src/Ganeti/HTools/Cluster/AllocateSecondary.hs

{-| Implementation of finding a secondary for disk template conversion

-}

{-

Copyright (C) 2015 Google Inc.
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-}

module Ganeti.HTools.Cluster.AllocateSecondary
  ( tryAllocateSecondary
  ) where

import Control.Monad (unless)

import Ganeti.BasicTypes
import Ganeti.HTools.AlgorithmParams (AlgorithmOptions(..))
import qualified Ganeti.HTools.Cluster as Cluster
import Ganeti.HTools.Cluster.AllocationSolution (AllocSolution)
import qualified Ganeti.HTools.Container as Container
import qualified Ganeti.HTools.Group as Group
import qualified Ganeti.HTools.Instance as Instance
import qualified Ganeti.HTools.Node as Node
import Ganeti.HTools.Types

tryAllocateSecondary :: AlgorithmOptions
                     -> Group.List    -- ^ The cluster groups
                     -> Node.List     -- ^ The node list (cluster-wide,
                                      -- not per group)
                     -> Instance.List -- ^ Instance list (cluster-wide)
                     -> Idx
                     -> Result AllocSolution
tryAllocateSecondary opts _ nl il idx = do
  let inst = Container.find idx il
  unless (Instance.sNode inst < 0)
    $ fail "Instance already has a secondary"
  let pidx = Instance.pNode inst
      pnode = Container.find pidx nl
      pnode' = Node.removePri pnode inst
      nl' = Container.add pidx pnode' nl
      inst' = inst { Instance.diskTemplate = DTDrbd8 }
      gidx = Node.group pnode'
      sidxs = filter (/= pidx) . Container.keys
              $ Container.filter ((==) gidx . Node.group) nl'
  Cluster.tryAlloc opts nl' il inst' $ Right [(pidx, sidxs)]