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{-# LANGUAGE TemplateHaskell #-} |
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|
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{-| Implementation of the Ganeti LUXI interface. |
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|
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-} |
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|
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{- |
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|
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Copyright (C) 2009, 2010, 2011, 2012 Google Inc. |
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|
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This program is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2 of the License, or |
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(at your option) any later version. |
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|
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This program is distributed in the hope that it will be useful, but |
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WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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General Public License for more details. |
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|
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You should have received a copy of the GNU General Public License |
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along with this program; if not, write to the Free Software |
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
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02110-1301, USA. |
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|
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-} |
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|
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module Ganeti.Luxi |
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( LuxiOp(..) |
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, LuxiReq(..) |
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, Client |
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, JobId |
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, RecvResult(..) |
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, strOfOp |
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, getClient |
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, getServer |
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, acceptClient |
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, closeClient |
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, closeServer |
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, callMethod |
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, submitManyJobs |
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, queryJobsStatus |
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, buildCall |
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, buildResponse |
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, validateCall |
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, decodeCall |
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, recvMsg |
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, recvMsgExt |
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, sendMsg |
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, allLuxiCalls |
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) where |
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|
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import Control.Exception (catch) |
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import Data.IORef |
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import Data.Ratio (numerator, denominator) |
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import qualified Data.ByteString as B |
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import qualified Data.ByteString.UTF8 as UTF8 |
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import Data.Word (Word8) |
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import Control.Monad |
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import Text.JSON (encodeStrict, decodeStrict) |
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import qualified Text.JSON as J |
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import Text.JSON.Pretty (pp_value) |
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import Text.JSON.Types |
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import System.Directory (removeFile) |
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import System.IO (hClose, hFlush, hWaitForInput, Handle, IOMode(..)) |
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import System.IO.Error (isEOFError) |
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import System.Timeout |
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import qualified Network.Socket as S |
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|
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import Ganeti.BasicTypes |
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import Ganeti.Constants |
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import Ganeti.Errors |
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import Ganeti.JSON |
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import Ganeti.Jobs (JobStatus) |
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import Ganeti.OpCodes |
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import Ganeti.Utils |
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import qualified Ganeti.Query.Language as Qlang |
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import Ganeti.THH |
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|
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-- * Utility functions |
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|
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-- | Wrapper over System.Timeout.timeout that fails in the IO monad. |
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withTimeout :: Int -> String -> IO a -> IO a |
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withTimeout secs descr action = do |
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result <- timeout (secs * 1000000) action |
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case result of |
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Nothing -> fail $ "Timeout in " ++ descr |
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Just v -> return v |
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|
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-- * Generic protocol functionality |
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|
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-- | Result of receiving a message from the socket. |
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data RecvResult = RecvConnClosed -- ^ Connection closed |
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| RecvError String -- ^ Any other error |
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| RecvOk String -- ^ Successfull receive |
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deriving (Show, Read, Eq) |
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|
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-- | The Ganeti job type. |
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type JobId = Int |
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|
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-- | Currently supported Luxi operations and JSON serialization. |
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$(genLuxiOp "LuxiOp" |
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[ (luxiReqQuery, |
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[ simpleField "what" [t| Qlang.ItemType |] |
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, simpleField "fields" [t| [String] |] |
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, simpleField "qfilter" [t| Qlang.Filter Qlang.FilterField |] |
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]) |
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, (luxiReqQueryFields, |
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[ simpleField "what" [t| Qlang.ItemType |] |
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, simpleField "fields" [t| [String] |] |
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]) |
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, (luxiReqQueryNodes, |
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[ simpleField "names" [t| [String] |] |
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, simpleField "fields" [t| [String] |] |
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, simpleField "lock" [t| Bool |] |
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]) |
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, (luxiReqQueryGroups, |
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[ simpleField "names" [t| [String] |] |
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, simpleField "fields" [t| [String] |] |
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, simpleField "lock" [t| Bool |] |
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]) |
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, (luxiReqQueryInstances, |
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[ simpleField "names" [t| [String] |] |
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, simpleField "fields" [t| [String] |] |
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, simpleField "lock" [t| Bool |] |
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]) |
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, (luxiReqQueryJobs, |
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[ simpleField "ids" [t| [Int] |] |
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, simpleField "fields" [t| [String] |] |
