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authorJoey Hess2017-06-18 18:24:05 -0400
committerJoey Hess2017-06-18 18:24:05 -0400
commit01fc1375cece096ab2dec480b843ecdbc4f0d94e (patch)
treefb620f98f3e891eac092d31ed5ab43a8975bd3a0 /src
parent9b457ae66d5c5143f5896156cc4af8d5a0bc0ddc (diff)
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.
Diffstat (limited to 'src')
-rw-r--r--src/Propellor/Spin.hs102
1 files changed, 60 insertions, 42 deletions
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