root / htools / Ganeti / OpCodes.hs @ 519edd9f
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{-| Implementation of the opcodes. |
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-} |
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{- |
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Copyright (C) 2009, 2010, 2011 Google Inc. |
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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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module Ganeti.OpCodes |
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( OpCode(..) |
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, ReplaceDisksMode(..) |
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, opID |
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) where |
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|
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import Control.Monad |
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import Text.JSON (readJSON, showJSON, makeObj, JSON) |
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import qualified Text.JSON as J |
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import Text.JSON.Types |
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import Ganeti.HTools.Utils |
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-- | Replace disks type. |
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data ReplaceDisksMode = ReplaceOnPrimary |
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| ReplaceOnSecondary |
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| ReplaceNewSecondary |
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| ReplaceAuto |
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deriving (Show, Read, Eq) |
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|
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instance JSON ReplaceDisksMode where |
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showJSON m = case m of |
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ReplaceOnPrimary -> showJSON "replace_on_primary" |
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ReplaceOnSecondary -> showJSON "replace_on_secondary" |
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ReplaceNewSecondary -> showJSON "replace_new_secondary" |
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ReplaceAuto -> showJSON "replace_auto" |
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readJSON s = case readJSON s of |
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J.Ok "replace_on_primary" -> J.Ok ReplaceOnPrimary |
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J.Ok "replace_on_secondary" -> J.Ok ReplaceOnSecondary |
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J.Ok "replace_new_secondary" -> J.Ok ReplaceNewSecondary |
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J.Ok "replace_auto" -> J.Ok ReplaceAuto |
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_ -> J.Error "Can't parse a valid ReplaceDisksMode" |
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|
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-- | OpCode representation. |
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-- |
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-- We only implement a subset of Ganeti opcodes, but only what we |
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-- actually use in the htools codebase. |
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data OpCode = OpTestDelay Double Bool [String] |
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| OpInstanceReplaceDisks String (Maybe String) ReplaceDisksMode |
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[Int] (Maybe String) |
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| OpInstanceFailover String Bool |
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| OpInstanceMigrate String Bool Bool Bool |
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deriving (Show, Read, Eq) |
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-- | Computes the OP_ID for an OpCode. |
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opID :: OpCode -> String |
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opID (OpTestDelay _ _ _) = "OP_TEST_DELAY" |
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opID (OpInstanceReplaceDisks _ _ _ _ _) = "OP_INSTANCE_REPLACE_DISKS" |
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opID (OpInstanceFailover _ _) = "OP_INSTANCE_FAILOVER" |
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opID (OpInstanceMigrate _ _ _ _) = "OP_INSTANCE_MIGRATE" |
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|
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-- | Loads an OpCode from the JSON serialised form. |
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loadOpCode :: JSValue -> J.Result OpCode |
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loadOpCode v = do |
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o <- liftM J.fromJSObject (readJSON v) |
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let extract x = fromObj o x |
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op_id <- extract "OP_ID" |
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case op_id of |
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"OP_TEST_DELAY" -> do |
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on_nodes <- extract "on_nodes" |
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on_master <- extract "on_master" |
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duration <- extract "duration" |
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return $ OpTestDelay duration on_master on_nodes |
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"OP_INSTANCE_REPLACE_DISKS" -> do |
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inst <- extract "instance_name" |
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node <- maybeFromObj o "remote_node" |
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mode <- extract "mode" |
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disks <- extract "disks" |
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ialloc <- maybeFromObj o "iallocator" |
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return $ OpInstanceReplaceDisks inst node mode disks ialloc |
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"OP_INSTANCE_FAILOVER" -> do |
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inst <- extract "instance_name" |
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consist <- extract "ignore_consistency" |
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return $ OpInstanceFailover inst consist |
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"OP_INSTANCE_MIGRATE" -> do |
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inst <- extract "instance_name" |
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live <- extract "live" |
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cleanup <- extract "cleanup" |
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allow_failover <- fromObjWithDefault o "allow_failover" False |
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return $ OpInstanceMigrate inst live cleanup allow_failover |
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_ -> J.Error $ "Unknown opcode " ++ op_id |
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|
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-- | Serialises an opcode to JSON. |
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saveOpCode :: OpCode -> JSValue |
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saveOpCode op@(OpTestDelay duration on_master on_nodes) = |
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let ol = [ ("OP_ID", showJSON $ opID op) |
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, ("duration", showJSON duration) |
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, ("on_master", showJSON on_master) |
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, ("on_nodes", showJSON on_nodes) ] |
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in makeObj ol |
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|
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saveOpCode op@(OpInstanceReplaceDisks inst node mode disks iallocator) = |
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let ol = [ ("OP_ID", showJSON $ opID op) |
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, ("instance_name", showJSON inst) |
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, ("mode", showJSON mode) |
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, ("disks", showJSON disks)] |
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ol2 = case node of |
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Just n -> ("remote_node", showJSON n):ol |
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Nothing -> ol |
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ol3 = case iallocator of |
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Just i -> ("iallocator", showJSON i):ol2 |
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Nothing -> ol2 |
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in makeObj ol3 |
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saveOpCode op@(OpInstanceFailover inst consist) = |
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let ol = [ ("OP_ID", showJSON $ opID op) |
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, ("instance_name", showJSON inst) |
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, ("ignore_consistency", showJSON consist) ] |
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in makeObj ol |
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saveOpCode op@(OpInstanceMigrate inst live cleanup allow_failover) = |
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let ol = [ ("OP_ID", showJSON $ opID op) |
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, ("instance_name", showJSON inst) |
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, ("live", showJSON live) |
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, ("cleanup", showJSON cleanup) |
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, ("allow_failover", showJSON allow_failover) ] |
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in makeObj ol |
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instance JSON OpCode where |
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readJSON = loadOpCode |
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showJSON = saveOpCode |