webapp: Improve handling of remotes whose setup has stalled.

This includes recovery from the ssh-agent problem that led to many reporting
http://git-annex.branchable.com/bugs/Internal_Server_Error:_Unknown_UUID/
(Including fixing up .ssh/config to set IdentitiesOnly.)

Remotes that have no known uuid are now displayed in the webapp as
"unfinished". There's a link to check their status, and if the remote
has been set annex-ignore, a retry button can be used to unset that and
try again to set up the remote.

As this bug has shown, the process of adding a ssh remote has some failure
modes that are not really ideal. It would certianly be better if, when
setting up a ssh remote it would detect if it's failed to get the UUID,
and handle that in the remote setup process, rather than waiting until
later and handling it this way.

However, that's hard to do, particularly for local pairing, since the
PairListener runs as a background thread. The best it could do is pop up an
alert if there's a problem. This solution is not much different.

Also, this solution handles cases where the user has gotten their repo into
a mess manually and let's the assistant help with cleaning it up.

This commit was sponsored by Chia Shee Liang. Thanks!

Assistant/WebApp/RepoList.hs

@@ -13,6 +13,7 @@ import Assistant.WebApp.Common
 import Assistant.DaemonStatus
 import Assistant.WebApp.Notifications
 import Assistant.WebApp.Utility
+import Assistant.Ssh
 import qualified Annex
 import qualified Remote
 import qualified Types.Remote as Remote
@@ -22,6 +23,8 @@ import Logs.Remote
 import Logs.Trust
 import Logs.Group
 import Config
+import Git.Config
+import Assistant.Sync
 import Config.Cost
 import qualified Git
 #ifdef WITH_XMPP
@@ -177,8 +180,7 @@ repoList reposelector
 	  where
 		val iscloud r = Just (iscloud, (u, DisabledRepoActions $ r u))
 	list l = liftAnnex $ do
-		let l' = filter (\(u, _) -> u /= NoUUID) $
-			nubBy (\x y -> fst x == fst y) l
+		let l' = nubBy (\x y -> fst x == fst y) l
 		l'' <- zip
 			<$> Remote.prettyListUUIDs (map fst l')
 			<*> pure l'
@@ -223,3 +225,30 @@ reorderCosts remote rs = zip rs'' (insertCostAfter costs i)
 	rs' = filter (\r -> Remote.uuid r /= Remote.uuid remote) rs
 	costs = map Remote.cost rs'
 	rs'' = (\(x, y) -> x ++ [remote] ++ y) $ splitAt (i + 1) rs'
+
+{- Checks to see if any repositories with NoUUID have annex-ignore set.
+ - That could happen if there's a problem contacting a ssh remote
+ - soon after it was added. -}
+getCheckUnfinishedRepositoriesR :: Handler Html
+getCheckUnfinishedRepositoriesR = page "Unfinished repositories" (Just Configuration) $ do
+	stalled <- liftAnnex findStalled
+	$(widgetFile "configurators/checkunfinished")
+
+findStalled :: Annex [Remote]
+findStalled = filter isstalled <$> remoteListRefresh
+  where
+  	isstalled r = Remote.uuid r == NoUUID
+		&& remoteAnnexIgnore (Remote.gitconfig r)
+
+getRetryUnfinishedRepositoriesR :: Handler ()
+getRetryUnfinishedRepositoriesR = do
+	liftAssistant $ mapM_ unstall =<< liftAnnex findStalled
+	redirect DashboardR
+  where
+	unstall r = do
+		liftIO $ fixSshKeyPair
+		liftAnnex $ setConfig 
+			(remoteConfig (Remote.repo r) "ignore")
+			(boolConfig False)
+		syncRemote r
+		liftAnnex $ void remoteListRefresh

Assistant/WebApp/routes

@@ -32,6 +32,8 @@
 /config/repository/edit/new/cloud/#UUID EditNewCloudRepositoryR GET POST
 /config/repository/sync/disable/#UUID DisableSyncR GET
 /config/repository/sync/enable/#UUID EnableSyncR GET
+/config/repository/unfinished/check CheckUnfinishedRepositoriesR GET
+/config/repository/unfinished/retry RetryUnfinishedRepositoriesR GET
 
 /config/repository/add/drive AddDriveR GET POST
 /config/repository/add/drive/confirm/#RemovableDrive ConfirmAddDriveR GET