use a remote server

bup-backup.hs

@@ -1,7 +1,7 @@
 #!/usr/bin/env nix-script
 #!>haskell
 #! shell   | bup git
-#! env     | BUP_DIR
+#! env     | BUP_DIR BUP_SRV
 #! haskell | shell-conduit filepath
 
 import Data.List                   (intersperse)
@@ -9,6 +9,7 @@ import Data.Conduit.Shell
 import Data.Conduit.Shell.Segments (strings)
 import Data.Conduit.Shell.Variadic (variadicProcess)
 import System.FilePath
+import System.Environment (lookupEnv)
 
 
 -- | regexs for excluded files
@@ -21,25 +22,28 @@ excluded = intersperse "--exclude-rx"
 
 
 main :: IO ()
-main = run $ mapM_ backup =<< strings (bup "ls")
+main = do
+  var <- lookupEnv "BUP_SRV"
+  case var of
+    Nothing -> run (echo "set the BUP_SRV variable to hostname:path")
+    Just server -> run $
+      mapM_ (backup server) =<< strings (bup "ls" "-r" server) 
 
 
--- | Finds the path of a backup
-findPath :: String -> Segment FilePath
-findPath path = do
-  files <- strings (bup "ls" "-A" path)
-  if length files == 1
-    then findPath (path </> head files)
-    else return $ "/" </> final path
+findPath :: String -> String -> Segment FilePath
+findPath server path = do
+  files <- strings (bup "ls" "-A" "-r" server path)
+  if length files /= 1
+    then return ("/" </> final path)
+    else findPath server (path </> head files)
   where final = concat . drop 2 . splitPath
 
 
--- | Runs the backup
-backup :: String -> Segment ()
-backup name = do
-  path <- findPath (name </> "latest")
+backup :: String -> String -> Segment ()
+backup server name = do
+  path <- findPath server (name </> "latest")
   proc "bup" ("index" : path : "--exclude-rx" : excluded)
-  bup "save" "-n" name path
+  bup "save" "-r" server "-n" name path
 
 
 -- | Fix for missing execs on NixOS