git-annex/Remote/GitLFS.hs

449 lines
16 KiB
Haskell

{- Using git-lfs as a remote.
-
- Copyright 2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Remote.GitLFS (remote, gen) where
import Annex.Common
import Types.Remote
import Annex.Url
import Types.Key
import Types.Creds
import qualified Annex
import qualified Git
import qualified Git.Types as Git
import qualified Git.Url
import qualified Git.GCrypt
import Config
import Config.Cost
import Remote.Helper.Special
import Remote.Helper.ExportImport
import Remote.Helper.Git
import Remote.Helper.Http
import qualified Remote.GCrypt
import Annex.Ssh
import Annex.UUID
import Crypto
import Backend.Hash
import Utility.Hash
import Utility.SshHost
import Logs.RemoteState
import qualified Utility.GitLFS as LFS
import Control.Concurrent.STM
import Data.String
import Network.HTTP.Types
import Network.HTTP.Client hiding (port)
import System.Log.Logger
import qualified Data.Map as M
import qualified Data.ByteString.Lazy as L
import qualified Data.Text as T
import qualified Data.Text.Encoding as E
remote :: RemoteType
remote = RemoteType
{ typename = "git-lfs"
-- Remote.Git takes care of enumerating git-lfs remotes too,
-- and will call our gen on them.
, enumerate = const (return [])
, generate = gen
, setup = mySetup
, exportSupported = exportUnsupported
, importSupported = importUnsupported
}
gen :: Git.Repo -> UUID -> RemoteConfig -> RemoteGitConfig -> Annex (Maybe Remote)
gen r u c gc = do
-- If the repo uses gcrypt, get the underlaying repo without the
-- gcrypt url, to do LFS endpoint discovery on.
r' <- if Git.GCrypt.isEncrypted r
then do
g <- Annex.gitRepo
liftIO $ Git.GCrypt.encryptedRemote g r
else pure r
h <- liftIO $ newTVarIO $ LFSHandle Nothing Nothing r' gc
cst <- remoteCost gc expensiveRemoteCost
return $ Just $ specialRemote' specialcfg c
(simplyPrepare $ store u h)
(simplyPrepare $ retrieve u h)
(simplyPrepare $ remove h)
(simplyPrepare $ checkKey u h)
(this cst)
where
this cst = Remote
{ uuid = u
, cost = cst
, name = Git.repoDescribe r
, storeKey = storeKeyDummy
, retrieveKeyFile = retreiveKeyFileDummy
, retrieveKeyFileCheap = retrieveCheap
-- content stored on git-lfs is hashed with SHA256
-- no matter what git-annex key it's for, and the hash
-- is checked on download
, retrievalSecurityPolicy = RetrievalAllKeysSecure
, removeKey = removeKeyDummy
, lockContent = Nothing
, checkPresent = checkPresentDummy
, checkPresentCheap = False
, exportActions = exportUnsupported
, importActions = importUnsupported
, whereisKey = Nothing
, remoteFsck = Nothing
, repairRepo = Nothing
, config = c
, getRepo = return r
, gitconfig = gc
, localpath = Nothing
, remotetype = remote
, availability = GloballyAvailable
, readonly = False
-- content cannot be removed from a git-lfs repo
, appendonly = True
, mkUnavailable = return Nothing
, getInfo = gitRepoInfo (this cst)
, claimUrl = Nothing
, checkUrl = Nothing
}
specialcfg = (specialRemoteCfg c)
-- chunking would not improve git-lfs
{ chunkConfig = NoChunks
}
mySetup :: SetupStage -> Maybe UUID -> Maybe CredPair -> RemoteConfig -> RemoteGitConfig -> Annex (RemoteConfig, UUID)
mySetup _ mu _ c gc = do
u <- maybe (liftIO genUUID) return mu
(c', _encsetup) <- encryptionSetup c gc
case (isEncrypted c', Git.GCrypt.urlPrefix `isPrefixOf` url) of
(False, False) -> noop
(True, True) -> Remote.GCrypt.setGcryptEncryption c' remotename
(True, False) -> unlessM (Annex.getState Annex.force) $
giveup $ unwords $
[ "Encryption is enabled for this remote,"
, "but only the files that git-annex stores on"
, "it would be encrypted; "
, "anything that git push sends to it would"
, "not be encrypted. Recommend prefixing the"
, "url with \"gcrypt::\" to also encrypt"
, "git pushes."
