git-annex/RemoteDaemon/Transport/Ssh.hs
Joey Hess 29e73f76ef
Added remote.<name>.annex-push and remote.<name>.annex-pull
The former can be useful to make remotes that don't get fully synced with
local changes, which comes up in a lot of situations.

The latter was mostly added for symmetry, but could be useful (though less
likely to be).

Implementing `remote.<name>.annex-pull` was a bit tricky, as there's no one
place where git-annex pulls/fetches from remotes. I audited all
instances of "fetch" and "pull". A few cases were left not checking this
config:

* Git.Repair can try to pull missing refs from a remote, and if the local
  repo is corrupted, that seems a reasonable thing to do even though
  the config would normally prevent it.
* Assistant.WebApp.Gpg and Remote.Gcrypt and Remote.Git do fetches
  as part of the setup process of a remote. The config would probably not
  be set then, and having the setup fail seems worse than honoring it if it
  is already set.

I have not prevented all the code that does a "merge" from merging branches
from remotes with remote.<name>.annex-pull=false. That could perhaps
be done, but it would need a way to map from branch name to remote name,
and the way refspecs work makes that hard to get really correct. So if the
user fetches manually, the git-annex branch will get merged, for example.
Anther way of looking at/justifying this is that the setting is called
"annex-pull", not "annex-merge".

This commit was supported by the NSF-funded DataLad project.
2017-04-05 13:22:35 -04:00

106 lines
3.2 KiB
Haskell

{- git-remote-daemon, git-annex-shell over ssh transport
-
- Copyright 2014 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module RemoteDaemon.Transport.Ssh (transport, transportUsingCmd) where
import Annex.Common
import Annex.Ssh
import RemoteDaemon.Types
import RemoteDaemon.Common
import Remote.Helper.Ssh
import qualified RemoteDaemon.Transport.Ssh.Types as SshRemote
import Utility.SimpleProtocol
import qualified Git
import Git.Command
import Annex.ChangedRefs
import Control.Concurrent.STM
import Control.Concurrent.Async
transport :: Transport
transport rr@(RemoteRepo r _) url h ichan ochan = do
v <- liftAnnex h $ git_annex_shell ConsumeStdin r "notifychanges" [] []
case v of
Nothing -> noop
Just (cmd, params) -> transportUsingCmd cmd params rr url h ichan ochan
transportUsingCmd :: FilePath -> [CommandParam] -> Transport
transportUsingCmd cmd params rr@(RemoteRepo r gc) url h@(TransportHandle (LocalRepo g) s) ichan ochan = do
-- enable ssh connection caching wherever inLocalRepo is called
g' <- liftAnnex h $ sshOptionsTo r gc g
let transporthandle = TransportHandle (LocalRepo g') s
transportUsingCmd' cmd params rr url transporthandle ichan ochan
transportUsingCmd' :: FilePath -> [CommandParam] -> Transport
transportUsingCmd' cmd params (RemoteRepo r gc) url transporthandle ichan ochan =
robustConnection 1 $ do
(Just toh, Just fromh, Just errh, pid) <-
createProcess (proc cmd (toCommand params))
{ std_in = CreatePipe
, std_out = CreatePipe
, std_err = CreatePipe
}
-- Run all threads until one finishes and get the status
-- of the first to finish. Cancel the rest.
status <- catchDefaultIO (Right ConnectionClosed) $
handlestderr errh
`race` handlestdout fromh
`race` handlecontrol
send (DISCONNECTED url)
hClose toh
hClose fromh
void $ waitForProcess pid
return $ either (either id id) id status
where
send msg = atomically $ writeTChan ochan msg
fetch = do
send (SYNCING url)
ok <- inLocalRepo transporthandle $
runBool [Param "fetch", Param $ Git.repoDescribe r]
send (DONESYNCING url ok)
handlestdout fromh = do
ml <- getProtocolLine fromh
case parseMessage =<< ml of
Just SshRemote.READY -> do
send (CONNECTED url)
handlestdout fromh
Just (SshRemote.CHANGED (ChangedRefs shas)) -> do
whenM (checkShouldFetch gc transporthandle shas) $
fetch
handlestdout fromh
-- avoid reconnect on protocol error
Nothing -> return ConnectionStopping
handlecontrol = do
msg <- atomically $ readTChan ichan
case msg of
STOP -> return ConnectionStopping
LOSTNET -> return ConnectionStopping
_ -> handlecontrol
-- Old versions of git-annex-shell that do not support
-- the notifychanges command will exit with a not very useful
-- error message. Detect that error, and avoid reconnecting.
-- Propigate all stderr.
handlestderr errh = do
s <- hGetSomeString errh 1024
hPutStr stderr s
hFlush stderr
if "git-annex-shell: git-shell failed" `isInfixOf` s
then do
send $ WARNING url $ unwords
[ "Remote", Git.repoDescribe r
, "needs its git-annex upgraded"
, "to 5.20140405 or newer"
]
return ConnectionStopping
else handlestderr errh