diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,19 @@
+propellor (2.3.0) unstable; urgency=medium
+
+  * Make propellor resistent to changes to shared libraries, such as libffi,
+    which might render the propellor binary unable to run. This is dealt with
+    by checking the binary both when running propellor on a remote host,
+    and by Cron.runPropellor. If the binary doesn't work, it will be rebuilt.
+  * Note that since a new switch had to be added to allow testing the binary,
+    upgrading to this version will cause a rebuild from scratch of propellor.
+  * Added hasLoginShell and shellEnabled.
+  * debCdn changed to new httpredir.debian.org official replacement for
+    http.debian.net.
+  * API change: Added User and Group newtypes, and Properties that
+    used to use the type UserName = String were changed to use them.
+
+ -- Joey Hess <id@joeyh.name>  Wed, 22 Apr 2015 13:46:24 -0400
+
 propellor (2.2.1) unstable; urgency=medium
 
   * userScriptProperty now passes --shell /bin/sh, so it can be used
diff --git a/config-joey.hs b/config-joey.hs
--- a/config-joey.hs
+++ b/config-joey.hs
@@ -30,6 +30,7 @@
 import qualified Propellor.Property.HostingProvider.Linode as Linode
 import qualified Propellor.Property.SiteSpecific.GitHome as GitHome
 import qualified Propellor.Property.SiteSpecific.GitAnnexBuilder as GitAnnexBuilder
+import qualified Propellor.Property.SiteSpecific.IABak as IABak
 import qualified Propellor.Property.SiteSpecific.JoeySites as JoeySites
 
 
@@ -40,11 +41,13 @@
 hosts :: [Host]          --   *             \ | |           '--------'
 hosts =                --                  (o)  `
 	[ darkstar
+	, gnu
 	, clam
 	, orca
 	, kite
 	, elephant
 	, beaver
+	, iabak
 	] ++ monsters
 
 testvm :: Host
@@ -62,7 +65,7 @@
 	& Hostname.searchDomain
 	& Apt.installed ["linux-image-amd64"]
 	& Apt.installed ["ssh"]
-	& User.hasPassword "root"
+	& User.hasPassword (User "root")
 
 darkstar :: Host
 darkstar = host "darkstar.kitenet.net"
@@ -75,6 +78,14 @@
 	& JoeySites.postfixClientRelay (Context "darkstar.kitenet.net")
 	& JoeySites.dkimMilter
 
+gnu :: Host
+gnu = host "gnu.kitenet.net"
+	& Apt.buildDep ["git-annex"] `period` Daily
+	& Docker.configured
+
+	& JoeySites.postfixClientRelay (Context "gnu.kitenet.net")
+	& JoeySites.dkimMilter
+
 clam :: Host
 clam = standardSystem "clam.kitenet.net" Unstable "amd64"
 	[ "Unreliable server. Anything here may be lost at any time!" ]
@@ -163,9 +174,9 @@
 		, "--exclude=.*/tmp/"
 		, "--one-file-system"
 		] Obnam.OnlyClient (Gpg.GpgKeyId "98147487")
-		`requires` Ssh.keyImported SshRsa "root"
+		`requires` Ssh.keyImported SshRsa (User "root")
 			(Context "kite.kitenet.net")
-		`requires` Ssh.knownHost hosts "eubackup.kitenet.net" "root"
+		`requires` Ssh.knownHost hosts "eubackup.kitenet.net" (User "root")
 	& Apt.serviceInstalledRunning "ntp"
 	& "/etc/timezone" `File.hasContent` ["US/Eastern"]
 
@@ -177,7 +188,7 @@
 	
 	& JoeySites.kitenetHttps
 	& JoeySites.legacyWebSites
-	& File.ownerGroup "/srv/web" "joey" "joey"
+	& File.ownerGroup "/srv/web" (User "joey") (Group "joey")
 	& Apt.installed ["analog"]
 	
 	& alias "git.kitenet.net"
@@ -211,7 +222,6 @@
 	
 	& Docker.configured
 	& Docker.garbageCollected `period` Daily
-	! Docker.docked oldusenetShellBox
 	
 	& alias "nntp.olduse.net"
 	& JoeySites.oldUseNetServer hosts
@@ -245,12 +255,12 @@
 	& Apt.unattendedUpgrades
 	& Systemd.installed
 	& Systemd.persistentJournal
-	& Ssh.keyImported SshRsa "joey" hostContext
+	& Ssh.keyImported SshRsa (User "joey") hostContext
 	& Apt.serviceInstalledRunning "swapspace"
 
 	& alias "eubackup.kitenet.net"
 	& Apt.installed ["obnam", "sshfs", "rsync"]
-	& JoeySites.obnamRepos ["wren", "pell", "kite"]
+	& JoeySites.obnamRepos ["pell", "kite"]
 	& JoeySites.githubBackup
 	& JoeySites.rsyncNetBackup hosts
 
@@ -298,9 +308,37 @@
 	& alias "usbackup.kitenet.net"
 	& JoeySites.backupsBackedupFrom hosts "eubackup.kitenet.net" "/home/joey/lib/backup"
 	& Apt.serviceInstalledRunning "anacron"
-	& Cron.niceJob "system disk backed up" Cron.Weekly "root" "/"
+	& Cron.niceJob "system disk backed up" Cron.Weekly (User "root") "/"
 		"rsync -a -x / /home/joey/lib/backup/beaver.kitenet.net/"
 
+iabak :: Host
+iabak = host "iabak.archiveteam.org"
+	& ipv4 "124.6.40.227"
+	& Hostname.sane
+	& os (System (Debian Testing) "amd64")
+	& Systemd.persistentJournal
+	& Cron.runPropellor (Cron.Times "30 * * * *")
+	& Apt.stdSourcesList `onChange` Apt.upgrade
+	& Apt.installed ["git", "ssh"]
+	& Ssh.hostKeys (Context "iabak.archiveteam.org")
+		[ (SshDsa, "ssh-dss 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")
+		, (SshRsa, "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDP13oPRLRY0V9ZDWojb8TgHbUdE30Nq3b541TwPmlLMbYPAhldxGHkuXGlX8g9/FYP/1AgkPcxs2Uc61ZV+1Ss7q7t52f4R0bO4WHqxfdXHd9FlLzMLWxMU3aMr693pGlhnUp3/xH6O6/+bNEIo3VGGgv9XDr2cAxypS9J7X9ibHZcZ3BGvoCR+nnFJ00ERG2tREKZBPDWKk76lhCiM21fG/CSmcApXaA45FHDaM9/2Clj1sXvoS72f0hEKpl1m08sUx+F0GPzQESnKqNFl+xXdYPPbfhdrgCnDmx9tL5NnXsJU2beFiuxpICOeB1HV6DJsdlO18WqwXYhOg/2A1H3")
+		, (SshEcdsa, "ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBHb0kXcrF5ThwS8wB0Hez404Zp9bz78ZxEGSqnwuF4d/N3+bymg7/HAj7l/SzRoEXKHsJ7P5320oMxBHeM16Y+k=")
+		]
+	& Apt.installed ["etckeeper", "sudo"]
+	& Apt.installed ["vim", "screen", "tmux", "less", "emax-nox", "netcat"]
+	& User.hasSomePassword (User "root")
+	& propertyList "admin accounts"
+		(map User.accountFor admins ++ map Sudo.enabledFor admins)
+	& User.hasSomePassword (User "joey")
+	& GitHome.installedFor (User "joey")
+	& Ssh.authorizedKey (User "db48x") "ssh-rsa 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 db48x@anglachel"
+	& Apt.installed ["sudo"]
+	& IABak.gitServer monsters
+	& IABak.registrationServer monsters
+	& IABak.graphiteServer
+  where
+	admins = map User ["joey", "db48x"]
 