, "(Use --force if you want to use this"
, "likely insecure configuration.)"
]
(False, True) -> unlessM (Annex.getState Annex.force) $
giveup $ unwords $
[ "You used a \"gcrypt::\" url for this remote,"
, "but encryption=none prevents git-annex"
, "from encrypting files it stores there."
, "(Use --force if you want to use this"
, "likely insecure configuration.)"
]
-- The url is not stored in the remote log, because the same
-- git-lfs repo can be accessed using different urls by different
-- people (eg over ssh or http).
--
-- Instead, set up remote.name.url to point to the repo,
-- (so it's also usable by git as a non-special remote),
-- and set remote.name.git-lfs = true
let c'' = M.delete "url" c'
gitConfigSpecialRemote u c'' [("git-lfs", "true")]
setConfig (ConfigKey ("remote." ++ getRemoteName c ++ ".url")) url
return (c'', u)
where
url = fromMaybe (giveup "Specify url=") (M.lookup "url" c)
remotename = fromJust (M.lookup "name" c)
data LFSHandle = LFSHandle
{ downloadEndpoint :: Maybe LFS.Endpoint
, uploadEndpoint :: Maybe LFS.Endpoint
, remoteRepo :: Git.Repo
, remoteGitConfig :: RemoteGitConfig
}
discoverLFSEndpoint :: LFS.TransferRequestOperation -> LFSHandle -> Annex (Maybe LFS.Endpoint)
discoverLFSEndpoint tro h
| Git.repoIsSsh r = gossh
| Git.repoIsHttp r = gohttp
| otherwise = do
warning "git-lfs endpoint has unsupported URI scheme"
return Nothing
where
r = remoteRepo h
lfsrepouri = case Git.location r of
Git.Url u -> u
_ -> giveup $ "unsupported git-lfs remote location " ++ Git.repoLocation r
gohttp = case tro of
LFS.RequestDownload -> return $ LFS.guessEndpoint lfsrepouri
LFS.RequestUpload -> do
-- git-lfs does support storing over http,
-- but it would need prompting for http basic
-- authentication each time git-annex discovered
-- the endpoint.
warning "Storing content in git-lfs currently needs a ssh repository url, not http."
return Nothing
gossh = case mkSshHost <$> Git.Url.hostuser r of
Nothing -> do
warning "Unable to parse ssh url for git-lfs remote."
return Nothing
Just (Left err) -> do
warning err
return Nothing
Just (Right hostuser) -> do
let port = Git.Url.port r
-- Remove leading /~/ from path. That is added when
-- converting a scp-style repository location with
-- a relative path into an url, and is legal
-- according to git-clone(1), but github does not
-- support it.
let remotepath = if "/~/" `isPrefixOf` Git.Url.path r
then drop 3 (Git.Url.path r)
else Git.Url.path r
let ps = LFS.sshDiscoverEndpointCommand remotepath tro
-- Note that no shellEscape is done here, because
-- at least github's git-lfs implementation does
-- not allow for shell quoting.
let remotecmd = unwords ps
(sshcommand, sshparams) <- sshCommand NoConsumeStdin (hostuser, port) (remoteGitConfig h) remotecmd
liftIO (tryIO (readProcess sshcommand (toCommand sshparams))) >>= \case
Left err -> do
warning $ "ssh connection to git-lfs remote failed: " ++ show err
return Nothing
Right resp -> case LFS.parseSshDiscoverEndpointResponse (fromString resp) of
Nothing -> do
warning $ "unexpected response from git-lfs remote when doing ssh endpoint discovery"
return Nothing
Just endpoint -> return (Just endpoint)
-- The endpoint is cached for later use.
getLFSEndpoint :: LFS.TransferRequestOperation -> TVar LFSHandle -> Annex (Maybe LFS.Endpoint)
getLFSEndpoint tro hv = do
h <- liftIO $ atomically $ readTVar hv
case f h of
Just endpoint -> return (Just endpoint)
Nothing -> discoverLFSEndpoint tro h >>= \case
Just endpoint -> do
liftIO $ atomically $ writeTVar hv $
case tro of
LFS.RequestDownload ->
h { downloadEndpoint = Just endpoint }
LFS.RequestUpload ->
h { uploadEndpoint = Just endpoint }
return (Just endpoint)
Nothing -> return Nothing
where
f = case tro of
LFS.RequestDownload -> downloadEndpoint
LFS.RequestUpload -> uploadEndpoint
-- Make an API request that is expected to have a small response body.
