git-annex/Remote/Hook.hs
Joey Hess 61dbad505d fsck --from remote --fast
Avoids expensive file transfers, at the expense of checking file size
and/or contents.

Required some reworking of the remote code.
2012-01-20 13:23:11 -04:00

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{- A remote that provides hooks to run shell commands.
-
- Copyright 2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Remote.Hook (remote) where
import qualified Data.ByteString.Lazy.Char8 as L
import qualified Data.Map as M
import System.Exit
import Common.Annex
import Types.Remote
import qualified Git
import Config
import Annex.Content
import Remote.Helper.Special
import Remote.Helper.Encryptable
import Crypto
remote :: RemoteType
remote = RemoteType {
typename = "hook",
enumerate = findSpecialRemotes "hooktype",
generate = gen,
setup = hookSetup
}
gen :: Git.Repo -> UUID -> Maybe RemoteConfig -> Annex Remote
gen r u c = do
hooktype <- getConfig r "hooktype" (error "missing hooktype")
cst <- remoteCost r expensiveRemoteCost
return $ encryptableRemote c
(storeEncrypted hooktype)
(retrieveEncrypted hooktype)
Remote {
uuid = u,
cost = cst,
name = Git.repoDescribe r,
storeKey = store hooktype,
retrieveKeyFile = retrieve hooktype,
retrieveKeyFileCheap = retrieveCheap hooktype,
removeKey = remove hooktype,
hasKey = checkPresent r hooktype,
hasKeyCheap = False,
config = Nothing,
repo = r,
remotetype = remote
}
hookSetup :: UUID -> RemoteConfig -> Annex RemoteConfig
hookSetup u c = do
let hooktype = fromMaybe (error "Specify hooktype=") $
M.lookup "hooktype" c
c' <- encryptionSetup c
gitConfigSpecialRemote u c' "hooktype" hooktype
return c'
hookEnv :: Key -> Maybe FilePath -> Maybe [(String, String)]
hookEnv k f = Just $ fileenv f ++ keyenv
where
env s v = ("ANNEX_" ++ s, v)
keyenv =
[ env "KEY" (show k)
, env "HASH_1" (hashbits !! 0)
, env "HASH_2" (hashbits !! 1)
]
fileenv Nothing = []
fileenv (Just file) = [env "FILE" file]
hashbits = map takeDirectory $ splitPath $ hashDirMixed k
lookupHook :: String -> String -> Annex (Maybe String)
lookupHook hooktype hook =do
g <- gitRepo
command <- getConfig g hookname ""
if null command
then do
warning $ "missing configuration for " ++ hookname
return Nothing
else return $ Just command
where
hookname = hooktype ++ "-" ++ hook ++ "-hook"
runHook :: String -> String -> Key -> Maybe FilePath -> Annex Bool -> Annex Bool
runHook hooktype hook k f a = maybe (return False) run =<< lookupHook hooktype hook
where
run command = do
showOutput -- make way for hook output
res <- liftIO $ boolSystemEnv
"sh" [Param "-c", Param command] $ hookEnv k f
if res
then a
else do
warning $ hook ++ " hook exited nonzero!"
return res
store :: String -> Key -> Annex Bool
store h k = do
src <- inRepo $ gitAnnexLocation k
runHook h "store" k (Just src) $ return True
storeEncrypted :: String -> (Cipher, Key) -> Key -> Annex Bool
storeEncrypted h (cipher, enck) k = withTmp enck $ \tmp -> do
src <- inRepo $ gitAnnexLocation k
liftIO $ withEncryptedContent cipher (L.readFile src) $ L.writeFile tmp
runHook h "store" enck (Just tmp) $ return True
retrieve :: String -> Key -> FilePath -> Annex Bool
retrieve h k f = runHook h "retrieve" k (Just f) $ return True
retrieveCheap :: String -> Key -> FilePath -> Annex Bool
retrieveCheap _ _ _ = return False
retrieveEncrypted :: String -> (Cipher, Key) -> FilePath -> Annex Bool
retrieveEncrypted h (cipher, enck) f = withTmp enck $ \tmp ->
runHook h "retrieve" enck (Just tmp) $ liftIO $ catchBoolIO $ do
withDecryptedContent cipher (L.readFile tmp) $ L.writeFile f
return True
remove :: String -> Key -> Annex Bool
remove h k = runHook h "remove" k Nothing $ return True
checkPresent :: Git.Repo -> String -> Key -> Annex (Either String Bool)
checkPresent r h k = do
showAction $ "checking " ++ Git.repoDescribe r
v <- lookupHook h "checkpresent"
liftIO $ catchMsgIO $ check v
where
findkey s = show k `elem` lines s
env = hookEnv k Nothing
check Nothing = error "checkpresent hook misconfigured"
check (Just hook) = do
(frompipe, topipe) <- createPipe
pid <- forkProcess $ do
_ <- dupTo topipe stdOutput
closeFd frompipe
executeFile "sh" True ["-c", hook] env
closeFd topipe
fromh <- fdToHandle frompipe
reply <- hGetContentsStrict fromh
hClose fromh
s <- getProcessStatus True False pid
case s of
Just (Exited ExitSuccess) -> return $ findkey reply
_ -> error "checkpresent hook failed"