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]) |
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, (luxiReqQueryExports, |
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[ simpleField "nodes" [t| [String] |] |
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, simpleField "lock" [t| Bool |] |
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]) |
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, (luxiReqQueryConfigValues, |
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[ simpleField "fields" [t| [String] |] ] |
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) |
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, (luxiReqQueryClusterInfo, []) |
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, (luxiReqQueryTags, |
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[ customField 'decodeTagObject 'encodeTagObject $ |
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simpleField "kind" [t| TagObject |] |
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]) |
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, (luxiReqSubmitJob, |
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[ simpleField "job" [t| [OpCode] |] ] |
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) |
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, (luxiReqSubmitManyJobs, |
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[ simpleField "ops" [t| [[OpCode]] |] ] |
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) |
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, (luxiReqWaitForJobChange, |
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[ simpleField "job" [t| Int |] |
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, simpleField "fields" [t| [String]|] |
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, simpleField "prev_job" [t| JSValue |] |
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, simpleField "prev_log" [t| JSValue |] |
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, simpleField "tmout" [t| Int |] |
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]) |
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, (luxiReqArchiveJob, |
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[ simpleField "job" [t| Int |] ] |
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) |
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, (luxiReqAutoArchiveJobs, |
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[ simpleField "age" [t| Int |] |
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, simpleField "tmout" [t| Int |] |
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]) |
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, (luxiReqCancelJob, |
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[ simpleField "job" [t| Int |] ] |
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) |
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, (luxiReqChangeJobPriority, |
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[ simpleField "job" [t| Int |] |
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, simpleField "priority" [t| Int |] ] |
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) |
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, (luxiReqSetDrainFlag, |
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[ simpleField "flag" [t| Bool |] ] |
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) |
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, (luxiReqSetWatcherPause, |
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[ simpleField "duration" [t| Double |] ] |
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) |
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]) |
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|
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$(makeJSONInstance ''LuxiReq) |
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-- | List of all defined Luxi calls. |
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$(genAllConstr (drop 3) ''LuxiReq "allLuxiCalls") |
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|
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-- | The serialisation of LuxiOps into strings in messages. |
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$(genStrOfOp ''LuxiOp "strOfOp") |
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|
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-- | Type holding the initial (unparsed) Luxi call. |
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data LuxiCall = LuxiCall LuxiReq JSValue |
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|
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-- | The end-of-message separator. |
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eOM :: Word8 |
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eOM = 3 |
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|
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-- | The end-of-message encoded as a ByteString. |
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bEOM :: B.ByteString |
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bEOM = B.singleton eOM |
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|
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-- | Valid keys in the requests and responses. |
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data MsgKeys = Method |
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| Args |
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| Success |
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| Result |
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|
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-- | The serialisation of MsgKeys into strings in messages. |
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$(genStrOfKey ''MsgKeys "strOfKey") |
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|
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-- | Luxi client encapsulation. |
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data Client = Client { socket :: Handle -- ^ The socket of the client |
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, rbuf :: IORef B.ByteString -- ^ Already received buffer |
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} |
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|
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-- | Connects to the master daemon and returns a luxi Client. |
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getClient :: String -> IO Client |
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getClient path = do |
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s <- S.socket S.AF_UNIX S.Stream S.defaultProtocol |
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withTimeout luxiDefCtmo "creating luxi connection" $ |
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S.connect s (S.SockAddrUnix path) |
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rf <- newIORef B.empty |
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h <- S.socketToHandle s ReadWriteMode |
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return Client { socket=h, rbuf=rf } |
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|
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-- | Creates and returns a server endpoint. |
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getServer :: FilePath -> IO S.Socket |
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getServer path = do |
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s <- S.socket S.AF_UNIX S.Stream S.defaultProtocol |
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S.bindSocket s (S.SockAddrUnix path) |
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S.listen s 5 -- 5 is the max backlog |
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return s |
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|
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-- | Closes a server endpoint. |
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-- FIXME: this should be encapsulated into a nicer type. |
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closeServer :: FilePath -> S.Socket -> IO () |
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closeServer path sock = do |
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S.sClose sock |
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removeFile path |
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|
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-- | Accepts a client |
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acceptClient :: S.Socket -> IO Client |
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acceptClient s = do |
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-- second return is the address of the client, which we ignore here |
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(client_socket, _) <- S.accept s |
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new_buffer <- newIORef B.empty |
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handle <- S.socketToHandle client_socket ReadWriteMode |
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return Client { socket=handle, rbuf=new_buffer } |
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|
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-- | Closes the client socket. |
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closeClient :: Client -> IO () |
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closeClient = hClose . socket |
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|
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-- | Sends a message over a luxi transport. |
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sendMsg :: Client -> String -> IO () |
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sendMsg s buf = withTimeout luxiDefRwto "sending luxi message" $ do |
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let encoded = UTF8.fromString buf |
