{-# LANGUAGE FlexibleInstances, FlexibleContexts #-} module Propellor.Property.File where import Propellor.Base import qualified Data.ByteString.Lazy as L import Data.List (isInfixOf, isPrefixOf) import System.Posix.Files import System.Exit import Data.Char type Line = String -- | Replaces all the content of a file. hasContent :: FilePath -> [Line] -> Property UnixLike f `hasContent` newcontent = fileProperty ("replace " ++ f) (\_oldcontent -> newcontent) f -- | Ensures that a line is present in a file, adding it to the end if not. -- -- For example: -- -- > & "/etc/default/daemon.conf" `File.containsLine` ("cachesize = " ++ val 1024) -- -- The above example uses `val` to serialize a `ConfigurableValue` containsLine :: FilePath -> Line -> Property UnixLike f `containsLine` l = f `containsLines` [l] -- | Ensures that a list of lines are present in a file, adding any that are not -- to the end of the file. -- -- Note that this property does not guarantee that the lines will appear -- consecutively, nor in the order specified. If you need either of these, use -- 'File.containsBlock'. containsLines :: FilePath -> [Line] -> Property UnixLike f `containsLines` ls = fileProperty (f ++ " contains:" ++ show ls) go f where go content = content ++ filter (`notElem` content) ls -- | Ensures that a block of consecutive lines is present in a file, adding it -- to the end if not. Revert to ensure that the block is not present (though -- the lines it contains could be present, non-consecutively). containsBlock :: FilePath -> [Line] -> RevertableProperty UnixLike UnixLike f `containsBlock` ls = fileProperty (f ++ " contains block:" ++ show ls) add f fileProperty (f ++ " lacks block:" ++ show ls) remove f where add content | ls `isInfixOf` content = content | otherwise = content ++ ls remove [] = [] remove content@(x:xs) | ls `isPrefixOf` content = remove (drop (length ls) content) | otherwise = x : remove xs -- | Ensures that a line is not present in a file. -- Note that the file is ensured to exist, so if it doesn't, an empty -- file will be written. lacksLine :: FilePath -> Line -> Property UnixLike f `lacksLine` l = fileProperty (f ++ " remove: " ++ l) (filter (/= l)) f lacksLines :: FilePath -> [Line] -> Property UnixLike f `lacksLines` ls = fileProperty (f ++ " remove: " ++ show [ls]) (filter (`notElem` ls)) f -- | Replaces all the content of a file, ensuring that its modes do not -- allow it to be read or written by anyone other than the current user hasContentProtected :: FilePath -> [Line] -> Property UnixLike f `hasContentProtected` newcontent = fileProperty' ProtectedWrite ("replace " ++ f) (\_oldcontent -> newcontent) f -- | Ensures a file has contents that comes from PrivData. -- -- The file's permissions are preserved if the file already existed. -- Otherwise, they're set to 600. hasPrivContent :: IsContext c => FilePath -> c -> Property (HasInfo + UnixLike) hasPrivContent f = hasPrivContentFrom (PrivDataSourceFile (PrivFile f) f) f -- | Like hasPrivContent, but allows specifying a source -- for PrivData, rather than using `PrivDataSourceFile`. hasPrivContentFrom :: (IsContext c, IsPrivDataSource s) => s -> FilePath -> c -> Property (HasInfo + UnixLike) hasPrivContentFrom = hasPrivContent' ProtectedWrite -- | Leaves the file at its default or current mode, -- allowing "private" data to be read. -- -- Use with caution! hasPrivContentExposed :: IsContext c => FilePath -> c -> Property (HasInfo + UnixLike) hasPrivContentExposed f = hasPrivContentExposedFrom (PrivDataSourceFile (PrivFile f) f) f hasPrivContentExposedFrom :: (IsContext c, IsPrivDataSource s) => s -> FilePath -> c -> Property (HasInfo + UnixLike) hasPrivContentExposedFrom = hasPrivContent' NormalWrite hasPrivContent' :: (IsContext c, IsPrivDataSource s) => FileWriteMode -> s -> FilePath -> c -> Property (HasInfo + UnixLike) hasPrivContent' writemode source f context = withPrivData source context $ \getcontent -> property' desc $ \o -> getcontent $ \privcontent -> ensureProperty o $ fileProperty' writemode desc (\_oldcontent -> privDataByteString privcontent) f where desc = "privcontent " ++ f -- | Replaces the content of a file with the transformed content of another file basedOn :: FilePath -> (FilePath, [Line] -> [Line]) -> Property UnixLike f `basedOn` (src, a) = property' desc $ \o -> do tmpl <- liftIO $ readFile src ensureProperty o $ fileProperty desc (\_ -> a $ lines $ tmpl) f where desc = f ++ " is based on " ++ src -- | Removes a file. Does not remove symlinks or non-plain-files. notPresent :: FilePath -> Property UnixLike notPresent f = check (doesFileExist f) $ property (f ++ " not present") $ makeChange $ nukeFile f -- | Ensures a directory exists. dirExists :: FilePath -> Property UnixLike dirExists d = check (not <$> doesDirectoryExist d) $ property (d ++ " exists") $ makeChange $ createDirectoryIfMissing True d -- | The location that a symbolic link points to. newtype LinkTarget = LinkTarget FilePath -- | Creates or atomically updates a symbolic link. -- -- Revert to ensure no symlink is present. -- -- Does not overwrite or delete regular files or directories. isSymlinkedTo :: FilePath -> LinkTarget -> RevertableProperty UnixLike UnixLike link `isSymlinkedTo` (LinkTarget target) = linked notLinked where linked = property (link ++ " is symlinked to " ++ target) $ go =<< getLinkStatus go (Right stat) = if isSymbolicLink stat then checkLink else nonSymlinkExists go (Left _) = makeChange $ createSymbolicLink target link notLinked = property (link ++ "does not exist as a symlink") $ stop =<< getLinkStatus stop (Right stat) = if isSymbolicLink stat then makeChange $ nukeFile link else nonSymlinkExists stop (Left _) = noChange nonSymlinkExists = do warningMessage $ link ++ " exists and is not a symlink" return FailedChange checkLink = do target' <- liftIO $ readSymbolicLink link if target == target' then noChange else makeChange updateLink updateLink = createSymbolicLink target `viaStableTmp` link getLinkStatus = liftIO $ tryIO $ getSymbolicLinkStatus link -- | Ensures that a file is a copy of another (regular) file. isCopyOf :: FilePath -> FilePath -> Property UnixLike f `isCopyOf` src = property desc $ go =<< (liftIO $ tryIO $ getFileStatus src) where desc = f ++ " is copy of " ++ src go (Right stat) = if isRegularFile stat then ifM (liftIO $ doesFileExist f) ( gocmp =<< (liftIO $ cmp) , doit ) else warningMessage (src ++ " is not a regular file") >> return FailedChange go (Left e) = warningMessage (show e) >> return FailedChange cmp = safeSystem "cmp" [Param "-s", Param "--", File f, File src] gocmp ExitSuccess = noChange gocmp (ExitFailure 1) = doit gocmp _ = warningMessage "cmp failed" >> return FailedChange doit = makeChange $ copy `viaStableTmp` f copy dest = unlessM (runcp dest) $ errorMessage "cp failed" runcp dest = boolSystem "cp" [Param "--preserve=all", Param "--", File src, File dest] -- | Ensures that a file/dir has the specified owner and group. ownerGroup :: FilePath -> User -> Group -> Property UnixLike ownerGroup f (User owner) (Group group) = p `describe` (f ++ " owner " ++ og) where p = cmdProperty "chown" [og, f] `changesFile` f og = owner ++ ":" ++ group -- | Given a base directory, and a relative path under that -- directory, applies a property to each component of the path in turn, -- starting with the base directory. -- -- For example, to make a file owned by a user, making sure their home -- directory and the subdirectories to it are also owned by them: -- -- > "/home/user/program/file" `hasContent` ["foo"] -- > `before` applyPath "/home/user" ".config/program/file" -- > (\f -> ownerGroup f (User "user") (Group "user")) applyPath :: Monoid (Property metatypes) => FilePath -> FilePath -> (FilePath -> Property metatypes) -> Property metatypes applyPath basedir relpath mkp = mconcat $ map mkp (scanl () basedir (splitPath relpath)) -- | Ensures that a file/dir has the specfied mode. mode :: FilePath -> FileMode -> Property UnixLike mode f v = p `changesFile` f where p = property (f ++ " mode " ++ show v) $ do liftIO $ modifyFileMode f (const v) return