add git configs for clusters

CHANGELOG

@@ -1,6 +1,9 @@
 git-annex (10.20240532) UNRELEASED; urgency=medium
 
-  * Added updateproxy command and remote.name.annex-proxy configuration.
+  * Added git-annex updateproxy command and remote.name.annex-proxy
+    configuration.
+  * Added git-annex cluster command and remote.name.annex-cluster-node
+    and annex.cluster.name configuration.
   * Fix a bug where interrupting git-annex while it is updating the
     git-annex branch for an export could later lead to git fsck
     complaining about missing tree objects.

Types/Cluster.hs

@@ -34,8 +34,8 @@ newtype ClusterUUID = ClusterUUID UUID
 
 -- Smart constructor for a ClusterUUID.
 --
--- The input UUID can be a regular UUID (eg V4). It is converted to a valid
--- cluster uuid.
+-- The input UUID can be any regular UUID (eg V4). It is converted to a valid
+-- cluster UUID.
 mkClusterUUID :: UUID -> Maybe ClusterUUID
 mkClusterUUID (UUID b)
 	| B.length b > 14 = Just $ ClusterUUID $ UUID $

Types/GitConfig.hs

@@ -45,6 +45,7 @@ import Types.RefSpec
 import Types.RepoVersion
 import Types.StallDetection
 import Types.View
+import Types.Cluster
 import Config.DynamicConfig
 import Utility.HumanTime
 import Utility.Gpg (GpgCmd, mkGpgCmd)
@@ -155,6 +156,7 @@ data GitConfig = GitConfig
 	, annexPrivateRepos :: S.Set UUID
 	, annexAdviceNoSshCaching :: Bool
 	, annexViewUnsetDirectory :: ViewUnset
+	, annexClusters :: M.Map String ClusterUUID
 	}
 
 extractGitConfig :: ConfigSource -> Git.Repo -> GitConfig
@@ -283,6 +285,12 @@ extractGitConfig configsource r = GitConfig
 	, annexAdviceNoSshCaching = getbool (annexConfig "advicenosshcaching") True
 	, annexViewUnsetDirectory = ViewUnset $ fromMaybe "_" $
 		getmaybe (annexConfig "viewunsetdirectory")
+	, annexClusters = 
+		M.mapMaybe (mkClusterUUID . toUUID) $
+		M.mapKeys (drop (B.length clusterprefix) . fromConfigKey) $
+		M.filterWithKey
+			(\(ConfigKey k) _ -> clusterprefix `B.isPrefixOf` k)
+			(config r)
 	}
   where
 	getbool k d = fromMaybe d $ getmaybebool k
@@ -307,6 +315,8 @@ extractGitConfig configsource r = GitConfig
 	
 	hereuuid = maybe NoUUID toUUID $ getmaybe (annexConfig "uuid")
 
+	clusterprefix = annexConfigPrefix <> "cluster."
+
 {- Merge a GitConfig that comes from git-config with one containing
  - repository-global defaults. -}
 mergeGitConfig :: GitConfig -> GitConfig -> GitConfig
@@ -377,6 +387,7 @@ data RemoteGitConfig = RemoteGitConfig
 	, remoteAnnexMaxGitBundles :: Int
 	, remoteAnnexAllowEncryptedGitRepo :: Bool
 	, remoteAnnexProxy :: Bool
+	, remoteAnnexClusterNode :: Maybe [String]
 	, remoteUrl :: Maybe String
 