        --'                        __|II|      ,.
      ----                      __|II|II|__   (  \_,/\
@@ -323,7 +361,7 @@
 openidProvider = standardStableContainer "openid-provider"
 	& alias "openid.kitenet.net"
 	& Docker.publish "8081:80"
-	& OpenId.providerFor ["joey", "liw"]
+	& OpenId.providerFor [User "joey", User "liw"]
 		"openid.kitenet.net:8081"
 
 -- Exhibit: kite's 90's website.
@@ -332,7 +370,7 @@
 	& alias "ancient.kitenet.net"
 	& Docker.publish "1994:80"
 	& Apt.serviceInstalledRunning "apache2"
-	& Git.cloned "root" "git://kitenet-net.branchable.com/" "/var/www"
+	& Git.cloned (User "root") "git://kitenet-net.branchable.com/" "/var/www"
 		(Just "remotes/origin/old-kitenet.net")
 
 oldusenetShellBox :: Docker.Container
@@ -354,7 +392,7 @@
 	& Docker.publish "2202:22"
 	& Docker.publish "8001:80"
 	& Apt.installed ["ssh"]
-	& User.hasSomePassword "root"
+	& User.hasSomePassword (User "root")
 	& Ssh.permitRootLogin True
 	
 kiteShellBox :: Docker.Container
@@ -369,7 +407,7 @@
 standardSystem hn suite arch motd = standardSystemUnhardened hn suite arch motd
 	-- Harden the system, but only once root's authorized_keys
 	-- is safely in place.
-	& check (Ssh.hasAuthorizedKeys "root")
+	& check (Ssh.hasAuthorizedKeys (User "root"))
 		(Ssh.passwordAuthentication False)
 
 standardSystemUnhardened :: HostName -> DebianSuite -> Architecture -> Motd -> Host
@@ -382,12 +420,12 @@
 	& Apt.cacheCleaned
 	& Apt.installed ["etckeeper"]
 	& Apt.installed ["ssh"]
-	& GitHome.installedFor "root"
-	& User.hasSomePassword "root"
-	& User.accountFor "joey"
-	& User.hasSomePassword "joey"
-	& Sudo.enabledFor "joey"
-	& GitHome.installedFor "joey"
+	& GitHome.installedFor (User "root")
+	& User.hasSomePassword (User "root")
+	& User.accountFor (User "joey")
+	& User.hasSomePassword (User "joey")
+	& Sudo.enabledFor (User "joey")
+	& GitHome.installedFor (User "joey")
 	& Apt.installed ["vim", "screen", "less"]
 	& Cron.runPropellor (Cron.Times "30 * * * *")
 	-- I use postfix, or no MTA.
@@ -446,6 +484,8 @@
 		& Ssh.pubKey SshDsa "ssh-dss AAAAB3NzaC1kc3MAAAEBAI6ZsoW8a+Zl6NqUf9a4xXSMcV1akJHDEKKBzlI2YZo9gb9YoCf5p9oby8THUSgfh4kse7LJeY7Nb64NR6Y/X7I2/QzbE1HGGl5mMwB6LeUcJ74T3TQAlNEZkGt/MOIVLolJHk049hC09zLpkUDtX8K0t1yaCirC9SxDGLTCLEhvU9+vVdVrdQlKZ9wpLUNbdAzvbra+O/IVvExxDZ9WCHrnfNA8ddVZIGEWMqsoNgiuCxiXpi8qL+noghsSQNFTXwo7W2Vp9zj1JkCt3GtSz5IzEpARQaXEAWNEM0n1nJ686YUOhou64iRM8bPC1lp3QXvvZNgj3m+QHhIempx+de8AAAAVAKB5vUDaZOg14gRn7Bp81ja/ik+RAAABACPH/bPbW912x1NxNiikzGR6clLh+bLpIp8Qie3J7DwOr8oC1QOKjNDK+UgQ7mDQEgr4nGjNKSvpDi4c1QCw4sbLqQgx1y2VhT0SmUPHf5NQFldRQyR/jcevSSwOBxszz3aq9AwHiv9OWaO3XY18suXPouiuPTpIcZwc2BLDNHFnDURQeGEtmgqj6gZLIkTY0iw7q9Tj5FOyl4AkvEJC5B4CSzaWgey93Wqn1Imt7KI8+H9lApMKziVL1q+K7xAuNkGmx5YOSNlE6rKAPtsIPHZGxR7dch0GURv2jhh0NQYvBRn3ukCjuIO5gx56HLgilq59/o50zZ4NcT7iASF76TcAAAEAC6YxX7rrs8pp13W4YGiJHwFvIO1yXLGOdqu66JM0plO4J1ItV1AQcazOXLiliny3p2/W+wXZZKd5HIRt52YafCA8YNyMk/sF7JcTR4d4z9CfKaAxh0UpzKiAk+0j/Wu3iPoTOsyt7N0j1+dIyrFodY2sKKuBMT4TQ0yqQpbC+IDQv2i1IlZAPneYGfd5MIGygs2QMfaMQ1jWAKJvEO0vstZ7GB6nDAcg4in3ZiBHtomx3PL5w+zg48S4Ed69BiFXLZ1f6MnjpUOP75pD4MP6toS0rgK9b93xCrEQLgm4oD/7TCHHBo2xR7wwcsN2OddtwWsEM2QgOkt/jdCAoVCqwQ=="
 	, host "github.com" 
 		& Ssh.pubKey SshRsa "ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ=="
+	, host "gitlab.com"
+		& Ssh.pubKey SshEcdsa "ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBFSMqzJeV9rUzU4kWitGjeR4PWSa29SPqJ1fVkhtj3Hw9xjLVXVYrU9QlYWrOLXBpQ6KWjbjTDTdDkoohFzgbEY="
 	, host "ns6.gandi.net"
 		& ipv4 "217.70.177.40"
 	, host "turtle.kitenet.net"
diff --git a/config-simple.hs b/config-simple.hs
--- a/config-simple.hs
+++ b/config-simple.hs
@@ -28,7 +28,7 @@
 		& Apt.unattendedUpgrades
 		& Apt.installed ["etckeeper"]
 		& Apt.installed ["ssh"]
-		& User.hasSomePassword "root"
+		& User.hasSomePassword (User "root")
 		& Network.ipv6to4
 		& File.dirExists "/var/www"
 		& Docker.docked webserverContainer
@@ -41,8 +41,8 @@
 