-- Not for use in downloading an object.
makeSmallAPIRequest :: Request -> Annex (Response L.ByteString)
makeSmallAPIRequest req = do
uo <- getUrlOptions
let req' = applyRequest uo req
liftIO $ debugM "git-lfs" (show req')
resp <- liftIO $ httpLbs req' (httpManager uo)
-- Only debug the http status code, not the json
-- which may include an authentication token.
liftIO $ debugM "git-lfs" (show $ responseStatus resp)
return resp
sendTransferRequest
:: LFS.IsTransferResponseOperation op
=> LFS.TransferRequest
-> LFS.Endpoint
-> Annex (Either String (LFS.TransferResponse op))
sendTransferRequest req endpoint =
case LFS.startTransferRequest endpoint req of
Just httpreq -> do
httpresp <- makeSmallAPIRequest $ setRequestCheckStatus httpreq
return $ case LFS.parseTransferResponse (responseBody httpresp) of
LFS.ParsedTransferResponse resp -> Right resp
LFS.ParsedTransferResponseError tro -> Left $
T.unpack $ LFS.resperr_message tro
LFS.ParseFailed err -> Left err
Nothing -> return $ Left "unable to parse git-lfs endpoint url"
extractKeySha256 :: Key -> Maybe LFS.SHA256
extractKeySha256 k = case keyVariety k of
SHA2Key (HashSize 256) (HasExt hasext)
| hasext -> eitherToMaybe $ E.decodeUtf8' (keyHash k)
| otherwise -> eitherToMaybe $ E.decodeUtf8' (keyName k)
_ -> Nothing
-- The size of an encrypted key is the size of the input data, but we need
-- the actual object size.
extractKeySize :: Key -> Maybe Integer
extractKeySize k
| isEncKey k = Nothing
| otherwise = keySize k
mkUploadRequest :: UUID -> Key -> FilePath -> Annex (LFS.TransferRequest, LFS.SHA256, Integer)
mkUploadRequest u k content = case (extractKeySha256 k, extractKeySize k) of
(Just sha256, Just size) ->
ret sha256 size
(_, Just size) -> do
sha256 <- calcsha256
remembersha256 sha256
ret sha256 size
_ -> do
sha256 <- calcsha256
size <- liftIO $ getFileSize content
rememberboth sha256 size
ret sha256 size
where
calcsha256 = liftIO $ T.pack . show . sha2_256 <$> L.readFile content
ret sha256 size = do
let obj = LFS.TransferRequestObject
{ LFS.req_oid = sha256
, LFS.req_size = size
}
let req = LFS.TransferRequest
{ LFS.req_operation = LFS.RequestUpload
, LFS.req_transfers = [LFS.Basic]
, LFS.req_ref = Nothing
, LFS.req_objects = [obj]
}
return (req, sha256, size)
remembersha256 sha256 = setRemoteState u k (T.unpack sha256)
rememberboth sha256 size = setRemoteState u k $
show size ++ " " ++ T.unpack sha256
mkDownloadRequest :: UUID -> Key -> Annex (Maybe (LFS.TransferRequest, LFS.SHA256, Integer))
mkDownloadRequest u k = case (extractKeySha256 k, extractKeySize k) of
(Just sha256, Just size) -> ret sha256 size
(_, Just size) ->
remembersha256 >>= \case
Just sha256 -> ret sha256 size
Nothing -> return Nothing
_ -> do
rememberboth >>= \case
Just (sha256, size) -> ret sha256 size
Nothing -> return Nothing
where
ret sha256 size = do
let obj = LFS.TransferRequestObject
{ LFS.req_oid = sha256
, LFS.req_size = size
}
let req = LFS.TransferRequest
{ LFS.req_operation = LFS.RequestDownload
, LFS.req_transfers = [LFS.Basic]
, LFS.req_ref = Nothing
, LFS.req_objects = [obj]
}
return $ Just (req, sha256, size)
remembersha256 = fmap T.pack <$> getRemoteState u k
rememberboth = maybe Nothing parse <$> getRemoteState u k
where
parse s = case words s of
[ssize, ssha256] -> do
size <- readish ssize
return (T.pack ssha256, size)
_ -> Nothing
store :: UUID -> TVar LFSHandle -> Storer
store u h = fileStorer $ \k src p -> getLFSEndpoint LFS.RequestUpload h >>= \case
Nothing -> return False
Just endpoint -> flip catchNonAsync failederr $ do
(req, sha256, size) <- mkUploadRequest u k src
sendTransferRequest req endpoint >>= \case
Left err -> do
warning err
return False
Right resp -> do
body <- liftIO $ httpBodyStorer src p
forM_ (LFS.objects resp) $
