Synnefo » snf-ganeti

{-| Solver for N+1 cluster errors

-}

module Main (main) where

import Data.List

import Data.Function

import Monad

import System

import System.IO

import System.Console.GetOpt

import qualified System

import Text.Printf (printf)

import qualified Container

import qualified Instance

import qualified Cluster

import Utils

import Rapi

-- | Command line options structure.

data Options = Options

    { optShowNodes   :: Bool

    , optShowCmds    :: Bool

    , optNodef       :: FilePath

    , optInstf       :: FilePath

    , optMinDepth    :: Int

    , optMaxRemovals :: Int

    , optMinDelta    :: Int

    , optMaxDelta    :: Int

    , optMaster    :: String

    } deriving Show

-- | Default values for the command line options.

defaultOptions :: Options

defaultOptions    = Options

 { optShowNodes   = False

 , optShowCmds    = False

 , optNodef       = "nodes"

 , optInstf       = "instances"

 , optMinDepth    = 1

 , optMaxRemovals = -1

 , optMinDelta    = 0

 , optMaxDelta    = -1

 , optMaster    = ""

 }

{- | Start computing the solution at the given depth and recurse until

we find a valid solution or we exceed the maximum depth.

-}

iterateDepth :: Cluster.NodeList

             -> [Instance.Instance]

             -> Int

             -> Int

             -> Int

             -> Int

             -> IO (Maybe Cluster.Solution)

iterateDepth nl bad_instances depth max_removals min_delta max_delta =

    let

        max_depth = length bad_instances

        sol = Cluster.computeSolution nl bad_instances depth

              max_removals min_delta max_delta

    in

      do

        printf "%d " depth

        hFlush stdout

        case sol `seq` sol of

          Nothing ->

              if depth > max_depth then

                  return Nothing

              else

                  iterateDepth nl bad_instances (depth + 1)

                               max_removals min_delta max_delta

          _ -> return sol

-- | Options list and functions

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

options =

    [ Option ['p']     ["print-nodes"]

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

      "print the final node list"

    , Option ['C']     ["print-commands"]

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

      "print the ganeti command list for reaching the solution"

     , Option ['n']     ["nodes"]

      (ReqArg (\ f opts -> opts { optNodef = f }) "FILE")

      "the node list FILE"

     , Option ['i']     ["instances"]

      (ReqArg (\ f opts -> opts { optInstf =  f }) "FILE")

      "the instance list FILE"

     , Option ['d']     ["depth"]

      (ReqArg (\ i opts -> opts { optMinDepth =  (read i)::Int }) "D")

      "start computing the solution at depth D"

     , Option ['r']     ["max-removals"]

      (ReqArg (\ i opts -> opts { optMaxRemovals =  (read i)::Int }) "R")

      "do not process more than R removal sets (useful for high depths)"

     , Option ['L']     ["max-delta"]

      (ReqArg (\ i opts -> opts { optMaxDelta =  (read i)::Int }) "L")

      "refuse solutions with delta higher than L"

     , Option ['l']     ["min-delta"]

      (ReqArg (\ i opts -> opts { optMinDelta =  (read i)::Int }) "L")

      "return once a solution with delta L or lower has been found"

     , Option ['m']     ["master"]

      (ReqArg (\ m opts -> opts { optMaster = m }) "ADDRESS")

      "collect data via RAPI at the given ADDRESS"

     ]

-- | Command line parser, using the 'options' structure.

parseOpts :: [String] -> IO (Options, [String])

parseOpts argv =

    case getOpt Permute options argv of

      (o,n,[]  ) ->

          return (foldl (flip id) defaultOptions o, n)

      (_,_,errs) ->

          ioError (userError (concat errs ++ usageInfo header options))

      where header = "Usage: hn1 [OPTION...]"

-- | Main function.

main :: IO ()

main = do

  cmd_args <- System.getArgs

  (opts, _) <- parseOpts cmd_args

  let min_depth = optMinDepth opts

  let (node_data, inst_data) =

          case optMaster opts of

            "" -> (readFile $ optNodef opts,

                   readFile $ optInstf opts)

            host -> (readData getNodes host,

                     readData getInstances host)

  (nl, il, ktn, kti) <- liftM2 Cluster.loadData node_data inst_data

  printf "Loaded %d nodes, %d instances\n"

             (Container.size nl)

             (Container.size il)

  let (bad_nodes, bad_instances) = Cluster.computeBadItems nl il

  printf "Initial check done: %d bad nodes, %d bad instances.\n"

             (length bad_nodes) (length bad_instances)

  when (null bad_instances) $ do

         putStrLn "Happy time! Cluster is fine, no need to burn CPU."

         exitWith ExitSuccess

  when (length bad_instances < min_depth) $ do

         printf "Error: depth %d is higher than the number of bad instances.\n"

                min_depth

         exitWith $ ExitFailure 2

  putStr "Computing solution: depth "

  hFlush stdout

  result <- iterateDepth nl bad_instances min_depth (optMaxRemovals opts)

            (optMinDelta opts) (optMaxDelta opts)

  let (min_d, solution) =

          case result of

            Just (Cluster.Solution a b) -> (a, b)

            Nothing -> (-1, [])

  when (min_d == -1) $ do

         putStrLn "failed. Try to run with higher depth."

         exitWith $ ExitFailure 1

  printf "found.\nSolution (delta=%d):\n" $! min_d

  let (sol_strs, cmd_strs) = Cluster.printSolution il ktn kti solution

  putStr $ unlines $ sol_strs

  when (optShowCmds opts) $

       do

         putStrLn ""

         putStrLn "Commands to run to reach the above solution:"

         putStr $ unlines $ map ("  echo gnt-instance " ++) $ concat cmd_strs

  when (optShowNodes opts) $

       do

         let (orig_mem, orig_disk) = Cluster.totalResources nl

             ns = Cluster.applySolution nl il solution

             (final_mem, final_disk) = Cluster.totalResources ns

         putStrLn ""

         putStrLn "Final cluster status:"

         putStrLn $ Cluster.printNodes ktn ns

         printf "Original: mem=%d disk=%d\n" orig_mem orig_disk

         printf "Final:    mem=%d disk=%d\n" final_mem final_disk