list proxied remotes and cluster gateways in git-annex info

Wanted to also list a cluster's nodes when showing info for the cluster,
but that's hard because it needs getting the name of the proxying
remote, which is some prefix of the cluster's name, but if the names
contain dashes there's no good way to know which prefix it is.

Remote/Helper/Git.hs

@@ -1,6 +1,6 @@
 {- Utilities for git remotes.
  -
- - Copyright 2011-2014 Joey Hess <id@joeyh.name>
+ - Copyright 2011-2024 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -14,9 +14,13 @@ import Types.Availability
 import qualified Types.Remote as Remote
 import qualified Utility.RawFilePath as R
 import qualified Git.Config
+import Logs.Proxy
+import Types.Cluster
 
 import Data.Time.Clock.POSIX
 import System.PosixCompat.Files (modificationTime)
+import qualified Data.Map as M
+import qualified Data.Set as S
 
 repoCheap :: Git.Repo -> Bool
 repoCheap = not . Git.repoIsUrl
@@ -62,9 +66,26 @@ gitRepoInfo r = do
 		[] -> "never"
 		_ -> show $ posixSecondsToUTCTime $ realToFrac $ maximum mtimes
 	repo <- Remote.getRepo r
-	return
-		[ ("repository location", Git.repoLocation repo)
-		, ("proxied", Git.Config.boolConfig 
-			(isJust (remoteAnnexProxiedBy (Remote.gitconfig r))))
-		, ("last synced", lastsynctime)
+	let proxied = Git.Config.boolConfig $ isJust $
+		remoteAnnexProxiedBy (Remote.gitconfig r)
+	proxies <- getProxies
+	let proxying = S.toList $ fromMaybe mempty $
+		M.lookup (Remote.uuid r) proxies
+	let iscluster = isClusterUUID . proxyRemoteUUID
+	let proxyname p = Remote.name r ++ "-" ++ proxyRemoteName p
+	let proxynames = map proxyname $ filter (not . iscluster) proxying
+	let clusternames = map proxyname $ filter iscluster proxying
+	return $ catMaybes
+		[ Just ("repository location", Git.repoLocation repo)
+		, Just ("last synced", lastsynctime)
+		, Just ("proxied", proxied)
+		, if isClusterUUID (Remote.uuid r)
+			then Just ("cluster", Git.Config.boolConfig True)
+			else Nothing
+		, if null clusternames
+			then Nothing
+			else Just ("gateway to cluster", unwords clusternames)
+		, if null proxynames
+			then Nothing
+			else Just ("proxying", unwords proxynames)
 		]

doc/tips/clusters.mdwn

@@ -12,16 +12,21 @@ To use a cluster, your repository needs to have its gateway configured as a
 remote. Clusters can currently only be accessed via ssh. This gateway
 remote is added the same as any other git remote:
 
-    git remote add bigserver me@bigserver:annex
+    $ git remote add bigserver me@bigserver:annex
 
 The gateway publishes information about the cluster to the git-annex
 branch. So you may need to fetch from it to learn about the cluster:
 
-    git fetch bigserver
+    $ git fetch bigserver
 
 That will make available an additional remote for the cluster, eg
-"bigserver-mycluster", as well as some remotes for each node eg
-"bigserver-node1", "bigserver-node2", etc.
+"bigserver-mycluster", as well as some remotes for each node.
+
+	$ git annex info bigserver
+	...
+    gateway to cluster: bigserver-mycluster
+    proxying: bigserver-node1 bigserver-node2 bigserver-node3
+	...
 
 You can get files from the cluster without caring which node it comes
 from: