From 01fc1375cece096ab2dec480b843ecdbc4f0d94e Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Sun, 18 Jun 2017 18:24:05 -0400 Subject: Fix bug that sometimes made --spin fail with "fatal: Couldn't find remote ref HEAD" Tricky stdin buffering problem. An easier fix would have been: hSetBuffering stdin NoBuffering But that approach is less robust; even with NoBuffering, anything that uses hLookAhead causes 1 byte of buffering. And, any reads from stdin before hSetBuffering would still cause the problem. Instead, I used a bigger hammer that will always work. It involves a bit more CPU work, but this is data that is already being fed through ssh; copying it one more time won't cause a measurable performance impact. This commit was sponsored by Jack Hill on Patreon. --- src/Propellor/Spin.hs | 102 +++++++++++++++++++++++++++++--------------------- 1 file changed, 60 insertions(+), 42 deletions(-) (limited to 'src') diff --git a/src/Propellor/Spin.hs b/src/Propellor/Spin.hs index d0ce4d03..cc5fa0e8 100644 --- a/src/Propellor/Spin.hs +++ b/src/Propellor/Spin.hs @@ -186,26 +186,8 @@ update forhost = do writeFileProtected privfile whenM hasGitRepo $ - req NeedGitPush gitPushMarker $ \_ -> do - hin <- dup stdInput - hout <- dup stdOutput - hClose stdin - hClose stdout - -- Not using git pull because git 2.5.0 badly - -- broke its option parser. - unlessM (boolSystemNonConcurrent "git" (pullparams hin hout)) $ - errorMessage "git fetch from client failed" - unlessM (boolSystemNonConcurrent "git" [Param "merge", Param "FETCH_HEAD"]) $ - errorMessage "git merge from client failed" + gitPullFromUpdateServer where - pullparams hin hout = - [ Param "fetch" - , Param "--progress" - , Param "--upload-pack" - , Param $ "./propellor --gitpush " ++ show hin ++ " " ++ show hout - , Param "." - ] - -- When --spin --relay is run, get a privdata file -- to be relayed to the target host. privfile = maybe privDataLocal privDataRelay forhost @@ -336,29 +318,6 @@ sendPrecompiled hn = void $ actionMessage "Uploading locally compiled propellor , "rm -f " ++ remotetarball ] --- Shim for git push over the propellor ssh channel. --- Reads from stdin and sends it to hout; --- reads from hin and sends it to stdout. -gitPushHelper :: Fd -> Fd -> IO () -gitPushHelper hin hout = void $ fromstdin `concurrently` tostdout - where - fromstdin = do - h <- fdToHandle hout - connect stdin h - tostdout = do - h <- fdToHandle hin - connect h stdout - connect fromh toh = do - b <- B.hGetSome fromh 40960 - if B.null b - then do - hClose fromh - hClose toh - else do - B.hPut toh b - hFlush toh - connect fromh toh - mergeSpin :: IO () mergeSpin = do branch <- getCurrentBranch @@ -386,3 +345,62 @@ findLastNonSpinCommit = do spinCommitMessage :: String spinCommitMessage = "propellor spin" + +-- Stdin and stdout are connected to the updateServer over ssh. +-- Request that it run git upload-pack, and connect that up to a git fetch +-- to receive the data. +gitPullFromUpdateServer :: IO () +gitPullFromUpdateServer = req NeedGitPush gitPushMarker $ \_ -> do + -- IO involving stdin can cause data to be buffered in the Handle + -- (even when it's set NoBuffering), but we need to pass a FD to + -- git fetch containing all of stdin after the gitPushMarker, + -- including any that has been buffered. + -- + -- To do so, create a pipe, and forward stdin, including any + -- buffered part, through it. + (pread, pwrite) <- System.Posix.IO.createPipe + hwrite <- fdToHandle pwrite + _ <- async $ stdin *>* hwrite + let hin = pread + hout <- dup stdOutput + hClose stdout + -- Not using git pull because git 2.5.0 badly + -- broke its option parser. + unlessM (boolSystemNonConcurrent "git" (fetchparams hin hout)) $ + errorMessage "git fetch from client failed" + unlessM (boolSystemNonConcurrent "git" [Param "merge", Param "FETCH_HEAD"]) $ + errorMessage "git merge from client failed" + where + fetchparams hin hout = + [ Param "fetch" + , Param "--progress" + , Param "--upload-pack" + , Param $ "./propellor --gitpush " ++ show hin ++ " " ++ show hout + , Param "." + ] + +-- Shim for git push over the propellor ssh channel. +-- Reads from stdin and sends it to hout; +-- reads from hin and sends it to stdout. +gitPushHelper :: Fd -> Fd -> IO () +gitPushHelper hin hout = void $ fromstdin `concurrently` tostdout + where + fromstdin = do + h <- fdToHandle hout + stdin *>* h + tostdout = do + h <- fdToHandle hin + h *>* stdout + +-- Forward data from one handle to another. +(*>*) :: Handle -> Handle -> IO () +fromh *>* toh = do + b <- B.hGetSome fromh 40960 + if B.null b + then do + hClose fromh + hClose toh + else do + B.hPut toh b + hFlush toh + fromh *>* toh -- cgit v1.2.3