Synnefo » snf-ganeti » ganeti-local

{-| Unittest helpers for ganeti-htools.

-}

{-

Copyright (C) 2009, 2010, 2011, 2012 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 Test.Ganeti.TestCommon where

import Control.Applicative

import Control.Exception (catchJust)

import Control.Monad

import Data.List

import qualified Test.HUnit as HUnit

import Test.QuickCheck

import qualified Text.JSON as J

import System.Environment (getEnv)

import System.Exit (ExitCode(..))

import System.IO.Error (isDoesNotExistError)

import System.Process (readProcessWithExitCode)

-- * Constants

-- | Maximum memory (1TiB, somewhat random value).

maxMem :: Int

maxMem = 1024 * 1024

-- | Maximum disk (8TiB, somewhat random value).

maxDsk :: Int

maxDsk = 1024 * 1024 * 8

-- | Max CPUs (1024, somewhat random value).

maxCpu :: Int

maxCpu = 1024

-- | Max vcpu ratio (random value).

maxVcpuRatio :: Double

maxVcpuRatio = 1024.0

-- | Max spindle ratio (random value).

maxSpindleRatio :: Double

maxSpindleRatio = 1024.0

-- | Max nodes, used just to limit arbitrary instances for smaller

-- opcode definitions (e.g. list of nodes in OpTestDelay).

maxNodes :: Int

maxNodes = 32

-- | Max opcodes or jobs in a submit job and submit many jobs.

maxOpCodes :: Int

maxOpCodes = 16

-- * Helper functions

-- | Checks for equality with proper annotation.

(==?) :: (Show a, Eq a) => a -> a -> Property

(==?) x y = printTestCase

            ("Expected equality, but '" ++

             show x ++ "' /= '" ++ show y ++ "'") (x == y)

infix 3 ==?

-- | Show a message and fail the test.

failTest :: String -> Property

failTest msg = printTestCase msg False

-- | Return the python binary to use. If the PYTHON environment

-- variable is defined, use its value, otherwise use just \"python\".

pythonCmd :: IO String

pythonCmd = catchJust (guard . isDoesNotExistError)

            (getEnv "PYTHON") (const (return "python"))

-- | Run Python with an expression, returning the exit code, standard

-- output and error.

runPython :: String -> String -> IO (ExitCode, String, String)

runPython expr stdin = do

  py_binary <- pythonCmd

  readProcessWithExitCode py_binary ["-c", expr] stdin

-- | Check python exit code, and fail via HUnit assertions if

-- non-zero. Otherwise, return the standard output.

checkPythonResult :: (ExitCode, String, String) -> IO String

checkPythonResult (py_code, py_stdout, py_stderr) = do

  HUnit.assertEqual ("python exited with error: " ++ py_stderr)

       ExitSuccess py_code

  return py_stdout

-- * Arbitrary instances

-- | Defines a DNS name.

newtype DNSChar = DNSChar { dnsGetChar::Char }

instance Arbitrary DNSChar where

  arbitrary = do

    x <- elements (['a'..'z'] ++ ['0'..'9'] ++ "_-")

    return (DNSChar x)

instance Show DNSChar where

  show = show . dnsGetChar

-- | Generates a single name component.

getName :: Gen String

getName = do

  n <- choose (1, 64)

  dn <- vector n

  return (map dnsGetChar dn)

-- | Generates an entire FQDN.

getFQDN :: Gen String

getFQDN = do

  ncomps <- choose (1, 4)

  names <- vectorOf ncomps getName

  return $ intercalate "." names

-- | Combinator that generates a 'Maybe' using a sub-combinator.

getMaybe :: Gen a -> Gen (Maybe a)

getMaybe subgen = do

  bool <- arbitrary

  if bool

    then Just <$> subgen

    else return Nothing

-- | Defines a tag type.

newtype TagChar = TagChar { tagGetChar :: Char }

-- | All valid tag chars. This doesn't need to match _exactly_

-- Ganeti's own tag regex, just enough for it to be close.

tagChar :: [Char]

tagChar = ['a'..'z'] ++ ['A'..'Z'] ++ ['0'..'9'] ++ ".+*/:@-"

instance Arbitrary TagChar where

  arbitrary = do

    c <- elements tagChar

    return (TagChar c)

-- | Generates a tag

genTag :: Gen [TagChar]

genTag = do

  -- the correct value would be C.maxTagLen, but that's way too

  -- verbose in unittests, and at the moment I don't see any possible

  -- bugs with longer tags and the way we use tags in htools

  n <- choose (1, 10)

  vector n

-- | Generates a list of tags (correctly upper bounded).

genTags :: Gen [String]

genTags = do

  -- the correct value would be C.maxTagsPerObj, but per the comment

  -- in genTag, we don't use tags enough in htools to warrant testing

  -- such big values

  n <- choose (0, 10::Int)

  tags <- mapM (const genTag) [1..n]

  return $ map (map tagGetChar) tags

-- | Generates a fields list. This uses the same character set as a

-- DNS name (just for simplicity).

getFields :: Gen [String]

getFields = do

  n <- choose (1, 32)

  vectorOf n getName

-- | Generates a list of a given size with non-duplicate elements.

genUniquesList :: (Eq a, Arbitrary a) => Int -> Gen [a]

genUniquesList cnt =

  foldM (\lst _ -> do

           newelem <- arbitrary `suchThat` (`notElem` lst)

           return (newelem:lst)) [] [1..cnt]

newtype SmallRatio = SmallRatio Double deriving Show

instance Arbitrary SmallRatio where

  arbitrary = do

    v <- choose (0, 1)

    return $ SmallRatio v

-- | Checks for serialisation idempotence.

testSerialisation :: (Eq a, Show a, J.JSON a) => a -> Property

testSerialisation a =

  case J.readJSON (J.showJSON a) of

    J.Error msg -> failTest $ "Failed to deserialise: " ++ msg

    J.Ok a' -> a ==? a'