diff options
| author | Joey Hess <joeyh@joeyh.name> | 2015-09-25 09:24:16 -0400 |
|---|---|---|
| committer | Joey Hess <joeyh@joeyh.name> | 2015-09-25 09:24:16 -0400 |
| commit | 39a89b0827fca8a62bb80cf12a5abc75661bdaf9 (patch) | |
| tree | edc6bd924160a63778c2444729e33e52e5a4497a | |
| parent | b424c3da63bdb9897123b4481a02e087590bcc03 (diff) | |
Guard against power loss etc when building propellor, by updating the executable atomically.
| -rw-r--r-- | debian/changelog | 7 | ||||
| -rw-r--r-- | src/Propellor/Bootstrap.hs | 17 |
2 files changed, 22 insertions, 2 deletions
diff --git a/debian/changelog b/debian/changelog index 32eb7aea..41f1435c 100644 --- a/debian/changelog +++ b/debian/changelog @@ -1,3 +1,10 @@ +propellor (2.8.1) UNRELEASED; urgency=medium + + * Guard against power loss etc when building propellor, by updating + the executable atomically. + + -- Joey Hess <id@joeyh.name> Fri, 25 Sep 2015 09:21:41 -0400 + propellor (2.8.0) unstable; urgency=medium * Added Propellor.Property.Rsync. diff --git a/src/Propellor/Bootstrap.hs b/src/Propellor/Bootstrap.hs index 6812b4ab..b2cf5609 100644 --- a/src/Propellor/Bootstrap.hs +++ b/src/Propellor/Bootstrap.hs @@ -104,9 +104,22 @@ build = catchBoolIO $ do void $ cabal ["configure"] unlessM (cabal ["build"]) $ error "cabal build failed" - nukeFile "propellor" - createSymbolicLink "dist/build/propellor-config/propellor-config" "propellor" + -- For safety against eg power loss in the middle of the build, + -- make a copy of the binary, and move it into place atomically. + -- This ensures that the propellor symlink only ever points at + -- a binary that is fully built. Also, avoid ever removing + -- or breaking the symlink. + unlessM (boolSystem "cp" [Param cabalbuiltbin, Param (tmpfor safetycopy)]) $ + error "cp of binary failed" + rename (tmpfor safetycopy) safetycopy + createSymbolicLink safetycopy (tmpfor dest) + rename (tmpfor dest) dest return True + where + dest = "propellor" + cabalbuiltbin = "dist/build/propellor-config/propellor-config" + safetycopy = cabalbuiltbin ++ ".built" + tmpfor f = f ++ ".propellortmp" make :: FilePath -> [FilePath] -> IO Bool -> IO () make dest srcs builder = do |