NoChange class FileContent c where emptyFileContent :: c readFileContent :: FilePath -> IO c writeFileContent :: FileWriteMode -> FilePath -> c -> IO () data FileWriteMode = NormalWrite | ProtectedWrite instance FileContent [Line] where emptyFileContent = [] readFileContent f = lines <$> readFile f writeFileContent NormalWrite f ls = writeFile f (unlines ls) writeFileContent ProtectedWrite f ls = writeFileProtected f (unlines ls) instance FileContent L.ByteString where emptyFileContent = L.empty readFileContent = L.readFile writeFileContent NormalWrite f c = L.writeFile f c writeFileContent ProtectedWrite f c = writeFileProtected' f (`L.hPutStr` c) -- | A property that applies a pure function to the content of a file. fileProperty :: (FileContent c, Eq c) => Desc -> (c -> c) -> FilePath -> Property UnixLike fileProperty = fileProperty' NormalWrite fileProperty' :: (FileContent c, Eq c) => FileWriteMode -> Desc -> (c -> c) -> FilePath -> Property UnixLike fileProperty' writemode desc a f = property desc $ go =<< liftIO (doesFileExist f) where go True = do old <- liftIO $ readFileContent f let new = a old if old == new then noChange else makeChange $ updatefile new `viaStableTmp` f go False = makeChange $ writer f (a emptyFileContent) -- Replicate the original file's owner and mode. updatefile content dest = do writer dest content s <- getFileStatus f setFileMode dest (fileMode s) setOwnerAndGroup dest (fileOwner s) (fileGroup s) writer = writeFileContent writemode -- | A temp file to use when writing new content for a file. -- -- This is a stable name so it can be removed idempotently. -- -- It ends with "~" so that programs that read many config files from a -- directory will treat it as an editor backup file, and not read it. stableTmpFor :: FilePath -> FilePath stableTmpFor f = f ++ ".propellor-new~" -- | Creates/updates a file atomically, running the action to create the -- stable tmp file, and then renaming it into place. viaStableTmp :: (MonadMask m, MonadIO m) => (FilePath -> m ()) -> FilePath -> m () viaStableTmp a f = bracketIO setup cleanup go where setup = do createDirectoryIfMissing True (takeDirectory f) let tmpfile = stableTmpFor f nukeFile tmpfile return tmpfile cleanup tmpfile = tryIO $ removeFile tmpfile go tmpfile = do a tmpfile liftIO $ rename tmpfile f -- | Generates a base configuration file name from a String, which -- can be put in a configuration directory, such as -- -- -- The generated file name is limited to using ASCII alphanumerics, -- \'_\' and \'.\' , so that programs that only accept a limited set of -- characters will accept it. Any other characters will be encoded -- in escaped form. -- -- Some file extensions, such as ".old" may be filtered out by -- programs that use configuration directories. To avoid such problems, -- it's a good idea to add an static prefix and extension to the -- result of this function. For example: -- -- > aptConf foo = "/etc/apt/apt.conf.d" "propellor_" ++ configFileName foo <.> ".conf" configFileName :: String -> FilePath configFileName = concatMap escape where escape c | isAscii c && isAlphaNum c = [c] | c == '.' = [c] | otherwise = '_' : show (ord c) -- | Applies configFileName to any value that can be shown. showConfigFileName :: Show v => v -> FilePath showConfigFileName = configFileName . show -- | Inverse of showConfigFileName. readConfigFileName :: Read v => FilePath -> Maybe v readConfigFileName = readish . unescape where unescape [] = [] unescape ('_':cs) = case break (not . isDigit) cs of ([], _) -> '_' : unescape cs (ns, cs') -> case readish ns of Nothing -> '_' : ns ++ unescape cs' Just n -> chr n : unescape cs' unescape (c:cs) = c : unescape cs data Overwrite = OverwriteExisting | PreserveExisting -- | When passed PreserveExisting, only ensures the property when the file -- does not exist. checkOverwrite :: Overwrite -> FilePath -> (FilePath -> Property i) -> Property i checkOverwrite OverwriteExisting f mkp = mkp f checkOverwrite PreserveExisting f mkp = check (not <$> doesFileExist f) (mkp f)