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handle = socket s |
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B.hPut handle encoded |
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B.hPut handle bEOM |
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hFlush handle |
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-- | Given a current buffer and the handle, it will read from the |
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-- network until we get a full message, and it will return that |
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-- message and the leftover buffer contents. |
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recvUpdate :: Handle -> B.ByteString -> IO (B.ByteString, B.ByteString) |
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recvUpdate handle obuf = do |
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nbuf <- withTimeout luxiDefRwto "reading luxi response" $ do |
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_ <- hWaitForInput handle (-1) |
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B.hGetNonBlocking handle 4096 |
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let (msg, remaining) = B.break (eOM ==) nbuf |
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newbuf = B.append obuf msg |
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if B.null remaining |
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then recvUpdate handle newbuf |
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else return (newbuf, B.tail remaining) |
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|
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-- | Waits for a message over a luxi transport. |
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recvMsg :: Client -> IO String |
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recvMsg s = do |
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cbuf <- readIORef $ rbuf s |
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let (imsg, ibuf) = B.break (eOM ==) cbuf |
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(msg, nbuf) <- |
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if B.null ibuf -- if old buffer didn't contain a full message |
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then recvUpdate (socket s) cbuf -- then we read from network |
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else return (imsg, B.tail ibuf) -- else we return data from our buffer |
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writeIORef (rbuf s) nbuf |
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return $ UTF8.toString msg |
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|
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-- | Extended wrapper over recvMsg. |
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recvMsgExt :: Client -> IO RecvResult |
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recvMsgExt s = |
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Control.Exception.catch (liftM RecvOk (recvMsg s)) $ \e -> |
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return $ if isEOFError e |
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then RecvConnClosed |
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else RecvError (show e) |
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|
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-- | Serialize a request to String. |
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buildCall :: LuxiOp -- ^ The method |
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-> String -- ^ The serialized form |
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buildCall lo = |
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let ja = [ (strOfKey Method, J.showJSON $ strOfOp lo) |
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, (strOfKey Args, opToArgs lo) |
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] |
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jo = toJSObject ja |
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in encodeStrict jo |
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|
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-- | Serialize the response to String. |
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buildResponse :: Bool -- ^ Success |
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-> JSValue -- ^ The arguments |
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-> String -- ^ The serialized form |
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buildResponse success args = |
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let ja = [ (strOfKey Success, JSBool success) |
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, (strOfKey Result, args)] |
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jo = toJSObject ja |
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in encodeStrict jo |
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|
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-- | Check that luxi request contains the required keys and parse it. |
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validateCall :: String -> Result LuxiCall |
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validateCall s = do |
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arr <- fromJResult "parsing top-level luxi message" $ |
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decodeStrict s::Result (JSObject JSValue) |
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let aobj = fromJSObject arr |
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call <- fromObj aobj (strOfKey Method)::Result LuxiReq |
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args <- fromObj aobj (strOfKey Args) |
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return (LuxiCall call args) |
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|
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-- | Converts Luxi call arguments into a 'LuxiOp' data structure. |
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-- |
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-- This is currently hand-coded until we make it more uniform so that |
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-- it can be generated using TH. |
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decodeCall :: LuxiCall -> Result LuxiOp |
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decodeCall (LuxiCall call args) = |
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case call of |
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ReqQueryJobs -> do |
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(jid, jargs) <- fromJVal args |
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rid <- mapM parseJobId jid |
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let rargs = map fromJSString jargs |
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return $ QueryJobs rid rargs |
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ReqQueryInstances -> do |
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(names, fields, locking) <- fromJVal args |
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return $ QueryInstances names fields locking |
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ReqQueryNodes -> do |
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(names, fields, locking) <- fromJVal args |
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return $ QueryNodes names fields locking |
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ReqQueryGroups -> do |
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(names, fields, locking) <- fromJVal args |
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return $ QueryGroups names fields locking |
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ReqQueryClusterInfo -> |
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return QueryClusterInfo |
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ReqQuery -> do |
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(what, fields, qfilter) <- fromJVal args |
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return $ Query what fields qfilter |
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ReqQueryFields -> do |
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(what, fields) <- fromJVal args |
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fields' <- case fields of |
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JSNull -> return [] |
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_ -> fromJVal fields |
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return $ QueryFields what fields' |
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ReqSubmitJob -> do |
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[ops1] <- fromJVal args |
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ops2 <- mapM (fromJResult (luxiReqToRaw call) . J.readJSON) ops1 |
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return $ SubmitJob ops2 |
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ReqSubmitManyJobs -> do |
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[ops1] <- fromJVal args |
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ops2 <- mapM (fromJResult (luxiReqToRaw call) . J.readJSON) ops1 |
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return $ SubmitManyJobs ops2 |
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ReqWaitForJobChange -> do |
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(jid, fields, pinfo, pidx, wtmout) <- |
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-- No instance for 5-tuple, code copied from the |
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-- json sources and adapted |
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fromJResult "Parsing WaitForJobChange message" $ |
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case args of |
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JSArray [a, b, c, d, e] -> |
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(,,,,) `fmap` |