 -- A generic webserver in a Docker container.
 webserverContainer :: Docker.Container
-webserverContainer = Docker.container "webserver" "joeyh/debian-stable"
-	& os (System (Debian (Stable "wheezy")) "amd64")
+webserverContainer = Docker.container "webserver" "debian"
+	& os (System (Debian (Stable "jessie")) "amd64")
 	& Apt.stdSourcesList
 	& Docker.publish "80:80"
 	& Docker.volume "/var/www:/var/www"
diff --git a/config.hs b/config.hs
--- a/config.hs
+++ b/config.hs
@@ -28,7 +28,7 @@
 		& Apt.unattendedUpgrades
 		& Apt.installed ["etckeeper"]
 		& Apt.installed ["ssh"]
-		& User.hasSomePassword "root"
+		& User.hasSomePassword (User "root")
 		& Network.ipv6to4
 		& File.dirExists "/var/www"
 		& Docker.docked webserverContainer
@@ -41,8 +41,8 @@
 
 -- A generic webserver in a Docker container.
 webserverContainer :: Docker.Container
-webserverContainer = Docker.container "webserver" "joeyh/debian-stable"
-	& os (System (Debian (Stable "wheezy")) "amd64")
+webserverContainer = Docker.container "webserver" "debian"
+	& os (System (Debian (Stable "jessie")) "amd64")
 	& Apt.stdSourcesList
 	& Docker.publish "80:80"
 	& Docker.volume "/var/www:/var/www"
diff --git a/debian/changelog b/debian/changelog
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,19 @@
+propellor (2.3.0) unstable; urgency=medium
+
+  * Make propellor resistent to changes to shared libraries, such as libffi,
+    which might render the propellor binary unable to run. This is dealt with
+    by checking the binary both when running propellor on a remote host,
+    and by Cron.runPropellor. If the binary doesn't work, it will be rebuilt.
+  * Note that since a new switch had to be added to allow testing the binary,
+    upgrading to this version will cause a rebuild from scratch of propellor.
+  * Added hasLoginShell and shellEnabled.
+  * debCdn changed to new httpredir.debian.org official replacement for
+    http.debian.net.
+  * API change: Added User and Group newtypes, and Properties that
+    used to use the type UserName = String were changed to use them.
+
+ -- Joey Hess <id@joeyh.name>  Wed, 22 Apr 2015 13:46:24 -0400
+
 propellor (2.2.1) unstable; urgency=medium
 
   * userScriptProperty now passes --shell /bin/sh, so it can be used
diff --git a/debian/rules b/debian/rules
--- a/debian/rules
+++ b/debian/rules
@@ -12,7 +12,3 @@
 	dh_installdocs doc/README.mdwn
 override_dh_installman:
 	dh_installman propellor.1
-
-# Not intended for use by anyone except the author.
-announcedir:
-	@echo ${HOME}/src/propellor/doc/news
diff --git a/propellor.cabal b/propellor.cabal
--- a/propellor.cabal
+++ b/propellor.cabal
@@ -1,5 +1,5 @@
 Name: propellor
-Version: 2.2.1
+Version: 2.3.0
 Cabal-Version: >= 1.6
 License: BSD3
 Maintainer: Joey Hess <id@joeyh.name>
diff --git a/src/Propellor/Bootstrap.hs b/src/Propellor/Bootstrap.hs
--- a/src/Propellor/Bootstrap.hs
+++ b/src/Propellor/Bootstrap.hs
@@ -1,5 +1,6 @@
 module Propellor.Bootstrap (
 	bootstrapPropellorCommand,
+	checkBinaryCommand,
 	installGitCommand,
 	buildPropellor,
 ) where
@@ -12,14 +13,24 @@
 
 type ShellCommand = String
 
--- Shell command line to build propellor, used when bootstrapping on a new
--- host. Should be run inside the propellor config dir, and will install
--- all necessary build dependencies.
+-- Shell command line to ensure propellor is bootstrapped and ready to run.
+-- Should be run inside the propellor config dir, and will install
+-- all necessary build dependencies and build propellor.
 bootstrapPropellorCommand :: ShellCommand
-bootstrapPropellorCommand = "if ! test -x ./propellor; then " ++ go ++ "; fi"
+bootstrapPropellorCommand = "if ! test -x ./propellor; then " ++ go ++ "; fi;" ++ checkBinaryCommand
   where
-	go = intercalate " && "
+	  go = intercalate " && "
 		[ depsCommand
+		, buildCommand
+		]
+
+-- Use propellor --check to detect if the local propellor binary has
+-- stopped working (eg due to library changes), and must be rebuilt.
+checkBinaryCommand :: ShellCommand
+checkBinaryCommand = "if test -x ./propellor && ! ./propellor --check 2>/dev/null; then " ++ go ++ "; fi"
+  where
+	go = intercalate " && "
+		[ "cabal clean"
 		, buildCommand
 		]
 
diff --git a/src/Propellor/CmdLine.hs b/src/Propellor/CmdLine.hs
--- a/src/Propellor/CmdLine.hs
+++ b/src/Propellor/CmdLine.hs
@@ -33,6 +33,7 @@
 	, "  propellor --list-fields"
 	, "  propellor --merge"
 	, "  propellor --build"
+	, "  propellor --check"
 	]
 
 usageError :: [String] -> IO a
@@ -43,6 +44,7 @@
 processCmdLine :: IO CmdLine
 processCmdLine = go =<< getArgs
   where
+  	go ("--check":_) = return Check
 	go ("--spin":ps) = case reverse ps of
 		(r:"--via":hs) -> Spin 
 			<$> mapM hostname (reverse hs) 
@@ -91,6 +93,7 @@
   where
 	go _ (Serialized cmdline) = go True cmdline
 	go _ (Continue cmdline) = go False cmdline
+	go _ Check = return ()
 	go _ (Set field context) = setPrivData field context
 	go _ (Dump field context) = dumpPrivData field context
 	go _ (Edit field context) = editPrivData field context
diff --git a/src/Propellor/Property/Apt.hs b/src/Propellor/Property/Apt.hs
--- a/src/Propellor/Property/Apt.hs
+++ b/src/Propellor/Property/Apt.hs
@@ -61,7 +61,7 @@
 		return $ debLine bs url stdSections
 
 debCdn :: SourcesGenerator
-debCdn = binandsrc "http://http.debian.net/debian"
+debCdn = binandsrc "http://httpredir.debian.org/debian"
 
 kernelOrg :: SourcesGenerator
 kernelOrg = binandsrc "http://mirrors.kernel.org/debian"
diff --git a/src/Propellor/Property/Cmd.hs b/src/Propellor/Property/Cmd.hs
--- a/src/Propellor/Property/Cmd.hs
+++ b/src/Propellor/Property/Cmd.hs
@@ -39,7 +39,7 @@
 
