1 {-| Implementation of the iallocator interface.
7 Copyright (C) 2009, 2010, 2011 Google Inc.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful, but
15 WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
26 module Ganeti.HTools.IAlloc
33 import Data.Maybe (fromMaybe, isJust)
36 import Text.JSON (JSObject, JSValue(JSArray),
37 makeObj, encodeStrict, decodeStrict, fromJSObject, showJSON)
38 import System (exitWith, ExitCode(..))
41 import qualified Ganeti.HTools.Cluster as Cluster
42 import qualified Ganeti.HTools.Container as Container
43 import qualified Ganeti.HTools.Group as Group
44 import qualified Ganeti.HTools.Node as Node
45 import qualified Ganeti.HTools.Instance as Instance
46 import qualified Ganeti.Constants as C
47 import Ganeti.HTools.CLI
48 import Ganeti.HTools.Loader
49 import Ganeti.HTools.ExtLoader (loadExternalData)
50 import Ganeti.HTools.Utils
51 import Ganeti.HTools.Types
53 -- | Type alias for the result of an IAllocator call.
54 type IAllocResult = (String, JSValue, Node.List, Instance.List)
56 -- | Parse the basic specifications of an instance.
58 -- Instances in the cluster instance list and the instance in an
59 -- 'Allocate' request share some common properties, which are read by
61 parseBaseInstance :: String
63 -> Result (String, Instance.Instance)
64 parseBaseInstance n a = do
65 let extract x = tryFromObj ("invalid data for instance '" ++ n ++ "'") a x
66 disk <- extract "disk_space_total"
67 mem <- extract "memory"
68 vcpus <- extract "vcpus"
69 tags <- extract "tags"
70 dt <- extract "disk_template"
71 let running = "running"
72 return (n, Instance.create n mem disk vcpus running tags True 0 0 dt)
74 -- | Parses an instance as found in the cluster instance list.
75 parseInstance :: NameAssoc -- ^ The node name-to-index association list
76 -> String -- ^ The name of the instance
77 -> JSRecord -- ^ The JSON object
78 -> Result (String, Instance.Instance)
79 parseInstance ktn n a = do
80 base <- parseBaseInstance n a
81 nodes <- fromObj a "nodes"
82 pnode <- if null nodes
83 then Bad $ "empty node list for instance " ++ n
84 else readEitherString $ head nodes
85 pidx <- lookupNode ktn n pnode
86 let snodes = tail nodes
87 sidx <- (if null snodes then return Node.noSecondary
88 else readEitherString (head snodes) >>= lookupNode ktn n)
89 return (n, Instance.setBoth (snd base) pidx sidx)
91 -- | Parses a node as found in the cluster node list.
92 parseNode :: NameAssoc -- ^ The group association
93 -> String -- ^ The node's name
94 -> JSRecord -- ^ The JSON object
95 -> Result (String, Node.Node)
96 parseNode ktg n a = do
97 let desc = "invalid data for node '" ++ n ++ "'"
98 extract x = tryFromObj desc a x
99 offline <- extract "offline"
100 drained <- extract "drained"
101 guuid <- extract "group"
102 vm_capable <- annotateResult desc $ maybeFromObj a "vm_capable"
103 let vm_capable' = fromMaybe True vm_capable
104 gidx <- lookupGroup ktg n guuid
105 node <- (if offline || drained || not vm_capable'
106 then return $ Node.create n 0 0 0 0 0 0 True gidx
108 mtotal <- extract "total_memory"
109 mnode <- extract "reserved_memory"
110 mfree <- extract "free_memory"
111 dtotal <- extract "total_disk"
112 dfree <- extract "free_disk"
113 ctotal <- extract "total_cpus"
114 return $ Node.create n mtotal mnode mfree
115 dtotal dfree ctotal False gidx)
118 -- | Parses a group as found in the cluster group list.
119 parseGroup :: String -- ^ The group UUID
120 -> JSRecord -- ^ The JSON object
121 -> Result (String, Group.Group)
123 let extract x = tryFromObj ("invalid data for group '" ++ u ++ "'") a x
124 name <- extract "name"
125 apol <- extract "alloc_policy"
126 return (u, Group.create name u apol)
128 -- | Top-level parser.