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J.readJSON a `ap` |
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J.readJSON b `ap` |
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J.readJSON c `ap` |
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J.readJSON d `ap` |
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J.readJSON e |
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_ -> J.Error "Not enough values" |
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rid <- parseJobId jid |
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return $ WaitForJobChange rid fields pinfo pidx wtmout |
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ReqArchiveJob -> do |
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[jid] <- fromJVal args |
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rid <- parseJobId jid |
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return $ ArchiveJob rid |
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ReqAutoArchiveJobs -> do |
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(age, tmout) <- fromJVal args |
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return $ AutoArchiveJobs age tmout |
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ReqQueryExports -> do |
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(nodes, lock) <- fromJVal args |
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return $ QueryExports nodes lock |
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ReqQueryConfigValues -> do |
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[fields] <- fromJVal args |
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return $ QueryConfigValues fields |
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ReqQueryTags -> do |
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(kind, name) <- fromJVal args |
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item <- tagObjectFrom kind name |
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return $ QueryTags item |
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ReqCancelJob -> do |
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[job] <- fromJVal args |
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rid <- parseJobId job |
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return $ CancelJob rid |
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ReqChangeJobPriority -> do |
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(job, priority) <- fromJVal args |
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rid <- parseJobId job |
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return $ ChangeJobPriority rid priority |
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ReqSetDrainFlag -> do |
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[flag] <- fromJVal args |
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return $ SetDrainFlag flag |
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ReqSetWatcherPause -> do |
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[duration] <- fromJVal args |
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return $ SetWatcherPause duration |
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|
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-- | Check that luxi responses contain the required keys and that the |
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-- call was successful. |
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validateResult :: String -> ErrorResult JSValue |
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validateResult s = do |
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when (UTF8.replacement_char `elem` s) $ |
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fail "Failed to decode UTF-8, detected replacement char after decoding" |
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oarr <- fromJResult "Parsing LUXI response" (decodeStrict s) |
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let arr = J.fromJSObject oarr |
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status <- fromObj arr (strOfKey Success) |
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result <- fromObj arr (strOfKey Result) |
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if status |
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then return result |
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else decodeError result |
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|
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-- | Try to decode an error from the server response. This function |
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-- will always fail, since it's called only on the error path (when |
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-- status is False). |
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decodeError :: JSValue -> ErrorResult JSValue |
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decodeError val = |
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case fromJVal val of |
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Ok e -> Bad e |
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Bad msg -> Bad $ GenericError msg |
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|
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-- | Generic luxi method call. |
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callMethod :: LuxiOp -> Client -> IO (ErrorResult JSValue) |
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callMethod method s = do |
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sendMsg s $ buildCall method |
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result <- recvMsg s |
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let rval = validateResult result |
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return rval |
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|
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-- | Parses a job ID. |
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parseJobId :: JSValue -> Result JobId |
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parseJobId (JSString x) = tryRead "parsing job id" . fromJSString $ x |
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parseJobId (JSRational _ x) = |
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if denominator x /= 1 |
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then Bad $ "Got fractional job ID from master daemon?! Value:" ++ show x |
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-- FIXME: potential integer overflow here on 32-bit platforms |
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else Ok . fromIntegral . numerator $ x |
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parseJobId x = Bad $ "Wrong type/value for job id: " ++ show x |
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|
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-- | Parse job submission result. |
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parseSubmitJobResult :: JSValue -> ErrorResult JobId |
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parseSubmitJobResult (JSArray [JSBool True, v]) = |
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case parseJobId v of |
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Bad msg -> Bad $ LuxiError msg |
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Ok v' -> Ok v' |
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parseSubmitJobResult (JSArray [JSBool False, JSString x]) = |
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Bad . LuxiError $ fromJSString x |
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parseSubmitJobResult v = |
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Bad . LuxiError $ "Unknown result from the master daemon: " ++ |
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show (pp_value v) |
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|
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-- | Specialized submitManyJobs call. |
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submitManyJobs :: Client -> [[OpCode]] -> IO (ErrorResult [JobId]) |
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submitManyJobs s jobs = do |
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rval <- callMethod (SubmitManyJobs jobs) s |
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-- map each result (status, payload) pair into a nice Result ADT |
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return $ case rval of |
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Bad x -> Bad x |
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Ok (JSArray r) -> mapM parseSubmitJobResult r |
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x -> Bad . LuxiError $ |
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"Cannot parse response from Ganeti: " ++ show x |
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|
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-- | Custom queryJobs call. |
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queryJobsStatus :: Client -> [JobId] -> IO (ErrorResult [JobStatus]) |
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queryJobsStatus s jids = do |
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rval <- callMethod (QueryJobs jids ["status"]) s |
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return $ case rval of |
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Bad x -> Bad x |
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Ok y -> case J.readJSON y::(J.Result [[JobStatus]]) of |
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J.Ok vals -> if any null vals |
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then Bad $ |
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LuxiError "Missing job status field" |
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else Ok (map head vals) |
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J.Error x -> Bad $ LuxiError x |