 -- | A property that can satisfied by running a series of shell commands,
 -- as user (cd'd to their home directory).
-userScriptProperty :: UserName -> [String] -> Property NoInfo
-userScriptProperty user script = cmdProperty "su" ["--shell", "/bin/sh", "-c", shellcmd, user]
+userScriptProperty :: User -> [String] -> Property NoInfo
+userScriptProperty (User user) script = cmdProperty "su" ["--shell", "/bin/sh", "-c", shellcmd, user]
   where
 	shellcmd = intercalate " ; " ("set -e" : "cd" : script)
diff --git a/src/Propellor/Property/Cron.hs b/src/Propellor/Property/Cron.hs
--- a/src/Propellor/Property/Cron.hs
+++ b/src/Propellor/Property/Cron.hs
@@ -3,6 +3,7 @@
 import Propellor
 import qualified Propellor.Property.File as File
 import qualified Propellor.Property.Apt as Apt
+import Propellor.Bootstrap
 import Utility.SafeCommand
 import Utility.FileMode
 
@@ -27,8 +28,8 @@
 -- job file.
 --
 -- The cron job's output will only be emailed if it exits nonzero.
-job :: Desc -> Times -> UserName -> FilePath -> String -> Property NoInfo
-job desc times user cddir command = combineProperties ("cronned " ++ desc)
+job :: Desc -> Times -> User -> FilePath -> String -> Property NoInfo
+job desc times (User u) cddir command = combineProperties ("cronned " ++ desc)
 	[ cronjobfile `File.hasContent`
 		[ case times of
 			Times _ -> ""
@@ -39,10 +40,10 @@
 		, "PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin"
 		, ""
 		, case times of
-			Times t -> t ++ "\t" ++ user ++ "\tchronic " ++ shellEscape scriptfile
-			_ -> case user of
+			Times t -> t ++ "\t" ++ u ++ "\tchronic " ++ shellEscape scriptfile
+			_ -> case u of
 				"root" -> "chronic " ++ shellEscape scriptfile
-				_ -> "chronic su " ++ user ++ " -c " ++ shellEscape scriptfile
+				_ -> "chronic su " ++ u ++ " -c " ++ shellEscape scriptfile
 		]
 	, case times of
 		Times _ -> doNothing
@@ -75,10 +76,11 @@
 		| otherwise = '_'
 
 -- | Installs a cron job, and runs it niced and ioniced.
-niceJob :: Desc -> Times -> UserName -> FilePath -> String -> Property NoInfo
+niceJob :: Desc -> Times -> User -> FilePath -> String -> Property NoInfo
 niceJob desc times user cddir command = job desc times user cddir
 	("nice ionice -c 3 sh -c " ++ shellEscape command)
 
 -- | Installs a cron job to run propellor.
 runPropellor :: Times -> Property NoInfo
-runPropellor times = niceJob "propellor" times "root" localdir "./propellor"
+runPropellor times = niceJob "propellor" times (User "root") localdir
+	(bootstrapPropellorCommand ++ "; ./propellor")
diff --git a/src/Propellor/Property/File.hs b/src/Propellor/Property/File.hs
--- a/src/Propellor/Property/File.hs
+++ b/src/Propellor/Property/File.hs
@@ -91,8 +91,8 @@
 	makeChange $ createDirectoryIfMissing True d
 
 -- | Ensures that a file/dir has the specified owner and group.
-ownerGroup :: FilePath -> UserName -> GroupName -> Property NoInfo
-ownerGroup f owner group = property (f ++ " owner " ++ og) $ do
+ownerGroup :: FilePath -> User -> Group -> Property NoInfo
+ownerGroup f (User owner) (Group group) = property (f ++ " owner " ++ og) $ do
 	r <- ensureProperty $ cmdProperty "chown" [og, f]
 	if r == FailedChange
 		then return r
diff --git a/src/Propellor/Property/Git.hs b/src/Propellor/Property/Git.hs
--- a/src/Propellor/Property/Git.hs
+++ b/src/Propellor/Property/Git.hs
@@ -62,7 +62,7 @@
 -- it will be recursively deleted first.
 --
 -- A branch can be specified, to check out.
-cloned :: UserName -> RepoUrl -> FilePath -> Maybe Branch -> Property NoInfo
+cloned :: User -> RepoUrl -> FilePath -> Maybe Branch -> Property NoInfo
 cloned owner url dir mbranch = check originurl (property desc checkout)
 	`requires` installed
   where
@@ -96,17 +96,17 @@
 isGitDir :: FilePath -> IO Bool
 isGitDir dir = isNothing <$> catchMaybeIO (readProcess "git" ["rev-parse", "--resolve-git-dir", dir])
 
-data GitShared = Shared GroupName | SharedAll | NotShared
+data GitShared = Shared Group | SharedAll | NotShared
 
-bareRepo :: FilePath -> UserName -> GitShared -> Property NoInfo
+bareRepo :: FilePath -> User -> GitShared -> Property NoInfo
 bareRepo repo user gitshared = check (isRepo repo) $ propertyList ("git repo: " ++ repo) $
 	dirExists repo : case gitshared of
 		NotShared ->
-			[ ownerGroup repo user user
+			[ ownerGroup repo user (userGroup user)
 			, userScriptProperty user ["git", "init", "--bare", "--shared=false", repo]
 			]
 		SharedAll ->
-			[ ownerGroup repo user user
+			[ ownerGroup repo user (userGroup user)
 			, userScriptProperty user ["git", "init", "--bare", "--shared=all", repo]
 			]
 		Shared group' ->
diff --git a/src/Propellor/Property/Gpg.hs b/src/Propellor/Property/Gpg.hs
--- a/src/Propellor/Property/Gpg.hs
+++ b/src/Propellor/Property/Gpg.hs
@@ -20,24 +20,24 @@
 --
 -- Recommend only using this for low-value dedicated role keys.
 -- No attempt has been made to scrub the key out of memory once it's used.
-keyImported :: GpgKeyId -> UserName -> Property HasInfo
-keyImported (GpgKeyId keyid) user = flagFile' prop genflag
+keyImported :: GpgKeyId -> User -> Property HasInfo
+keyImported (GpgKeyId keyid) user@(User u) = flagFile' prop genflag
 	`requires` installed
   where
-	desc = user ++ " has gpg key " ++ show keyid
+	desc = u ++ " has gpg key " ++ show keyid
 	genflag = do
 		d <- dotDir user
 		return $ d </> ".propellor-imported-keyid-" ++ keyid
 	prop = withPrivData src (Context keyid) $ \getkey ->
 		property desc $ getkey $ \key -> makeChange $
 			withHandle StdinHandle createProcessSuccess
-				(proc "su" ["-c", "gpg --import", user]) $ \h -> do
+				(proc "su" ["-c", "gpg --import", u]) $ \h -> do
 					fileEncoding h
 					hPutStr h key
 					hClose h
 	src = PrivDataSource GpgKey "Either a gpg public key, exported with gpg --export -a, or a gpg private key, exported with gpg --export-secret-key -a"
 
