module Propellor.Property.Obnam where import Propellor import qualified Propellor.Property.Apt as Apt import qualified Propellor.Property.Cron as Cron import Utility.SafeCommand import Data.List installed :: Property installed = Apt.installed ["obnam"] type ObnamParam = String -- | An obnam repository can be used by multiple clients. Obnam uses -- locking to allow only one client to write at a time. Since stale lock -- files can prevent backups from happening, it's more robust, if you know -- a repository has only one client, to force the lock before starting a -- backup. Using OnlyClient allows propellor to do so when running obnam. data NumClients = OnlyClient | MultipleClients deriving (Eq) -- | Installs a cron job that causes a given directory to be backed -- up, by running obnam with some parameters. -- -- If the directory does not exist, or exists but is completely empty, -- this Property will immediately restore it from an existing backup. -- -- So, this property can be used to deploy a directory of content -- to a host, while also ensuring any changes made to it get backed up. -- And since Obnam encrypts, just make this property depend on a gpg -- key, and tell obnam to use the key, and your data will be backed -- up securely. For example: -- -- > & Obnam.backup "/srv/git" "33 3 * * *" -- > [ "--repository=sftp://2318@usw-s002.rsync.net/~/mygitrepos.obnam" -- > , "--encrypt-with=1B169BE1" -- > ] Obnam.OnlyClient -- > `requires` Gpg.keyImported "1B169BE1" "root" -- > `requires` Ssh.keyImported SshRsa "root" -- -- How awesome is that? backup :: FilePath -> Cron.CronTimes -> [ObnamParam] -> NumClients -> Property backup dir crontimes params numclients = cronjob `describe` desc `requires` restored dir params where desc = dir ++ " backed up by obnam" cronjob = Cron.niceJob ("obnam_backup" ++ dir) crontimes "root" "/" $ intercalate ";" $ catMaybes [ if numclients == OnlyClient then Just $ unwords $ [ "obnam" , "force-lock" ] ++ map shellEscape params else Nothing , Just $ unwords $ [ "obnam" , "backup" , shellEscape dir ] ++ map shellEscape params ] -- | Restores a directory from an obnam backup. -- -- Only does anything if the directory does not exist, or exists, -- but is completely empty. -- -- The restore is performed atomically; restoring to a temp directory -- and then moving it to the directory. restored :: FilePath -> [ObnamParam] -> Property restored dir params = Property (dir ++ " restored by obnam") go `requires` installed where go = ifM (liftIO needsRestore) ( liftIO restore , noChange ) needsRestore = null <$> catchDefaultIO [] (dirContents dir) restore = withTmpDirIn (takeDirectory dir) "obnam-restore" $ \tmpdir -> do ok <- boolSystem "obnam" $ [ Param "restore" , Param "--to" , Param tmpdir ] ++ map Param params let restoreddir = tmpdir ++ "/" ++ dir ifM (pure ok <&&> doesDirectoryExist restoreddir) ( do void $ tryIO $ removeDirectory dir renameDirectory restoreddir dir return MadeChange , return FailedChange )