130 -- The result is a tuple of eventual warning messages and the parsed
131 -- request; if parsing the input data fails, we'll return a 'Bad'
133 parseData :: String -- ^ The JSON message as received from Ganeti
134 -> Result ([String], Request) -- ^ Result tuple
136 decoded <- fromJResult "Parsing input IAllocator message" (decodeStrict body)
137 let obj = fromJSObject decoded
138 extrObj x = tryFromObj "invalid iallocator message" obj x
140 request <- liftM fromJSObject (extrObj "request")
141 let extrReq x = tryFromObj "invalid request dict" request x
142 -- existing group parsing
143 glist <- liftM fromJSObject (extrObj "nodegroups")
144 gobj <- mapM (\(x, y) -> asJSObject y >>= parseGroup x . fromJSObject) glist
145 let (ktg, gl) = assignIndices gobj
146 -- existing node parsing
147 nlist <- liftM fromJSObject (extrObj "nodes")
148 nobj <- mapM (\(x,y) ->
149 asJSObject y >>= parseNode ktg x . fromJSObject) nlist
150 let (ktn, nl) = assignIndices nobj
151 -- existing instance parsing
152 ilist <- extrObj "instances"
153 let idata = fromJSObject ilist
154 iobj <- mapM (\(x,y) ->
155 asJSObject y >>= parseInstance ktn x . fromJSObject) idata
156 let (kti, il) = assignIndices iobj
158 ctags <- extrObj "cluster_tags"
159 cdata1 <- mergeData [] [] [] [] (ClusterData gl nl il ctags)
160 let (msgs, fix_nl) = checkData (cdNodes cdata1) (cdInstances cdata1)
161 cdata = cdata1 { cdNodes = fix_nl }
162 map_n = cdNodes cdata
163 map_i = cdInstances cdata
164 map_g = cdGroups cdata
165 optype <- extrReq "type"
168 _ | optype == C.iallocatorModeAlloc ->
170 rname <- extrReq "name"
171 req_nodes <- extrReq "required_nodes"
172 inew <- parseBaseInstance rname request
174 return $ Allocate io req_nodes
175 | optype == C.iallocatorModeReloc ->
177 rname <- extrReq "name"
178 ridx <- lookupInstance kti rname
179 req_nodes <- extrReq "required_nodes"
180 ex_nodes <- extrReq "relocate_from"
181 ex_idex <- mapM (Container.findByName map_n) ex_nodes
182 return $ Relocate ridx req_nodes (map Node.idx ex_idex)
183 | optype == C.iallocatorModeChgGroup ->
185 rl_names <- extrReq "instances"
186 rl_insts <- mapM (liftM Instance.idx .
187 Container.findByName map_i) rl_names
188 gr_uuids <- extrReq "target_groups"
189 gr_idxes <- mapM (liftM Group.idx .
190 Container.findByName map_g) gr_uuids
191 return $ ChangeGroup rl_insts gr_idxes
192 | optype == C.iallocatorModeNodeEvac ->
194 rl_names <- extrReq "instances"
195 rl_insts <- mapM (Container.findByName map_i) rl_names
196 let rl_idx = map Instance.idx rl_insts
197 rl_mode <- extrReq "evac_mode"
198 return $ NodeEvacuate rl_idx rl_mode
200 | otherwise -> fail ("Invalid request type '" ++ optype ++ "'")
201 return (msgs, Request rqtype cdata)
203 -- | Formats the result into a valid IAllocator response message.
204 formatResponse :: Bool -- ^ Whether the request was successful
205 -> String -- ^ Information text
206 -> JSValue -- ^ The JSON encoded result
207 -> String -- ^ The full JSON-formatted message
208 formatResponse success info result =
210 e_success = ("success", showJSON success)
211 e_info = ("info", showJSON info)
212 e_result = ("result", result)
213 in encodeStrict $ makeObj [e_success, e_info, e_result]
215 -- | Flatten the log of a solution into a string.
216 describeSolution :: Cluster.AllocSolution -> String
217 describeSolution = intercalate ", " . Cluster.asLog
219 -- | Convert allocation/relocation results into the result format.
220 formatAllocate :: Instance.List -> Cluster.AllocSolution -> Result IAllocResult
221 formatAllocate il as = do
222 let info = describeSolution as
223 case Cluster.asSolution as of
225 Just (nl, inst, nodes, _) ->
227 let il' = Container.add (Instance.idx inst) inst il
228 return (info, showJSON $ map Node.name nodes, nl, il')
230 -- | Convert a node-evacuation/change group result.
231 formatNodeEvac :: Group.List
234 -> (Node.List, Instance.List, Cluster.EvacSolution)
235 -> Result IAllocResult
236 formatNodeEvac gl nl il (fin_nl, fin_il, es) =
237 let iname = Instance.name . flip Container.find il
238 nname = Node.name . flip Container.find nl
239 gname = Group.name . flip Container.find gl
240 fes = map (\(idx, msg) -> (iname idx, msg)) $ Cluster.esFailed es
241 mes = map (\(idx, gdx, ndxs) -> (iname idx, gname gdx, map nname ndxs))
245 info = show failed ++ " instances failed to move and " ++ show moved ++
246 " were moved successfully"
247 in Ok (info, showJSON (mes, fes, Cluster.esOpCodes es), fin_nl, fin_il)
249 -- | Runs relocate for a single instance.