-dotDir :: UserName -> IO FilePath
-dotDir user = do
-	home <- homeDirectory <$> getUserEntryForName user
+dotDir :: User -> IO FilePath
+dotDir (User u) = do
+	home <- homeDirectory <$> getUserEntryForName u
 	return $ home </> ".gnupg"
diff --git a/src/Propellor/Property/Group.hs b/src/Propellor/Property/Group.hs
--- a/src/Propellor/Property/Group.hs
+++ b/src/Propellor/Property/Group.hs
@@ -4,8 +4,8 @@
 
 type GID = Int
 
-exists :: GroupName -> Maybe GID -> Property NoInfo
-exists group' mgid = check test (cmdProperty "addgroup" $ args mgid)
+exists :: Group -> Maybe GID -> Property NoInfo
+exists (Group group') mgid = check test (cmdProperty "addgroup" $ args mgid)
 	`describe` unwords ["group", group']
   where
 	groupFile = "/etc/group"
diff --git a/src/Propellor/Property/HostingProvider/CloudAtCost.hs b/src/Propellor/Property/HostingProvider/CloudAtCost.hs
--- a/src/Propellor/Property/HostingProvider/CloudAtCost.hs
+++ b/src/Propellor/Property/HostingProvider/CloudAtCost.hs
@@ -17,7 +17,7 @@
 		[ File.notPresent "/etc/rc.local"
 		, File.notPresent "/etc/init.d/S97-setup.sh"
 		, File.notPresent "/zang-debian.sh"
-		, User.nuked "user" User.YesReallyDeleteHome
+		, User.nuked (User "user") User.YesReallyDeleteHome
 		]
 	]
 
diff --git a/src/Propellor/Property/OS.hs b/src/Propellor/Property/OS.hs
--- a/src/Propellor/Property/OS.hs
+++ b/src/Propellor/Property/OS.hs
@@ -222,7 +222,7 @@
 preserveRootSshAuthorized = check (fileExist oldloc) $
 	property (newloc ++ " copied from old OS") $ do
 		ks <- liftIO $ lines <$> readFile oldloc
-		ensureProperties (map (Ssh.authorizedKey "root") ks)
+		ensureProperties (map (Ssh.authorizedKey (User "root")) ks)
   where
 	newloc = "/root/.ssh/authorized_keys"
 	oldloc = oldOSDir ++ newloc
diff --git a/src/Propellor/Property/Obnam.hs b/src/Propellor/Property/Obnam.hs
--- a/src/Propellor/Property/Obnam.hs
+++ b/src/Propellor/Property/Obnam.hs
@@ -49,7 +49,7 @@
 backupEncrypted :: FilePath -> Cron.Times -> [ObnamParam] -> NumClients -> Gpg.GpgKeyId -> Property HasInfo
 backupEncrypted dir crontimes params numclients keyid =
 	backup dir crontimes params' numclients
-		`requires` Gpg.keyImported keyid "root"
+		`requires` Gpg.keyImported keyid (User "root")
   where
 	params' = ("--encrypt-with=" ++ Gpg.getGpgKeyId keyid) : params
 
@@ -58,7 +58,7 @@
 backup' dir crontimes params numclients = cronjob `describe` desc
   where
 	desc = dir ++ " backed up by obnam"
-	cronjob = Cron.niceJob ("obnam_backup" ++ dir) crontimes "root" "/" $
+	cronjob = Cron.niceJob ("obnam_backup" ++ dir) crontimes (User "root") "/" $
 		intercalate ";" $ catMaybes
 			[ if numclients == OnlyClient
 				then Just $ unwords $
diff --git a/src/Propellor/Property/OpenId.hs b/src/Propellor/Property/OpenId.hs
--- a/src/Propellor/Property/OpenId.hs
+++ b/src/Propellor/Property/OpenId.hs
@@ -7,7 +7,7 @@
 
 import Data.List
 
-providerFor :: [UserName] -> String -> Property HasInfo
+providerFor :: [User] -> String -> Property HasInfo
 providerFor users baseurl = propertyList desc $ map toProp
 	[ Apt.serviceInstalledRunning "apache2"
 	, Apt.installed ["simpleid"]
@@ -25,6 +25,6 @@
 	
 	-- the identities directory controls access, so open up
 	-- file mode
-	identfile u = File.hasPrivContentExposed
+	identfile (User u) = File.hasPrivContentExposed
 		(concat [ "/var/lib/simpleid/identities/", u, ".identity" ])
 		(Context baseurl)
diff --git a/src/Propellor/Property/Postfix.hs b/src/Propellor/Property/Postfix.hs
--- a/src/Propellor/Property/Postfix.hs
+++ b/src/Propellor/Property/Postfix.hs
@@ -153,6 +153,6 @@
 	dirperm = check (not <$> doesDirectoryExist dir) $ 
 		cmdProperty "dpkg-statoverride"
 			[ "--add", "root", "sasl", "710", dir ]
-	postfixgroup = "postfix" `User.hasGroup` "sasl"
+	postfixgroup = (User "postfix") `User.hasGroup` (Group "sasl")
 		`onChange` restarted
 	dir = "/var/spool/postfix/var/run/saslauthd"
diff --git a/src/Propellor/Property/SiteSpecific/GitAnnexBuilder.hs b/src/Propellor/Property/SiteSpecific/GitAnnexBuilder.hs
--- a/src/Propellor/Property/SiteSpecific/GitAnnexBuilder.hs
+++ b/src/Propellor/Property/SiteSpecific/GitAnnexBuilder.hs
@@ -28,7 +28,7 @@
 autobuilder :: Architecture -> Times -> TimeOut -> Property HasInfo
 autobuilder arch crontimes timeout = combineProperties "gitannexbuilder" $ props
 	& Apt.serviceInstalledRunning "cron"
-	& Cron.niceJob "gitannexbuilder" crontimes builduser gitbuilderdir
+	& Cron.niceJob "gitannexbuilder" crontimes (User builduser) gitbuilderdir
 		("git pull ; timeout " ++ timeout ++ " ./autobuild")
 	& rsyncpassword
   where
@@ -51,18 +51,18 @@
 	-- gitbuilderdir directory already exists when docker volume is used,
 	-- but with wrong owner.
 	& File.dirExists gitbuilderdir
-	& File.ownerGroup gitbuilderdir builduser builduser
+	& File.ownerGroup gitbuilderdir (User builduser) (Group builduser)
 	& gitannexbuildercloned
 	& builddircloned
   where
 	gitannexbuildercloned = check (not <$> (doesDirectoryExist (gitbuilderdir </> ".git"))) $ 
-		userScriptProperty builduser
+		userScriptProperty (User builduser)
 			[ "git clone git://git.kitenet.net/gitannexbuilder " ++ gitbuilderdir
 			, "cd " ++ gitbuilderdir
 			, "git checkout " ++ buildarch
 			]
 			`describe` "gitbuilder setup"
-	builddircloned = check (not <$> doesDirectoryExist builddir) $ userScriptProperty builduser
+	builddircloned = check (not <$> doesDirectoryExist builddir) $ userScriptProperty (User builduser)
 		[ "git clone git://git-annex.branchable.com/ " ++ builddir
 		]
 
