfo = idNum >>= (`Map.lookup` uptimes)

      uptime = fmap uInfoUptime currUInfo

      adminState = instAdminState inst

      actualState =

        if adminState == AdminDown && isNothing currDomain

          then ActualShutdown

          else case currDomain of

            (Just dom@(Domain _ _ _ _ (Just isHung))) ->

              if isHung

                then ActualHung

                else domState dom

            _ -> ActualUnknown

      status = computeStatusField adminState actualState

  trail <- getReasonTrail name

  return $

    InstStatus

      name

      (instUuid inst)

      adminState

      actualState

      uptime

      (instMtime inst)

      trail

      status

-- | Compute the status code and message, given the current DRBD data

-- The final state will have the code corresponding to the worst code of

-- all the devices, and the error message given from the concatenation of the

-- non-empty error messages.

computeGlobalStatus :: [InstStatus] -> DCStatus

computeGlobalStatus instStatusList =

  let dcstatuses = map iStatStatus instStatusList

      statuses = map (\s -> (dcStatusCode s, dcStatusMessage s)) dcstatuses

      (code, strList) = foldr mergeStatuses (DCSCOk, [""]) statuses

  in DCStatus code $ intercalate "\n" strList

-- | Build the report of this data collector, containing all the information

-- about the status of the instances.

buildInstStatusReport :: Maybe String -> Maybe Int -> IO DCReport

buildInstStatusReport srvAddr srvPort = do

  node <- getHostName

  answer <- getInstances node srvAddr srvPort

  inst <- exitIfBad "Can't get instance info from ConfD" answer

  domains <- getInferredDomInfo

  uptimes <- getUptimeInfo

  let primaryInst =  fst inst

  iStatus <- mapM (buildStatus domains uptimes) primaryInst

  let globalStatus = computeGlobalStatus iStatus

      jsonReport = J.showJSON $ ReportData iStatus globalStatus

  buildReport dcName dcVersion dcFormatVersion dcCategory dcKind jsonReport

-- | Main function.

main :: Options -> [String] -> IO ()

main opts _ = do

  report <- buildInstStatusReport (optConfdAddr opts) (optConfdPort opts)

  putStrLn $ J.encode report