basic s3 remote start

But bucket name is not handled right; it needs to be globally unique.

Config.hs

@@ -31,11 +31,11 @@ setConfig k value = do
 getConfig :: Git.Repo -> ConfigKey -> String -> Annex String
 getConfig r key def = do
 	g <- Annex.gitRepo
-	let def' = Git.configGet g global def
-	return $ Git.configGet g local def'
-	where
-		local = "remote." ++ fromMaybe "" (Git.repoRemoteName r) ++ ".annex-" ++ key
-		global = "annex." ++ key
+	let def' = Git.configGet g ("annex." ++ key) def
+	return $ Git.configGet g (remoteConfig r key) def'
+
+remoteConfig :: Git.Repo -> ConfigKey -> String
+remoteConfig r key = "remote." ++ fromMaybe "" (Git.repoRemoteName r) ++ ".annex-" ++ key
 
 {- Calculates cost for a remote.
  -

Remote/S3.hs

@@ -7,9 +7,18 @@
 
 module Remote.S3 (generate) where
 
+import Network.AWS.AWSConnection
+import Network.AWS.S3Object
+import Network.AWS.S3Bucket
+import Network.AWS.AWSResult
+import qualified Data.ByteString.Lazy.Char8 as L
 import qualified Data.Map as Map
 import Data.String.Utils
-import Control.Monad (filterM, liftM)
+import Control.Monad (filterM, liftM, when)
+import Control.Monad.State (liftIO)
+import System.Environment
+import Data.Char
+import Messages
 
 import RemoteClass
 import Types
@@ -25,26 +34,13 @@ generate = do
 	todo <- filterM cachedUUID remotes
 	let ok = filter (`notElem` todo) remotes
 	
-	let actions = map genRemote ok ++
-		map (\r -> genRemote =<< tryS3ConfigRead r) todo
+	let actions = map (\r -> genRemote r =<< getUUID r) ok ++
+		map (\r -> genRemote r =<< getS3UUID r) todo
 	return (actions, map Git.repoDescribe todo)
 
 	where
 		cachedUUID r = liftM null $ getUUID r
 
-genRemote :: Git.Repo -> Annex (Remote Annex)
-genRemote r = do
-	return Remote {
-		uuid = error "TODO",
-		cost = error "TODO",
-		name = Git.repoDescribe r,
-		storeKey = error "TODO",
-		retrieveKeyFile = error "TODO",
-		removeKey = error "TODO",
-		hasKey = error "TODO",
-		hasKeyCheap = False
-	}
-
 {- S3 remotes have a remote.<name>.annex-s3-bucket config setting.
  - Git.Repo does not normally generate remotes for things that
  - have no configured url, so the Git.Repo objects have to be
@@ -57,5 +53,73 @@ findS3Remotes r = map construct remotepairs
 		construct (k,_) = Git.repoRemoteNameSet Git.repoFromUnknown k
 		s3remote k = startswith "remote." k && endswith ".annex-s3-bucket" k
 
-tryS3ConfigRead :: Git.Repo -> Annex Git.Repo
-tryS3ConfigRead r = error "TODO"
+genRemote :: Git.Repo -> UUID -> Annex (Remote Annex)
+genRemote r u = do
+	c <- remoteCost r
+	return Remote {
+		uuid = u,
+		cost = c,
+		name = Git.repoDescribe r,
+		storeKey = error "TODO",
+		retrieveKeyFile = error "TODO",
+		removeKey = error "TODO",
+		hasKey = error "TODO",
+		hasKeyCheap = False
+	}
+
+s3Connection :: Git.Repo -> Annex (Maybe AWSConnection)
+s3Connection r = do
+	host <- getS3Config r "s3-host" (Just defaultAmazonS3Host)
+	port <- getS3Config r "s3-port" (Just $ show defaultAmazonS3Port)
+	accesskey <- getS3Config r "s3-access-key-id" Nothing
+	secretkey <- getS3Config r "s3-secret-access-key" Nothing
+	case reads port of
+		[(p, _)] -> return $ Just $ AWSConnection host p accesskey secretkey
+		_ -> error $ "bad S3 port value: " ++ port
+
+withS3Connection :: Git.Repo -> Annex a -> ((AWSConnection, String) -> Annex a) -> Annex a
+withS3Connection r def a = do
+	c <- s3Connection r
+	case c of
+		Nothing -> def
+		Just c' -> do
+			b <- getConfig r "s3-bucket" ""
+			a (c', b)
+
+getS3Config :: Git.Repo -> String -> Maybe String-> Annex String
+getS3Config r s def = do
+	e <- liftIO $ catch (liftM Just $ getEnv envvar) (const $ return def)
+	v <- case e of
+		Nothing -> getConfig r s ""
+		Just d -> getConfig r s d
+	when (null v) $ error $ "set " ++ envvar ++ " or " ++ remoteConfig r s
+	return v
+	where
+		envvar = "ANNEX_" ++ map (\c -> if c == '-' then '_' else toUpper c) s
+
+{- The UUID of a S3 bucket is stored in a file "git-annex-uuid" in the
+ - bucket. Gets the UUID, or if there is none, sets a new UUID, possibly
+ - also creating the bucket. -}
+getS3UUID :: Git.Repo -> Annex UUID
+getS3UUID r = withS3Connection r disable $ \(c, b) -> do
+	res <- liftIO $
+		getObject c $ S3Object b uuidfile "" [] L.empty
+	case res of
+		Right o -> return $ L.unpack $ obj_data o
+		Left _ -> do
+			location <- getS3Config r "s3-datacenter" (Just "EU")
+			-- bucket may already exist, or not
+			_ <- liftIO $ createBucketIn c b location
+			u <- getUUID r
+			res' <- liftIO $ sendObject c $
+				S3Object b uuidfile "" [] $
+					L.pack u
+			case res' of
+				Right _ -> return u
+				Left e -> do
+					warning $ prettyReqError e
+					disable
+					
+	where
+		uuidfile = "git-annex-uuid"
+		disable = return "" -- empty uuid will disable this remote

debian/changelog

@@ -1,11 +1,12 @@
 git-annex (0.20110326) UNRELEASED; urgency=low
 
-  * annex.diskreserve can be given in arbitrary units (ie "0.5 gigabytes")
+  * Amazon is S3 now supported as a special type of remote.
   * Generalized remotes handling, laying groundwork for remotes that are
     not regular git remotes.
   * Provide a less expensive version of `git annex copy --to`, enabled
     via --fast. This assumes that location tracking information is correct,
     rather than contacting the remote for every file.
+  * annex.diskreserve can be given in arbitrary units (ie "0.5 gigabytes")
 
  -- Joey Hess <joeyh@debian.org>  Sat, 26 Mar 2011 14:36:16 -0400