remotedaemon: Fork to background by default. Added --foreground switch to enable old behavior.

Groundwork for tor hidden services, which the remotedaemon will serve.

Assistant/Threads/RemoteControl.hs

@@ -30,7 +30,7 @@ remoteControlThread :: NamedThread
 remoteControlThread = namedThread "RemoteControl" $ do
 	program <- liftIO programPath
 	(cmd, params) <- liftIO $ toBatchCommand
-		(program, [Param "remotedaemon"])
+		(program, [Param "remotedaemon", Param "--foreground"])
 	let p = proc cmd (toCommand params)
 	(Just toh, Just fromh, _, pid) <- liftIO $ createProcess p
 		{ std_in = CreatePipe

CHANGELOG

@@ -1,3 +1,10 @@
+git-annex (6.20161119) UNRELEASED; urgency=medium
+
+  * remotedaemon: Fork to background by default. Added --foreground switch
+    to enable old behavior.
+
+ -- Joey Hess <id@joeyh.name>  Sun, 20 Nov 2016 14:10:15 -0400
+
 git-annex (6.20161118) unstable; urgency=medium
 
   * git-annex.cabal: Loosen bounds on persistent to allow 2.5, which

Command/EnableTor.hs

@@ -14,7 +14,7 @@ import Utility.Tor
 -- git-annex, as that would create root-owned files.
 cmd :: Command
 cmd = noCommit $ dontCheck repoExists $
-	command "enable-tor" SectionPlumbing ""
+	command "enable-tor" SectionSetup ""
 		"userid uuid" (withParams seek)
 
 seek :: CmdParams -> CommandSeek

Command/RemoteDaemon.hs

@@ -1,25 +1,32 @@
 {- git-annex command
  -
- - Copyright 2014 Joey Hess <id@joeyh.name>
+ - Copyright 2014-2016 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
+{-# LANGUAGE CPP #-}
+
 module Command.RemoteDaemon where
 
 import Command
 import RemoteDaemon.Core
+import Utility.Daemon
 
 cmd :: Command
-cmd = noCommit $ 
-	command "remotedaemon" SectionPlumbing
-		"detects when remotes have changed, and fetches from them"
-		paramNothing (withParams seek)
+cmd = noCommit $ dontCheck repoExists $
+	command "remotedaemon" SectionMaintenance
+		"persistent communication with remotes"
+		paramNothing (run <$$> const parseDaemonOptions)
 
-seek :: CmdParams -> CommandSeek
-seek = withNothing start
-
-start :: CommandStart
-start = do
-	liftIO runForeground
-	stop
+run :: DaemonOptions -> CommandSeek
+run o
+	| stopDaemonOption o = error "--stop not implemented for remotedaemon"
+	| foregroundDaemonOption o = liftIO runInteractive
+	| otherwise = do
+#ifndef mingw32_HOST_OS
+		nullfd <- liftIO $ openFd "/dev/null" ReadOnly Nothing defaultFileFlags
+		liftIO $ daemonize nullfd Nothing False runNonInteractive
+#else
+		liftIO $ foreground Nothing runNonInteractive	
+#endif

RemoteDaemon/Core.hs

@@ -1,11 +1,11 @@
 {- git-remote-daemon core
  -
- - Copyright 2014 Joey Hess <id@joeyh.name>
+ - Copyright 2014-2016 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
-module RemoteDaemon.Core (runForeground) where
+module RemoteDaemon.Core (runInteractive, runNonInteractive) where
 
 import qualified Annex
 import Common
@@ -17,6 +17,7 @@ import qualified Git
 import qualified Git.Types as Git
 import qualified Git.CurrentRepo
 import Utility.SimpleProtocol
+import Utility.ThreadScheduler
 import Config
 import Annex.Ssh
 
@@ -26,8 +27,8 @@ import Control.Concurrent.STM
 import Network.URI
 import qualified Data.Map as M
 
-runForeground :: IO ()
-runForeground = do
+runInteractive :: IO ()
+runInteractive = do
 	(readh, writeh) <- dupIoHandles
 	ichan <- newTChanIO :: IO (TChan Consumed)
 	ochan <- newTChanIO :: IO (TChan Emitted)
@@ -44,8 +45,21 @@ runForeground = do
 	let controller = runController ichan ochan
 	
