upgrade alerts

The webapp will check twice a day, when the network is connected, to see if
it can download a distributon upgrade file. If a newer version is found,
display an upgrade alert.

This will need the autobuilders to set UPGRADE_LOCATION to the url
it can be downloaded from when building git-annex. Only builds with that
set need automatic upgrade alerts.

Currently, the upgrade page just requests the user manually download
and upgrade it. But, all the info is provided to do automated upgrades
in the future.

Note that urls used will need to all be https.

This commit was sponsored by Dirk Kraft.

1 files changed, 87 insertions, 0 deletions

diff --git a/Assistant/Threads/Upgrader.hs b/Assistant/Threads/Upgrader.hs
new file mode 100644
index 000000000..86a42514d
--- /dev/null
+++ b/Assistant/Threads/Upgrader.hs
@@ -0,0 +1,87 @@
+{- git-annex assistant thread to detect when upgrade is needed
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE CPP #-}
+
+module Assistant.Threads.Upgrader (
+	upgraderThread
+) where
+
+import Assistant.Common
+import Assistant.Types.UrlRenderer
+import Assistant.DaemonStatus
+import Assistant.Alert
+import Utility.NotificationBroadcaster
+import Utility.Tmp
+import qualified Build.SysConfig
+import qualified Utility.Url as Url
+import qualified Annex.Url as Url
+import qualified Git.Version
+import Types.Distribution
+#ifdef WITH_WEBAPP
+import Assistant.WebApp.Types
+#endif
+
+import Data.Time.Clock
+import qualified Data.Text as T
+
+upgraderThread :: UrlRenderer -> NamedThread
+upgraderThread urlrenderer = namedThread "Upgrader" $ do
+	checkUpgrade urlrenderer -- TODO: remove
+	when (isJust Build.SysConfig.upgradelocation) $ do
+		h <- liftIO . newNotificationHandle False . networkConnectedNotifier =<< getDaemonStatus
+		go h Nothing
+  where
+  	{- Wait for a network connection event. Then see if it's been
+	 - half a day since the last upgrade check. If so, proceed with
+	 - check. -}
+	go h lastchecked = do
+		liftIO $ waitNotification h
+		now <- liftIO getCurrentTime
+		if maybe True (\t -> diffUTCTime now t > halfday) lastchecked
+			then do
+				checkUpgrade urlrenderer
+				go h =<< Just <$> liftIO getCurrentTime
+			else go h lastchecked
+	halfday = 12 * 60 * 60
+
+checkUpgrade :: UrlRenderer -> Assistant ()
+checkUpgrade urlrenderer = do
+	debug [ "Checking if an upgrade is available." ]
+	go =<< getDistributionInfo
+  where
+	go Nothing = debug [ "Failed to check if upgrade is available." ]
+	go (Just d) = do
+		let installed = Git.Version.normalize Build.SysConfig.packageversion
+		let avail = Git.Version.normalize $ distributionVersion d
+		let old = Git.Version.normalize <$> distributionUrgentUpgrade d
+		if Just installed <= old
+			then canUpgrade Low urlrenderer d
+			else when (installed < avail) $
+				canUpgrade High urlrenderer d
+
+canUpgrade :: AlertPriority -> UrlRenderer -> GitAnnexDistribution -> Assistant ()
+canUpgrade urgency urlrenderer d = do
+#ifdef WITH_WEBAPP
+	button <- mkAlertButton False (T.pack "Upgrade") urlrenderer (ConfigUpgradeR d)
+	void $ addAlert (canUpgradeAlert urgency button)
+#else
+	noop
+#endif
+
+getDistributionInfo :: Assistant (Maybe GitAnnexDistribution)
+getDistributionInfo = do
+	ua <- liftAnnex Url.getUserAgent
+	liftIO $ withTmpFile "git-annex.tmp" $ \tmpfile h -> do
+		hClose h
+		ifM (Url.downloadQuiet distributionInfoUrl [] [] tmpfile ua)
+			( readish <$> readFileStrict tmpfile
+			, return Nothing
+			)
+
+distributionInfoUrl :: String
+distributionInfoUrl = fromJust Build.SysConfig.upgradelocation ++ "/info"