@@ -89,7 +89,7 @@
 cabalDeps :: Property NoInfo
 cabalDeps = flagFile go cabalupdated
 	where
-		go = userScriptProperty builduser ["cabal update && cabal install git-annex --only-dependencies || true"]
+		go = userScriptProperty (User builduser) ["cabal update && cabal install git-annex --only-dependencies || true"]
 		cabalupdated = homedir </> ".cabal" </> "packages" </> "hackage.haskell.org" </> "00-index.cache"
 
 standardAutoBuilderContainer :: (System -> Docker.Image) -> Architecture -> Int -> TimeOut -> Docker.Container
@@ -99,7 +99,7 @@
 	& Apt.stdSourcesList
 	& Apt.installed ["systemd"]
 	& Apt.unattendedUpgrades
-	& User.accountFor builduser
+	& User.accountFor (User builduser)
 	& tree arch
 	& buildDepsApt
 	& autobuilder arch (Cron.Times $ show buildminute ++ " * * * *") timeout
@@ -125,9 +125,9 @@
 	& Apt.stdSourcesList
 	& Apt.installed ["systemd"]
 	& Docker.tweaked
-	& User.accountFor builduser
+	& User.accountFor (User builduser)
 	& File.dirExists gitbuilderdir
-	& File.ownerGroup homedir builduser builduser
+	& File.ownerGroup homedir (User builduser) (Group builduser)
 	& buildDepsApt
 	& flagFile chrootsetup ("/chrootsetup")
 		`requires` setupgitannexdir
@@ -139,7 +139,7 @@
 	chrootsetup = scriptProperty
 		[ "cd " ++ gitannexdir ++ " && ./standalone/android/buildchroot-inchroot"
 		]
-	haskellpkgsinstalled = userScriptProperty "builder"
+	haskellpkgsinstalled = userScriptProperty (User builduser)
 		[ "cd " ++ gitannexdir ++ " && ./standalone/android/install-haskell-packages"
 		]
 	osver = System (Debian Testing) "i386" -- once jessie is released, use: (Stable "jessie")
@@ -155,7 +155,7 @@
 	& Apt.installed ["systemd"]
 	-- This volume is shared with the armel builder.
 	& Docker.volume gitbuilderdir
-	& User.accountFor builduser
+	& User.accountFor (User builduser)
 	-- Install current versions of build deps from cabal.
 	& tree "armel"
 	& buildDepsNoHaskellLibs
@@ -163,7 +163,7 @@
 	-- The armel builder can ssh to this companion.
 	& Docker.expose "22"
 	& Apt.serviceInstalledRunning "ssh"
-	& Ssh.authorizedKeys builduser (Context "armel-git-annex-builder")
+	& Ssh.authorizedKeys (User builduser) (Context "armel-git-annex-builder")
 	& Docker.tweaked
 
 armelAutoBuilderContainer :: (System -> Docker.Image) -> Times -> TimeOut -> Docker.Container
@@ -175,7 +175,7 @@
 	& Apt.installed ["openssh-client"]
 	& Docker.link "armel-git-annex-builder-companion" "companion"
 	& Docker.volumes_from "armel-git-annex-builder-companion"
-	& User.accountFor builduser
+	& User.accountFor (User builduser)
 	-- TODO: automate installing haskell libs
 	-- (Currently have to run
 	-- git-annex/standalone/linux/install-haskell-packages
@@ -183,7 +183,7 @@
 	& buildDepsNoHaskellLibs
 	& autobuilder "armel" crontimes timeout
 		`requires` tree "armel"
-	& Ssh.keyImported SshRsa builduser (Context "armel-git-annex-builder")
+	& Ssh.keyImported SshRsa (User builduser) (Context "armel-git-annex-builder")
 	& trivial writecompanionaddress
 	& Docker.tweaked
   where
diff --git a/src/Propellor/Property/SiteSpecific/GitHome.hs b/src/Propellor/Property/SiteSpecific/GitHome.hs
--- a/src/Propellor/Property/SiteSpecific/GitHome.hs
+++ b/src/Propellor/Property/SiteSpecific/GitHome.hs
@@ -6,9 +6,9 @@
 import Utility.SafeCommand
 
 -- | Clones Joey Hess's git home directory, and runs its fixups script.
-installedFor :: UserName -> Property NoInfo
-installedFor user = check (not <$> hasGitDir user) $ 
-	property ("githome " ++ user) (go =<< liftIO (homedir user))
+installedFor :: User -> Property NoInfo
+installedFor user@(User u) = check (not <$> hasGitDir user) $ 
+	property ("githome " ++ u) (go =<< liftIO (homedir user))
 		`requires` Apt.installed ["git"]
   where
 	go home = do
@@ -28,7 +28,7 @@
 url :: String
 url = "git://git.kitenet.net/joey/home"
 
-hasGitDir :: UserName -> IO Bool
+hasGitDir :: User -> IO Bool
 hasGitDir user = go =<< homedir user
   where
 	go home = doesDirectoryExist (home </> ".git")
diff --git a/src/Propellor/Property/SiteSpecific/JoeySites.hs b/src/Propellor/Property/SiteSpecific/JoeySites.hs
--- a/src/Propellor/Property/SiteSpecific/JoeySites.hs
+++ b/src/Propellor/Property/SiteSpecific/JoeySites.hs
@@ -24,14 +24,15 @@
 
