src/Ganeti/Confd/ClientFunctions.hs

{-| Some utility functions, based on the Confd client, providing data
 in a ready-to-use way.
-}

{-

Copyright (C) 2013 Google Inc.
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-}

module Ganeti.Confd.ClientFunctions
  ( getInstances
  ) where

import qualified Text.JSON as J

import Ganeti.BasicTypes as BT
import Ganeti.Confd.Types
import Ganeti.Confd.Client
import Ganeti.Objects


-- | Get the list of instances the given node is ([primary], [secondary]) for.
-- The server address and the server port parameters are mainly intended
-- for testing purposes. If they are Nothing, the default values will be used.
getInstances
  :: String
  -> Maybe String
  -> Maybe Int
  -> IO (BT.Result ([Ganeti.Objects.Instance], [Ganeti.Objects.Instance]))
getInstances node srvAddr srvPort = do
  client <- getConfdClient srvAddr srvPort
  reply <- query client ReqNodeInstances $ PlainQuery node
  return $
    case fmap (J.readJSON . confdReplyAnswer) reply of
      Just (J.Ok instances) -> BT.Ok instances
      Just (J.Error msg) -> BT.Bad msg
      Nothing -> BT.Bad "No answer from the Confd server"