 	{- These settings are specific to particular types of remotes
@@ -462,6 +473,7 @@ extractRemoteGitConfig r remotename = do
 		, remoteAnnexAllowEncryptedGitRepo = 
 			getbool AllowEncryptedGitRepoField False
 		, remoteAnnexProxy = getbool ProxyField False
+		, remoteAnnexClusterNode = words <$> getmaybe ClusterNodeField
 		, remoteUrl = 
 			case Git.Config.getMaybe (remoteConfig remotename (remoteGitConfigKey UrlField)) r of
 				Just (ConfigValue b)
@@ -539,6 +551,7 @@ data RemoteGitConfigField
 	| MaxGitBundlesField
 	| AllowEncryptedGitRepoField
 	| ProxyField
+	| ClusterNodeField
 	| UrlField
 	| ShellField
 	| SshOptionsField
@@ -603,6 +616,7 @@ remoteGitConfigField = \case
 	AllowEncryptedGitRepoField -> inherited "allow-encrypted-gitrepo"
 	-- Allow proxy chains.
 	ProxyField -> inherited "proxy"
+	ClusterNodeField -> uninherited "cluster-node"
 	UrlField -> inherited "url"
 	ShellField -> inherited "shell"
 	SshOptionsField -> inherited "ssh-options"
@@ -654,9 +668,12 @@ dummyRemoteGitConfig = atomically $
 
 type UnqualifiedConfigKey = B.ByteString
 
+annexConfigPrefix :: B.ByteString
+annexConfigPrefix = "annex."
+
 {- A global annex setting in git config. -}
 annexConfig :: UnqualifiedConfigKey -> ConfigKey
-annexConfig key = ConfigKey ("annex." <> key)
+annexConfig key = ConfigKey (annexConfigPrefix <> key)
 
 class RemoteNameable r where
 	getRemoteName :: r -> RemoteName

doc/git-annex-preferred-content.mdwn

@@ -8,7 +8,7 @@ Each repository has a preferred content setting, which specifies content
 that the repository wants to have present. These settings can be configured
 using `git annex vicfg` or `git annex wanted`.
 They are used by the `--auto` option, by `git annex sync --content`,
-and by the git-annex assistant.
+by clusters, and by the git-annex assistant.
 
 While preferred content expresses a preference, it can be overridden
 by simply using `git annex drop`. On the other hand, required content

doc/git-annex-updateproxy.mdwn

@@ -22,7 +22,9 @@ git-annex branch. That tells other repositories about the proxy
 configuration.
 
 Suppose, for example, that remote "work" has had this command run in
-it. Then git-annex will know about an additional remote, "work-foo".
+it. Then after pulling from "work", git-annex will know about an
+additional remote, "work-foo". That remote will be accessed using "work" as
+a proxy. (This only works for remotes accessed over ssh.)
 
 # OPTIONS
 
@@ -31,6 +33,7 @@ it. Then git-annex will know about an additional remote, "work-foo".
 # SEE ALSO
 
 [[git-annex]](1)
+[[git-annex-cluster]](1)
 
 # AUTHOR
 

doc/git-annex.mdwn

@@ -1377,6 +1377,14 @@ repository, using [[git-annex-config]]. See its man page for a list.)
   set in global git configuration.
   For details, see <https://git-annex.branchable.com/tuning/>.
 
+* `annex.cluster.<name>`
+
+  [[git-annex-cluster]] sets this to the UUID of a cluster, to 
+  enable the local repository to act as a proxy to the cluster.
+
+  Note that cluster UUIDs are not the same as repository UUIDs,
+  and a repository UUID cannot be used here.
+
 # CONFIGURATION OF REMOTES
 
 Remotes are configured using these settings in `.git/config`.
@@ -1649,7 +1657,18 @@ Remotes are configured using these settings in `.git/config`.
 * `remote.<name>.annex-proxy`
 
   Set to "true" to make the local repository able to act as a proxy to this
-  remote. After configuring this, run [[git-annex-updateproxy](1) to store
+  remote. 
+
+  After configuring this, run [[git-annex-updateproxy](1) to store
+  the new configuration in the git-annex branch.
+
+* `remote.<name>.annex-cluster-node`
+
+  Set to the name of a cluster to make this remote be part of
+  the cluster. Names of multiple clusters can be separated by
+  whitespace to make a remote be part of more than one cluster.
+  
+  After configuring this, run [[git-annex-updatecluster](1) to store
   the new configuration in the git-annex branch.
 
 * `remote.<name>.annex-private`