251 -- This is wrapper over the 'Cluster.tryNodeEvac' function that is run
252 -- with a single instance (ours), and further it checks that the
253 -- result it got (in the nodes field) is actually consistent, as
254 -- tryNodeEvac is designed to output primarily an opcode list, not a
256 processRelocate :: Group.List -- ^ The group list
257 -> Node.List -- ^ The node list
258 -> Instance.List -- ^ The instance list
259 -> Idx -- ^ The index of the instance to move
260 -> Int -- ^ The number of nodes required
261 -> [Ndx] -- ^ Nodes which should not be used
262 -> Result (Node.List, Instance.List, [Ndx]) -- ^ Solution list
263 processRelocate gl nl il idx 1 exndx = do
264 let orig = Container.find idx il
265 sorig = Instance.sNode orig
266 when (exndx /= [sorig]) $
267 -- FIXME: we can't use the excluded nodes here; the logic is
268 -- already _but only partially_ implemented in tryNodeEvac...
269 fail $ "Unsupported request: excluded nodes not equal to\
270 \ instance's secondary node (" ++ show sorig ++ " versus " ++
272 (nl', il', esol) <- Cluster.tryNodeEvac gl nl il ChangeSecondary [idx]
273 nodes <- case lookup idx (Cluster.esFailed esol) of
276 case lookup idx (map (\(a, _, b) -> (a, b))
277 (Cluster.esMoved esol)) of
279 fail "Internal error: lost instance idx during move"
281 let inst = Container.find idx il'
282 pnode = Instance.pNode inst
283 snode = Instance.sNode inst
284 when (snode == sorig) $
285 fail "Internal error: instance didn't change secondary node?!"
286 when (snode == pnode) $
287 fail "Internal error: selected primary as new secondary?!"
289 nodes' <- if nodes == [pnode, snode]
290 then return [snode] -- only the new secondary is needed
291 else fail $ "Internal error: inconsistent node list (" ++
292 show nodes ++ ") versus instance nodes (" ++ show pnode ++
293 "," ++ show snode ++ ")"
294 return (nl', il', nodes')
296 processRelocate _ _ _ _ reqn _ =
297 fail $ "Exchange " ++ show reqn ++ " nodes mode is not implemented"
299 formatRelocate :: (Node.List, Instance.List, [Ndx])
300 -> Result IAllocResult
301 formatRelocate (nl, il, ndxs) =
302 let nodes = map (`Container.find` nl) ndxs
303 names = map Node.name nodes
304 in Ok ("success", showJSON names, nl, il)
306 -- | Process a request and return new node lists.
307 processRequest :: Request -> Result IAllocResult
308 processRequest request =
309 let Request rqtype (ClusterData gl nl il _) = request
312 Cluster.tryMGAlloc gl nl il xi reqn >>= formatAllocate il
313 Relocate idx reqn exnodes ->
314 processRelocate gl nl il idx reqn exnodes >>= formatRelocate
315 ChangeGroup gdxs idxs ->
316 Cluster.tryChangeGroup gl nl il idxs gdxs >>=
317 formatNodeEvac gl nl il
318 NodeEvacuate xi mode ->
319 Cluster.tryNodeEvac gl nl il mode xi >>=
320 formatNodeEvac gl nl il
322 -- | Reads the request from the data file(s).
323 readRequest :: Options -> [String] -> IO Request
324 readRequest opts args = do
325 when (null args) $ do
326 hPutStrLn stderr "Error: this program needs an input file."
327 exitWith $ ExitFailure 1
329 input_data <- readFile (head args)
330 r1 <- case parseData input_data of
332 hPutStrLn stderr $ "Error: " ++ err
333 exitWith $ ExitFailure 1
334 Ok (fix_msgs, rq) -> maybeShowWarnings fix_msgs >> return rq
335 (if isJust (optDataFile opts) || (not . null . optNodeSim) opts
337 cdata <- loadExternalData opts
338 let Request rqt _ = r1
339 return $ Request rqt cdata
342 -- | Main iallocator pipeline.
343 runIAllocator :: Request -> (Maybe (Node.List, Instance.List), String)
344 runIAllocator request =
345 let (ok, info, result, cdata) =
346 case processRequest request of
347 Ok (msg, r, nl, il) -> (True, "Request successful: " ++ msg, r,
349 Bad msg -> (False, "Request failed: " ++ msg, JSArray [], Nothing)
350 rstring = formatResponse ok info result