 scrollBox :: Property HasInfo
 scrollBox = propertyList "scroll server" $ props
-	& User.accountFor "scroll"
-	& Git.cloned "scroll" "git://git.kitenet.net/scroll" (d </> "scroll") Nothing
+	& User.accountFor (User "scroll")
+	& Git.cloned (User "scroll") "git://git.kitenet.net/scroll" (d </> "scroll") Nothing
 	& Apt.installed ["ghc", "make", "cabal-install", "libghc-vector-dev",
 		"libghc-bytestring-dev", "libghc-mtl-dev", "libghc-ncurses-dev",
-		"libghc-random-dev", "libghc-monad-loops-dev",
+		"libghc-random-dev", "libghc-monad-loops-dev", "libghc-text-dev",
 		"libghc-ifelse-dev", "libghc-case-insensitive-dev",
-		"libghc-data-default-dev"]
-	& userScriptProperty "scroll"
+		"libghc-transformers-dev",
+		"libghc-data-default-dev", "libghc-optparse-applicative-dev"]
+	& userScriptProperty (User "scroll")
 		[ "cd " ++ d </> "scroll"
 		, "git pull"
 		, "cabal configure"
@@ -49,13 +50,16 @@
 		, "mkdir \"$t\""
 		, "cd \"$t\""
 		, "echo"
+		, "echo Note that games on this server are time-limited to 2 hours"
+		, "echo 'Need more time? Run scroll locally instead!'"
+		, "echo"
 		, "echo Press Enter to start the game."
 		, "read me"
 		, "SHELL=/bin/sh script --timing=timing -c " ++ g
 		] `onChange` (s `File.mode` (combineModes (ownerWriteMode:readModes ++ executeModes)))
 	& g `File.hasContent`
 		[ "#!/bin/sh"
-		, "if ! ../../scroll/scroll; then"
+		, "if ! timeout --kill-after 1m --foreground 2h ../../scroll/scroll; then"
 		, "echo Scroll seems to have ended unexpectedly. Possibly a bug.."
 		, "else"
 		, "echo Thanks for playing scroll! https://joeyh.name/code/scroll/"
@@ -65,14 +69,14 @@
 		, "echo 'or, type comments below (finish with a dot on its own line)'"
 		, "echo"
 		, "echo Your comments:"
-		, "mail -s \"scroll test $t\" joey@kitenet.net"
+		, "timeout --kill-after 1m --foreground 2h mail -E -s \"scroll test $t\" joey@kitenet.net"
 		] `onChange` (g `File.mode` (combineModes (ownerWriteMode:readModes ++ executeModes)))
 	& Apt.installed ["bsd-mailx"]
 	-- prevent port forwarding etc by not letting scroll log in via ssh
 	& Ssh.sshdConfig `File.containsLine` ("DenyUsers scroll")
 		`onChange` Ssh.restarted
-	& cmdProperty "chsh" ["scroll", "-s", s]
-	& User.hasPassword "scroll"
+	& User.shellSetTo (User "scroll") s
+	& User.hasPassword (User "scroll")
 	& Apt.serviceInstalledRunning "telnetd"
 	& Apt.installed ["shellinabox"]
 	& File.hasContent "/etc/default/shellinabox"
@@ -111,8 +115,8 @@
 	& Apt.serviceInstalledRunning "openbsd-inetd"
 	& File.notPresent "/etc/cron.daily/leafnode"
 	& File.notPresent "/etc/cron.d/leafnode"
-	& Cron.niceJob "oldusenet-expire" (Cron.Times "11 1 * * *") "news" newsspool expirecommand
-	& Cron.niceJob "oldusenet-uucp" (Cron.Times "*/5 * * * *") "news" "/" uucpcommand
+	& Cron.niceJob "oldusenet-expire" (Cron.Times "11 1 * * *") (User "news") newsspool expirecommand
+	& Cron.niceJob "oldusenet-uucp" (Cron.Times "*/5 * * * *") (User "news") "/" uucpcommand
 	& Apache.siteEnabled "nntp.olduse.net" nntpcfg
   where
 	newsspool = "/var/spool/news"
@@ -136,8 +140,8 @@
 		, "--client-name=spool"
 		, "--ssh-key=" ++ keyfile
 		] Obnam.OnlyClient
-		`requires` Ssh.keyImported' (Just keyfile) SshRsa "root" (Context "olduse.net")
-		`requires` Ssh.knownHost hosts "usw-s002.rsync.net" "root"
+		`requires` Ssh.keyImported' (Just keyfile) SshRsa (User "root") (Context "olduse.net")
+		`requires` Ssh.knownHost hosts "usw-s002.rsync.net" (User "root")
 	keyfile = "/root/.ssh/olduse.net.key"
 
 oldUseNetShellBox :: Property HasInfo
@@ -185,8 +189,8 @@
 		[ "--repository=sftp://2318@usw-s002.rsync.net/~/" ++ hn ++ ".obnam"
 		, "--client-name=mumble"
 		] Obnam.OnlyClient
-		`requires` Ssh.keyImported SshRsa "root" (Context hn)
-		`requires` Ssh.knownHost hosts "usw-s002.rsync.net" "root"
+		`requires` Ssh.keyImported SshRsa (User "root") (Context hn)
+		`requires` Ssh.knownHost hosts "usw-s002.rsync.net" (User "root")
 	& trivial (cmdProperty "chown" ["-R", "mumble-server:mumble-server", "/var/lib/mumble-server"])
   where
 	hn = "mumble.debian.net"
@@ -200,10 +204,10 @@
 		, "--ssh-key=" ++ sshkey
 		, "--client-name=wren" -- historical
 		] Obnam.OnlyClient (Gpg.GpgKeyId "1B169BE1")
-		`requires` Ssh.keyImported' (Just sshkey) SshRsa "root" (Context "git.kitenet.net")
-		`requires` Ssh.knownHost hosts "usw-s002.rsync.net" "root"
-		`requires` Ssh.authorizedKeys "family" (Context "git.kitenet.net")
-		`requires` User.accountFor "family"
+		`requires` Ssh.keyImported' (Just sshkey) SshRsa (User "root") (Context "git.kitenet.net")
+		`requires` Ssh.knownHost hosts "usw-s002.rsync.net" (User "root")
+		`requires` Ssh.authorizedKeys (User "family") (Context "git.kitenet.net")
+		`requires` User.accountFor (User "family")
 	& Apt.installed ["git", "rsync", "gitweb"]
 	& Apt.installed ["git-annex"]
 	& Apt.installed ["kgb-client"]
@@ -218,9 +222,9 @@
 		]
 		`describe` "gitweb configured"
 	-- Repos push on to github.
-	& Ssh.knownHost hosts "github.com" "joey"
+	& Ssh.knownHost hosts "github.com" (User "joey")
 	-- I keep the website used for gitweb checked into git..
-	& Git.cloned "root" "/srv/git/joey/git.kitenet.net.git" "/srv/web/git.kitenet.net" Nothing
+	& Git.cloned (User "root") "/srv/git/joey/git.kitenet.net.git" "/srv/web/git.kitenet.net" Nothing
 	& website "git.kitenet.net"
 	& website "git.joeyh.name"
 	& Apache.modEnabled "cgi"
@@ -248,7 +252,7 @@
 -- | A website, with files coming from a git-annex repository.
 annexWebSite :: Git.RepoUrl -> HostName -> AnnexUUID -> [(String, Git.RepoUrl)] -> Property HasInfo
 annexWebSite origin hn uuid remotes = propertyList (hn ++" website using git-annex") $ props
-	& Git.cloned "joey" origin dir Nothing
+	& Git.cloned (User "joey") origin dir Nothing
 		`onChange` setup
 	& alias hn
 	& postupdatehook `File.hasContent`
@@ -260,7 +264,7 @@
   where
 	dir = "/srv/web/" ++ hn
 	postupdatehook = dir </> ".git/hooks/post-update"
-	setup = userScriptProperty "joey" setupscript
+	setup = userScriptProperty (User "joey") setupscript
 	setupscript = 
 		[ "cd " ++ shellEscape dir
 		, "git annex reinit " ++ shellEscape uuid
@@ -340,11 +344,11 @@
 	& endpoint "/srv/web/downloads.kitenet.net/git-annex/autobuild/x86_64-apple-yosemite"
 	& endpoint "/srv/web/downloads.kitenet.net/git-annex/autobuild/windows"
 	-- git-annex distribution signing key
-	& Gpg.keyImported (Gpg.GpgKeyId "89C809CB") "joey"
+	& Gpg.keyImported (Gpg.GpgKeyId "89C809CB") (User "joey")
   where
 	endpoint d = combineProperties ("endpoint " ++ d)
 		[ File.dirExists d
-		, File.ownerGroup d "joey" "joey"
+		, File.ownerGroup d (User "joey") (Group "joey")
 		]
 