send body sha256 size
return True
where
send body sha256 size tro
| LFS.resp_oid tro /= sha256 || LFS.resp_size tro /= size =
giveup "git-lfs server requested other object than the one we asked to send"
| otherwise = case LFS.resp_error tro of
Just err -> giveup $
T.unpack $ LFS.respobjerr_message err
Nothing -> case LFS.resp_actions tro of
Nothing -> noop
Just op -> case LFS.uploadOperationRequests op body sha256 size of
Nothing -> giveup "unable to parse git-lfs server upload url"
Just [] -> noop -- server already has it
Just reqs -> forM_ reqs $
makeSmallAPIRequest . setRequestCheckStatus
failederr e = do
warning (show e)
return False
retrieve :: UUID -> TVar LFSHandle -> Retriever
retrieve u h = fileRetriever $ \dest k p -> getLFSEndpoint LFS.RequestDownload h >>= \case
Nothing -> giveup "unable to connect to git-lfs endpoint"
Just endpoint -> mkDownloadRequest u k >>= \case
Nothing -> giveup "unable to download this object from git-lfs"
Just (req, sha256, size) -> sendTransferRequest req endpoint >>= \case
Left err -> giveup (show err)
Right resp -> case LFS.objects resp of
[] -> giveup "git-lfs server did not provide a way to download this object"
(tro:_)
| LFS.resp_oid tro /= sha256 || LFS.resp_size tro /= size ->
giveup "git-lfs server replied with other object than the one we requested"
| otherwise -> go dest p tro
where
go dest p tro = case LFS.resp_error tro of
Just err -> giveup $ T.unpack $ LFS.respobjerr_message err
Nothing -> case LFS.resp_actions tro of
Nothing -> giveup "git-lfs server did not provide a way to download this object"
Just op -> case LFS.downloadOperationRequest op of
Nothing -> giveup "unable to parse git-lfs server download url"
Just req -> do
uo <- getUrlOptions
liftIO $ downloadConduit p req dest uo
checkKey :: UUID -> TVar LFSHandle -> CheckPresent
checkKey u h key = getLFSEndpoint LFS.RequestDownload h >>= \case
Nothing -> giveup "unable to connect to git-lfs endpoint"
Just endpoint -> mkDownloadRequest u key >>= \case
-- Unable to find enough information to request the key
-- from git-lfs, so it's not present there.
Nothing -> return False
Just (req, sha256, size) -> case LFS.startTransferRequest endpoint req of
Nothing -> giveup "unable to parse git-lfs endpoint url"
Just httpreq -> go sha256 size =<< makeSmallAPIRequest httpreq
where
go sha256 size httpresp
| responseStatus httpresp == status200 = go' sha256 size $
LFS.parseTransferResponse (responseBody httpresp)
| otherwise = giveup $
"git-lfs server refused request: " ++ show (responseStatus httpresp)
go' :: LFS.SHA256 -> Integer -> LFS.ParsedTransferResponse LFS.DownloadOperation -> Annex Bool
go' _ _ (LFS.ParseFailed err) =
giveup $ "unable to parse response from git-lfs server: " ++ err
-- If the server responds with a json error message,
-- the content is presumably not present.
go' _ _ (LFS.ParsedTransferResponseError _) = return False
-- If the server responds with at least one download operation,
-- we will assume the content is present. We could also try to HEAD
-- that download, but there's no guarantee HEAD is supported, and
-- at most that would detect breakage where the server is confused
-- about what objects it has.
go' sha256 size (LFS.ParsedTransferResponse resp) =
case LFS.objects resp of
[] -> return False
(tro:_)
| isNothing (LFS.resp_actions tro) -> return False
| isJust (LFS.resp_error tro) -> return False
| LFS.resp_oid tro /= sha256 || LFS.resp_size tro /= size ->
giveup "git-lfs server replied with other object than the one we requested"
| otherwise -> return True
retrieveCheap :: Key -> AssociatedFile -> FilePath -> Annex Bool
retrieveCheap _ _ _ = return False
remove :: TVar LFSHandle -> Remover
remove _h _key = do
warning "git-lfs does not support removing content"
return False