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{-| Implementation of the RAPI client interface.

-}

{-

Copyright (C) 2009, 2010, 2011, 2012 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.

-}

{-# LANGUAGE BangPatterns, CPP #-}

module Ganeti.HTools.Backend.Rapi

  ( loadData

  , parseData

  ) where

import Control.Exception

import Data.List (isPrefixOf)

import Data.Maybe (fromMaybe)

#ifndef NO_CURL

import Network.Curl

import Network.Curl.Types ()

#endif

import Control.Monad

import Text.JSON (JSObject, fromJSObject, decodeStrict)

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

import Text.Printf (printf)

import System.FilePath

import Ganeti.BasicTypes

import Ganeti.HTools.Loader

import Ganeti.HTools.Types

import Ganeti.JSON

import qualified Ganeti.HTools.Group as Group

import qualified Ganeti.HTools.Node as Node

import qualified Ganeti.HTools.Instance as Instance

import qualified Ganeti.Constants as C

{-# ANN module "HLint: ignore Eta reduce" #-}

-- | File method prefix.

filePrefix :: String

filePrefix = "file://"

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

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

#ifdef NO_CURL

getUrl _ = return $ fail "RAPI/curl backend disabled at compile time"

#else

-- | Connection timeout (when using non-file methods).

connTimeout :: Long

connTimeout = 15

-- | The default timeout for queries (when using non-file methods).

queryTimeout :: Long

queryTimeout = 60

-- | The curl options we use.

curlOpts :: [CurlOption]

curlOpts = [ CurlSSLVerifyPeer False

           , CurlSSLVerifyHost 0

           , CurlTimeout queryTimeout

           , CurlConnectTimeout connTimeout

           ]

getUrl url = do

  (code, !body) <- curlGetString url curlOpts

  return (case code of

            CurlOK -> return body

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

                 url (show code))

#endif

-- | Helper to convert I/O errors in 'Bad' values.

ioErrToResult :: IO a -> IO (Result a)

ioErrToResult ioaction =

  Control.Exception.catch (liftM Ok ioaction)

    (\e -> return . Bad . show $ (e::IOException))

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

formatHost :: String -> String

formatHost master =

  if ':' `elem` master

    then  master

    else "https://" ++ master ++ ":" ++ show C.defaultRapiPort

-- | 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

              -> JSRecord

              -> Result (String, Instance.Instance)

parseInstance ktn a = do

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

  let owner_name = "Instance '" ++ name ++ "', error while parsing data"

  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 `mplus` extract "maxmem" 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

  auto_balance <- extract "auto_balance" beparams

  dt <- extract "disk_template" a

  su <- extract "spindle_use" beparams

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

             auto_balance pnode snode dt su

  return (name, inst)

-- | Construct a node from a JSON object.

parseNode :: NameAssoc -> JSRecord -> Result (String, Node.Node)

parseNode ktg a = do

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

  let desc = "Node '" ++ name ++ "', error while parsing data"

      extract s = tryFromObj desc a s

  offline <- extract "offline"

  drained <- extract "drained"

  vm_cap  <- annotateResult desc $ maybeFromObj a "vm_capable"

  let vm_cap' = fromMaybe True vm_cap

  ndparams <- extract "ndparams" >>= asJSObject

  spindles <- tryFromObj desc (fromJSObject ndparams) "spindle_count"

  guuid   <- annotateResult desc $ maybeFromObj a "group.uuid"

  guuid' <-  lookupGroup ktg name (fromMaybe defaultGroupID guuid)

  node <- if offline || drained || not vm_cap'

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

  return (name, node)

-- | Construct a group from a JSON object.

parseGroup :: JSRecord -> 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"

  apol <- extract "alloc_policy"

  ipol <- extract "ipolicy"

  tags <- extract "tags"

  return (uuid, Group.create name uuid apol ipol tags)

-- | Parse cluster data from the info resource.

parseCluster :: JSObject JSValue -> Result ([String], IPolicy)

parseCluster obj = do

  let obj' = fromJSObject obj

      extract s = tryFromObj "Parsing cluster data" obj' s

  tags <- extract "tags"

  ipolicy <- extract "ipolicy"

  return (tags, ipolicy)

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

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

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

readDataHttp 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

  info_body <- getUrl $ printf "%s/2/info" url

  return (group_body, node_body, inst_body, info_body)

-- | Loads the raw cluster data from the filesystem.

readDataFile:: String -- ^ Path to the directory containing the files

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

readDataFile path = do

  group_body <- ioErrToResult . readFile $ path </> "groups.json"

  node_body <- ioErrToResult . readFile $ path </> "nodes.json"

  inst_body <- ioErrToResult . readFile $ path </> "instances.json"

  info_body <- ioErrToResult . readFile $ path </> "info.json"

  return (group_body, node_body, inst_body, info_body)

-- | Loads data via either 'readDataFile' or 'readDataHttp'.

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

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

readData url =

  if filePrefix `isPrefixOf` url

    then readDataFile (drop (length filePrefix) url)

    else readDataHttp url

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

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

          -> Result ClusterData

parseData (group_body, node_body, inst_body, info_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, ipolicy) <- info_body >>=

                     (fromJResult "Parsing cluster info" . decodeStrict) >>=

                     parseCluster

  return (ClusterData group_idx node_idx inst_idx tags ipolicy)

-- | Top level function for data loading.

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

         -> IO (Result ClusterData)

loadData = fmap parseData . readData