Allow optionally configuring git-annex with -fEKG to enable awesome remote monitoring interfaceat http://localhost:4242/

BuildFlags.hs

@@ -59,5 +59,8 @@ buildFlags = filter (not . null)
 #endif
 #ifdef WITH_CRYPTOHASH
 	, "CryptoHash"
+#endif
+#ifdef WITH_EKG
+	, "EKG"
 #endif
 	]

GitAnnex.hs

@@ -5,7 +5,7 @@
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
-{-# LANGUAGE CPP #-}
+{-# LANGUAGE CPP, OverloadedStrings #-}
 
 module GitAnnex where
 
@@ -87,6 +87,9 @@ import qualified Command.XMPPGit
 import qualified Command.Test
 import qualified Command.FuzzTest
 #endif
+#ifdef WITH_EKG
+import System.Remote.Monitoring
+#endif
 
 cmds :: [Command]
 cmds = concat
@@ -169,4 +172,8 @@ header :: String
 header = "git-annex command [option ...]"
 
 run :: [String] -> IO ()
-run args = dispatch True args cmds options [] header Git.CurrentRepo.get
+run args = do
+#ifdef WITH_EKG
+	_ <- forkServer "localhost" 4242
+#endif
+	dispatch True args cmds options [] header Git.CurrentRepo.get

debian/changelog

@@ -1,3 +1,10 @@
+git-annex (4.20131107) UNRELEASED; urgency=low
+
+  * Allow optionally configuring git-annex with -fEKG to enable awesome
+    remote monitoring interfaceat http://localhost:4242/
+
+ -- Joey Hess <joeyh@debian.org>  Wed, 06 Nov 2013 16:14:14 -0400
+
 git-annex (4.20131106) unstable; urgency=low
 
   * Improve local pairing behavior when two computers both try to start

doc/ekg.mdwn

@@ -0,0 +1,14 @@
+You can `cabal configure -fEKG` to build a git-annex that includes
+the EKG remote monitoring interface.
+
+To access the EKG control panel, go to
+<http://localhost:4242/> while a git-annex command is running.
+
+This EKG build is mostly useful for debugging resource usage problems.
+
+[[!img ekg.png caption="git-annex webapp startup, and assistant startup scan"]]
+
+Note that since only one process can open port 4242 at a time, running
+more than one git-annex process with EKG support at the same time can
+result in some "resource busy (Address already in use)" messages -- but
+git-annex will continue to work.

doc/install/cabal.mdwn

@@ -50,3 +50,9 @@ you want, and use cabal as follows inside its source tree:
 	cabal configure
 	cabal build
 	cabal install --bindir=$HOME/bin
+
+## EKG
+
+When building with cabal, you can optionally enable the 
+[[EKG monitoring interface|ekg]]. This is great for debugging resource
+usage problems.

git-annex.cabal

@@ -74,6 +74,10 @@ Flag Quvi
 Flag CryptoHash
   Description: Enable use of cryptohash for checksumming
 
+Flag EKG
+  Description: Enable use of EKG to monitor git-annex as it runs (at http://localhost:4242/)
+  Default: False
+
 Executable git-annex
   Main-Is: git-annex.hs
   Build-Depends: MissingH, hslogger, directory, filepath,
@@ -177,6 +181,11 @@ Executable git-annex
     Build-Depends: aeson
     CPP-Options: -DWITH_QUVI
 
+  if flag(EKG)
+    Build-Depends: ekg
+    GHC-Options: -with-rtsopts=-T
+    CPP-Options: -DWITH_EKG
+
 source-repository head
   type: git
   location: git://git-annex.branchable.com/