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{-| Implementation of the RAPI client interface.

-}

{-

Copyright (C) 2009, 2010 Google Inc.

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

02110-1301, USA.

-}

module Ganeti.HTools.Rapi

    (

      loadData

    , parseData

    ) where

import Network.Curl

import Network.Curl.Types ()

import Control.Monad

import Text.JSON (JSObject, JSValue, fromJSObject, decodeStrict)

import Text.JSON.Types (JSValue(..))

import Text.Printf (printf)

import Ganeti.HTools.Utils

import Ganeti.HTools.Loader

import Ganeti.HTools.Types

import qualified Ganeti.HTools.Group as Group

import qualified Ganeti.HTools.Node as Node

import qualified Ganeti.HTools.Instance as Instance

-- | Read an URL via curl and return the body if successful.

getUrl :: (Monad m) => String -> IO (m String)

getUrl url = do

  (code, body) <- curlGetString url [CurlSSLVerifyPeer False,

                                     CurlSSLVerifyHost 0,

                                     CurlTimeout (fromIntegral queryTimeout),

                                     CurlConnectTimeout

                                     (fromIntegral connTimeout)]

  return (case code of

            CurlOK -> return body

            _ -> fail $ printf "Curl error for '%s', error %s"

                 url (show code))

-- | Append the default port if not passed in.

formatHost :: String -> String

formatHost master =

    if ':' `elem` master then  master

    else "https://" ++ master ++ ":5080"

-- | Parse a instance list in JSON format.

getInstances :: NameAssoc

             -> String

             -> Result [(String, Instance.Instance)]

getInstances ktn body =

    loadJSArray "Parsing instance data" body >>=

    mapM (parseInstance ktn . fromJSObject)

-- | Parse a node list in JSON format.

getNodes :: NameAssoc -> String -> Result [(String, Node.Node)]

getNodes ktg body = loadJSArray "Parsing node data" body >>=

                mapM (parseNode ktg . fromJSObject)

-- | Parse a group list in JSON format.

getGroups :: String -> Result [(String, Group.Group)]

getGroups body = loadJSArray "Parsing group data" body >>=

                mapM (parseGroup . fromJSObject)

-- | Construct an instance from a JSON object.

parseInstance :: NameAssoc

              -> [(String, JSValue)]

              -> Result (String, Instance.Instance)

parseInstance ktn a = do

  name <- tryFromObj "Parsing new instance" a "name"

  let owner_name = "Instance '" ++ name ++ "'"

  let extract s x = tryFromObj owner_name x s

  disk <- extract "disk_usage" a

  beparams <- liftM fromJSObject (extract "beparams" a)

  omem <- extract "oper_ram" a

  mem <- (case omem of

            JSRational _ _ -> annotateResult owner_name (fromJVal omem)

            _ -> extract "memory" beparams)

  vcpus <- extract "vcpus" beparams

  pnode <- extract "pnode" a >>= lookupNode ktn name

  snodes <- extract "snodes" a

  snode <- (if null snodes then return Node.noSecondary

            else readEitherString (head snodes) >>= lookupNode ktn name)

  running <- extract "status" a

  tags <- extract "tags" a

  let inst = Instance.create name mem disk vcpus running tags pnode snode

  return (name, inst)

-- | Construct a node from a JSON object.

parseNode :: NameAssoc -> [(String, JSValue)] -> Result (String, Node.Node)

parseNode ktg a = do

  name <- tryFromObj "Parsing new node" a "name"

  let extract s = tryFromObj ("Node '" ++ name ++ "'") a s

  offline <- extract "offline"

  drained <- extract "drained"

  guuid   <- extract "group.uuid" >>= lookupGroup ktg name

  node <- (if offline || drained

           then return $ Node.create name 0 0 0 0 0 0 True guuid

           else do

             mtotal  <- extract "mtotal"

             mnode   <- extract "mnode"

             mfree   <- extract "mfree"

             dtotal  <- extract "dtotal"

             dfree   <- extract "dfree"

             ctotal  <- extract "ctotal"

             return $ Node.create name mtotal mnode mfree

                    dtotal dfree ctotal False guuid)

  return (name, node)

-- | Construct a group from a JSON object.

parseGroup :: [(String, JSValue)] -> Result (String, Group.Group)

parseGroup a = do

  name <- tryFromObj "Parsing new group" a "name"

  let extract s = tryFromObj ("Group '" ++ name ++ "'") a s

  uuid <- extract "uuid"

  return (uuid, Group.create name uuid AllocPreferred)

-- | Loads the raw cluster data from an URL.

readData :: String -- ^ Cluster or URL to use as source

         -> IO (Result String, Result String, Result String, Result String)

readData master = do

  let url = formatHost master

  group_body <- getUrl $ printf "%s/2/groups?bulk=1" url

  node_body <- getUrl $ printf "%s/2/nodes?bulk=1" url

  inst_body <- getUrl $ printf "%s/2/instances?bulk=1" url

  tags_body <- getUrl $ printf "%s/2/tags" url

  return (group_body, node_body, inst_body, tags_body)

-- | Builds the cluster data from the raw Rapi content

parseData :: (Result String, Result String, Result String, Result String)

          -> Result (Group.List, Node.List, Instance.List, [String])

parseData (group_body, node_body, inst_body, tags_body) = do

  group_data <- group_body >>= getGroups

  let (group_names, group_idx) = assignIndices group_data

  node_data <- node_body >>= getNodes group_names

  let (node_names, node_idx) = assignIndices node_data

  inst_data <- inst_body >>= getInstances node_names

  let (_, inst_idx) = assignIndices inst_data

  tags_data <- tags_body >>= (fromJResult "Parsing tags data" . decodeStrict)

  return (group_idx, node_idx, inst_idx, tags_data)

-- | Top level function for data loading

loadData :: String -- ^ Cluster or URL to use as source

            -> IO (Result (Group.List, Node.List, Instance.List, [String]))

loadData master = readData master >>= return . parseData