root / Ganeti / HTools / IAlloc.hs @ 17e7af2b
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{-| Implementation of the iallocator interface. |
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-} |
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{- |
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Copyright (C) 2009 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.HTools.IAlloc |
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( parseData |
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, formatResponse |
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) where |
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|
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import Data.Either () |
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import Control.Monad |
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import Text.JSON (JSObject, JSValue(JSBool, JSString, JSArray), |
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makeObj, encodeStrict, decodeStrict, |
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fromJSObject, toJSString) |
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import qualified Ganeti.HTools.Container as Container |
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import qualified Ganeti.HTools.Node as Node |
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import qualified Ganeti.HTools.Instance as Instance |
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import Ganeti.HTools.Loader |
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import Ganeti.HTools.Utils |
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import Ganeti.HTools.Types |
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|
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-- | Parse the basic specifications of an instance. |
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-- |
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-- Instances in the cluster instance list and the instance in an |
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-- 'Allocate' request share some common properties, which are read by |
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-- this function. |
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parseBaseInstance :: String |
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-> [(String, JSValue)] |
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-> Result (String, Instance.Instance) |
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parseBaseInstance n a = do |
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disk <- fromObj "disk_space_total" a |
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mem <- fromObj "memory" a |
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vcpus <- fromObj "vcpus" a |
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tags <- fromObj "tags" a |
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let running = "running" |
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return (n, Instance.create n mem disk vcpus running tags 0 0) |
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|
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-- | Parses an instance as found in the cluster instance listg. |
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parseInstance :: NameAssoc -- ^ The node name-to-index association list |
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-> String -- ^ The name of the instance |
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-> [(String, JSValue)] -- ^ The JSON object |
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-> Result (String, Instance.Instance) |
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parseInstance ktn n a = do |
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base <- parseBaseInstance n a |
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nodes <- fromObj "nodes" a |
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pnode <- readEitherString $ head nodes |
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pidx <- lookupNode ktn n pnode |
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let snodes = tail nodes |
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sidx <- (if null snodes then return Node.noSecondary |
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else readEitherString (head snodes) >>= lookupNode ktn n) |
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return (n, Instance.setBoth (snd base) pidx sidx) |
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|
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-- | Parses a node as found in the cluster node list. |
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parseNode :: String -- ^ The node's name |
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-> [(String, JSValue)] -- ^ The JSON object |
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-> Result (String, Node.Node) |
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parseNode n a = do |
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offline <- fromObj "offline" a |
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drained <- fromObj "drained" a |
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node <- (if offline || drained |
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then return $ Node.create n 0 0 0 0 0 0 True |
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else do |
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mtotal <- fromObj "total_memory" a |
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mnode <- fromObj "reserved_memory" a |
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mfree <- fromObj "free_memory" a |
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dtotal <- fromObj "total_disk" a |
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dfree <- fromObj "free_disk" a |
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ctotal <- fromObj "total_cpus" a |
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return $ Node.create n mtotal mnode mfree |
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dtotal dfree ctotal False) |
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return (n, node) |
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-- | Top-level parser. |
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parseData :: String -- ^ The JSON message as received from Ganeti |
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-> Result Request -- ^ A (possible valid) request |
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parseData body = do |
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decoded <- fromJResult $ decodeStrict body |
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let obj = fromJSObject decoded |
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-- request parser |
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request <- liftM fromJSObject (fromObj "request" obj) |
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rname <- fromObj "name" request |
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-- existing node parsing |
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nlist <- liftM fromJSObject (fromObj "nodes" obj) |
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nobj <- mapM (\(x,y) -> asJSObject y >>= parseNode x . fromJSObject) nlist |
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let (ktn, nl) = assignIndices nobj |
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-- existing instance parsing |
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ilist <- fromObj "instances" obj |
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let idata = fromJSObject ilist |
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iobj <- mapM (\(x,y) -> |
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asJSObject y >>= parseInstance ktn x . fromJSObject) idata |
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let (kti, il) = assignIndices iobj |
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(map_n, map_i, csf) <- mergeData [] (nl, il) |
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req_nodes <- fromObj "required_nodes" request |
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optype <- fromObj "type" request |
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rqtype <- |
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case optype of |
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"allocate" -> |
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do |
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inew <- parseBaseInstance rname request |
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let io = snd inew |
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return $ Allocate io req_nodes |
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"relocate" -> |
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do |
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ridx <- lookupInstance kti rname |
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ex_nodes <- fromObj "relocate_from" request |
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let ex_nodes' = map (stripSuffix $ length csf) ex_nodes |
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ex_idex <- mapM (Container.findByName map_n) ex_nodes' |
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return $ Relocate ridx req_nodes (map Node.idx ex_idex) |
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other -> fail ("Invalid request type '" ++ other ++ "'") |
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return $ Request rqtype map_n map_i csf |
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-- | Formats the response into a valid IAllocator response message. |
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formatResponse :: Bool -- ^ Whether the request was successful |
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-> String -- ^ Information text |
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-> [String] -- ^ The list of chosen nodes |
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-> String -- ^ The JSON-formatted message |
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formatResponse success info nodes = |
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let |
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e_success = ("success", JSBool success) |
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e_info = ("info", JSString . toJSString $ info) |
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e_nodes = ("nodes", JSArray $ map (JSString . toJSString) nodes) |
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in encodeStrict $ makeObj [e_success, e_info, e_nodes] |