 	-- If any thread fails, the rest will be killed.
-	void $ tryIO $
-		reader `concurrently` writer `concurrently` controller
+	void $ tryIO $ reader `concurrently` writer `concurrently` controller
+
+runNonInteractive :: IO ()
+runNonInteractive = do
+	ichan <- newTChanIO :: IO (TChan Consumed)
+	ochan <- newTChanIO :: IO (TChan Emitted)
+	
+	let reader = forever $ do
+		threadDelaySeconds (Seconds (60*60))
+		atomically $ writeTChan ichan RELOAD
+	let writer = forever $
+		void $ atomically $ readTChan ochan
+	let controller = runController ichan ochan
+	
+	void $ tryIO $ reader `concurrently` writer `concurrently` controller
 
 type RemoteMap = M.Map Git.Repo (IO (), TChan Consumed)
 

doc/git-annex-enable-tor.mdwn

@@ -14,10 +14,15 @@ It outputs to stdout a line of the form "address.onion:onionport socketfile"
 
 This command has to be run by root, since it modifies `/etc/tor/torrc`.
 
+After this command is run, `git annex remotedaemon` can be run to serve the
+hidden service.
+
 # SEE ALSO
 
 [[git-annex]](1)
 
+[[git-annex-remotedaemon]](1)
+
 # AUTHOR
 
 Joey Hess <id@joeyh.name>

doc/git-annex-remotedaemon.mdwn

@@ -1,6 +1,6 @@
 # NAME
 
-git-annex remotedaemon - detects when remotes have changed, and fetches from them
+git-annex remotedaemon - persistent communication with remotes
 
 # SYNOPSIS
 
@@ -8,18 +8,37 @@ git annex remotedaemon
 
 # DESCRIPTION
 
-This plumbing-level command is used by the assistant to detect
-when remotes have received git pushes, so the changes can be promptly
-fetched and the local repository updated.
+The remotedaemon provides persistent communication with remotes.
+This is useful to detect when remotes have received git pushes, so the
+changes can be promptly fetched and the local repository updated.
 
-This is a better alternative to the [[git-annex-xmppgit]](1)
-hack.
+The assistant runs the remotedaemon and communicates with it on
+stdio using a simple textual protocol.
 
-For the remotedaemon to work, the git remote must have
-[[git-annex-shell]](1) installed, with notifychanges support.
-The first version of git-annex-shell that supports it is 5.20140405.
+Several types of remotes are supported:
 
-It's normal for this process to be running when the assistant is running.
+For ssh remotes, the remotedaemon tries to maintain a connection to the
+remote git repository, and uses git-annex-shell notifychanges to detect
+when the remote git repository has changed, and fetch the changes from
+it. For this to work, the git remote must have [[git-annex-shell]](1)
+installed, with notifychanges support. The first version of git-annex-shell
+that supports it is 5.20140405.
+
+For tor-annex remotes, the remotedaemon runs as a tor hidden service,
+accepting connections from other nodes and serving up the contents of the
+repository. This is only done if you first run `git annex enable-tor`.
+
+# OPTIONS
+
+* `--foreground`
+
+Don't fork to the background, and communicate on stdin/stdout using a
+simple textual protocol. The assistant runs the remotedaemon this way.
+
+Commands in the protocol include LOSTNET, which tells the remotedaemon
+that the network connection has been lost, and causes it to stop any TCP
+connctions. That can be followed by RESUME when the network connection
+comes back up.
 
 # SEE ALSO
 
@@ -27,6 +46,8 @@ It's normal for this process to be running when the assistant is running.
 
 [[git-annex-assistant]](1)
 
+[[git-annex-enable-tor]](1)
+
 # AUTHOR
 
 Joey Hess <id@joeyh.name>

doc/git-annex.mdwn

@@ -212,6 +212,12 @@ subdirectories).
   
   See [[git-annex-enableremote]](1) for details.
 
+* `enable-tor`
+
+  Sets up tor hidden service.
+  
+  See [[git-annex-enable-tor]](1) for details.
+
 * `numcopies [N]`
 
   Configure desired number of copies.
@@ -379,6 +385,13 @@ subdirectories).
   
   See [[git-annex-repair]](1) for details.
 
+* `remotedaemon`
+
+  Persistent communication with remotes.
+
+  See [[git-annex-remotedaemon]](1) for details.
+
+
 # QUERY COMMANDS
 
 * `find [path ...]`
@@ -652,12 +665,6 @@ subdirectories).
 
   See [[git-annex-smudge]](1) for details.
 
-* `remotedaemon`
-
-  Detects when network remotes have received git pushes and fetches from them.
-
-  See [[git-annex-remotedaemon]](1) for details.
-
 * `xmppgit`
 
   This command is used internally by the assistant to perform git pulls