Synnefo » snf-ganeti » ganeti-local

{-| Solver for N+1 cluster errors

-}

module Main (main) where

import Data.List

import Data.Function

import Data.Maybe (isJust, fromJust)

import Monad

import System

import System.IO

import System.Console.GetOpt

import qualified System

import Text.Printf (printf)

import qualified Ganeti.HTools.Container as Container

import qualified Ganeti.HTools.Cluster as Cluster

import qualified Ganeti.HTools.Node as Node

import qualified Ganeti.HTools.Instance as Instance

import qualified Ganeti.HTools.CLI as CLI

import Ganeti.HTools.IAlloc

import Ganeti.HTools.Types

-- | Command line options structure.

data Options = Options

    { optShowVer   :: Bool           -- ^ Just show the program version

    , optShowHelp  :: Bool           -- ^ Just show the help

    } deriving Show

-- | Default values for the command line options.

defaultOptions :: Options

defaultOptions  = Options

 { optShowVer   = False

 , optShowHelp  = False

 }

instance CLI.CLIOptions Options where

    showVersion = optShowVer

    showHelp    = optShowHelp

-- | Options list and functions

options :: [OptDescr (Options -> Options)]

options =

    [ Option ['V']     ["version"]

      (NoArg (\ opts -> opts { optShowVer = True}))

      "show the version of the program"

    , Option ['h']     ["help"]

      (NoArg (\ opts -> opts { optShowHelp = True}))

      "show help"

    ]

-- | Compute online nodes from a Node.List

getOnline :: Node.List -> [Node.Node]

getOnline = filter (not . Node.offline) . Container.elems

-- | Try to allocate an instance on the cluster

tryAlloc :: (Monad m) =>

            Node.List

         -> Instance.List

         -> Instance.Instance

         -> Int

         -> m [(Maybe Node.List, [Node.Node])]

tryAlloc nl _ inst 2 =

    let all_nodes = getOnline nl

        all_pairs = liftM2 (,) all_nodes all_nodes

        ok_pairs = filter (\(x, y) -> Node.idx x /= Node.idx y) all_pairs

        sols = map (\(p, s) ->

                        (fst $ Cluster.allocateOnPair nl inst p s, [p, s]))

               ok_pairs

    in return sols

tryAlloc nl _ inst 1 =

    let all_nodes = getOnline nl

        sols = map (\p -> (fst $ Cluster.allocateOnSingle nl inst p, [p]))

               all_nodes

    in return sols

tryAlloc _ _ _ reqn = fail $ "Unsupported number of alllocation \

                             \destinations required (" ++ (show reqn) ++

                                               "), only two supported"

-- | Try to allocate an instance on the cluster

tryReloc :: (Monad m) =>

            Node.List

         -> Instance.List

         -> Idx

         -> Int

         -> [Ndx]

         -> m [(Maybe Node.List, [Node.Node])]

tryReloc nl il xid 1 ex_idx =

    let all_nodes = getOnline nl

        inst = Container.find xid il

        ex_idx' = (Instance.pnode inst):ex_idx

        valid_nodes = filter (not . flip elem ex_idx' . Node.idx) all_nodes

        valid_idxes = map Node.idx valid_nodes

        sols1 = map (\x -> let (mnl, _, _, _) =

                                    Cluster.applyMove nl inst

                                               (Cluster.ReplaceSecondary x)

                            in (mnl, [Container.find x nl])

                     ) valid_idxes

    in return sols1

tryReloc _ _ _ reqn _  = fail $ "Unsupported number of relocation \

                                \destinations required (" ++ (show reqn) ++

                                                  "), only one supported"

filterFails :: (Monad m) => [(Maybe Node.List, [Node.Node])]

            -> m [(Node.List, [Node.Node])]

filterFails sols =

    if null sols then fail "No nodes onto which to allocate at all"

    else let sols' = filter (isJust . fst) sols

         in if null sols' then

                fail "No valid allocation solutions"

            else

                return $ map (\(x, y) -> (fromJust x, y)) sols'

processResults :: (Monad m) => [(Node.List, [Node.Node])]

               -> m (String, [Node.Node])

processResults sols =

    let sols' = map (\(nl', ns) -> (Cluster.compCV  nl', ns)) sols

        sols'' = sortBy (compare `on` fst) sols'

        (best, w) = head sols''

        (worst, l) = last sols''

        info = printf "Valid results: %d, best score: %.8f for node(s) %s, \

                      \worst score: %.8f for node(s) %s" (length sols'')

                      best (intercalate "/" . map Node.name $ w)

                      worst (intercalate "/" . map Node.name $ l)

    in return (info, w)

-- | Main function.

main :: IO ()

main = do

  cmd_args <- System.getArgs

  (_, args) <- CLI.parseOpts cmd_args "hail" options defaultOptions

  when (null args) $ do

         hPutStrLn stderr "Error: this program needs an input file."

         exitWith $ ExitFailure 1

  let input_file = head args

  input_data <- readFile input_file

  request <- case (parseData input_data) of

               Bad err -> do

                 putStrLn $ "Error: " ++ err

                 exitWith $ ExitFailure 1

               Ok rq -> return rq

  let Request rqtype nl il csf = request

      new_nodes = case rqtype of

                    Allocate xi reqn -> tryAlloc nl il xi reqn

                    Relocate idx reqn exnodes ->

                        tryReloc nl il idx reqn exnodes

  let sols = new_nodes >>= filterFails >>= processResults

  let (ok, info, rn) = case sols of

               Ok (info, sn) -> (True, "Request successful: " ++ info,

                                     map ((++ csf) . Node.name) sn)

               Bad s -> (False, "Request failed: " ++ s, [])

      resp = formatResponse ok info rn

  putStrLn resp