 downloads :: [Host] -> Property HasInfo
@@ -352,7 +356,7 @@
 	"downloads.kitenet.net"
 	"840760dc-08f0-11e2-8c61-576b7e66acfd"
 	[("eubackup", "ssh://eubackup.kitenet.net/~/lib/downloads/")]
-	`requires` Ssh.knownHost hosts "eubackup.kitenet.net" "joey"
+	`requires` Ssh.knownHost hosts "eubackup.kitenet.net" (User "joey")
 	
 tmp :: Property HasInfo
 tmp = propertyList "tmp.kitenet.net" $ props
@@ -366,16 +370,16 @@
 -- Twitter, you kill us.
 twitRss :: Property HasInfo
 twitRss = combineProperties "twitter rss" $ props
-	& Git.cloned "joey" "git://git.kitenet.net/twitrss.git" dir Nothing
+	& Git.cloned (User "joey") "git://git.kitenet.net/twitrss.git" dir Nothing
 	& check (not <$> doesFileExist (dir </> "twitRss")) compiled
 	& feed "http://twitter.com/search/realtime?q=git-annex" "git-annex-twitter"
 	& feed "http://twitter.com/search/realtime?q=olduse+OR+git-annex+OR+debhelper+OR+etckeeper+OR+ikiwiki+-ashley_ikiwiki" "twittergrep"
   where
 	dir = "/srv/web/tmp.kitenet.net/twitrss"
 	crontime = Cron.Times "15 * * * *"
-	feed url desc = Cron.job desc crontime "joey" dir $
+	feed url desc = Cron.job desc crontime (User "joey") dir $
 		"./twitRss " ++ shellEscape url ++ " > " ++ shellEscape ("../" ++ desc ++ ".rss")
-	compiled = userScriptProperty "joey"
+	compiled = userScriptProperty (User "joey")
 		[ "cd " ++ dir
 		, "ghc --make twitRss" 
 		]
@@ -387,26 +391,26 @@
 
 -- Work around for expired ssl cert.
 pumpRss :: Property NoInfo
-pumpRss = Cron.job "pump rss" (Cron.Times "15 * * * *") "joey" "/srv/web/tmp.kitenet.net/"
+pumpRss = Cron.job "pump rss" (Cron.Times "15 * * * *") (User "joey") "/srv/web/tmp.kitenet.net/"
 	"wget https://pump2rss.com/feed/joeyh@identi.ca.atom -O pump.atom.new --no-check-certificate 2>/dev/null; sed 's/ & / /g' pump.atom.new > pump.atom"
 
 ircBouncer :: Property HasInfo
 ircBouncer = propertyList "IRC bouncer" $ props
 	& Apt.installed ["znc"]
-	& User.accountFor "znc"
+	& User.accountFor (User "znc")
 	& File.dirExists (takeDirectory conf)
 	& File.hasPrivContent conf anyContext
-	& File.ownerGroup conf "znc" "znc"
-	& Cron.job "znconboot" (Cron.Times "@reboot") "znc" "~" "znc"
+	& File.ownerGroup conf (User "znc") (Group "znc")
+	& Cron.job "znconboot" (Cron.Times "@reboot") (User "znc") "~" "znc"
 	-- ensure running if it was not already
-	& trivial (userScriptProperty "znc" ["znc || true"])
+	& trivial (userScriptProperty (User "znc") ["znc || true"])
 		`describe` "znc running"
   where
 	conf = "/home/znc/.znc/configs/znc.conf"
 
 kiteShellBox :: Property NoInfo
 kiteShellBox = propertyList "kitenet.net shellinabox"
-	[ Apt.installed ["shellinabox"]
+	[ Apt.installed ["openssl", "shellinabox"]
 	, File.hasContent "/etc/default/shellinabox"
 		[ "# Deployed by propellor"
 		, "SHELLINABOX_DAEMON_START=1"
@@ -421,9 +425,9 @@
 githubBackup = propertyList "github-backup box" $ props
 	& Apt.installed ["github-backup", "moreutils"]
 	& githubKeys
-	& Cron.niceJob "github-backup run" (Cron.Times "30 4 * * *") "joey"
+	& Cron.niceJob "github-backup run" (Cron.Times "30 4 * * *") (User "joey")
 		"/home/joey/lib/backup" backupcmd
-	& Cron.niceJob "gitriddance" (Cron.Times "30 4 * * *") "joey"
+	& Cron.niceJob "gitriddance" (Cron.Times "30 4 * * *") (User "joey")
 		"/home/joey/lib/backup" gitriddancecmd
   where
 	backupcmd = intercalate "&&" $
@@ -442,7 +446,7 @@
 githubKeys = 
 	let f = "/home/joey/.github-keys"
 	in File.hasPrivContent f anyContext
-		`onChange` File.ownerGroup f "joey" "joey"
+		`onChange` File.ownerGroup f (User "joey") (Group "joey")
 
 
 -- these repos are only mirrored on github, I don't want
@@ -456,17 +460,17 @@
 	, ("etckeeper", plzuseurl "http://etckeeper.branchable.com/todo/")
 	]
   where
-	plzuseurl u = "please submit changes to " ++ u ++ " instead of using github pull requests"
+	plzuseurl u = "Please submit changes to " ++ u ++ " instead of using github pull requests, which are not part of my workflow. -- A robot acting on behalf of Joey Hess"
 
 rsyncNetBackup :: [Host] -> Property NoInfo
 rsyncNetBackup hosts = Cron.niceJob "rsync.net copied in daily" (Cron.Times "30 5 * * *")
-	"joey" "/home/joey/lib/backup" "mkdir -p rsync.net && rsync --delete -az 2318@usw-s002.rsync.net: rsync.net"
-	`requires` Ssh.knownHost hosts "usw-s002.rsync.net" "joey"
+	(User "joey") "/home/joey/lib/backup" "mkdir -p rsync.net && rsync --delete -az 2318@usw-s002.rsync.net: rsync.net"
+	`requires` Ssh.knownHost hosts "usw-s002.rsync.net" (User "joey")
 
 backupsBackedupFrom :: [Host] -> HostName -> FilePath -> Property NoInfo
 backupsBackedupFrom hosts srchost destdir = Cron.niceJob desc
-	(Cron.Times "@reboot") "joey" "/" cmd
-	`requires` Ssh.knownHost hosts srchost "joey"
+	(Cron.Times "@reboot") (User "joey") "/" cmd
+	`requires` Ssh.knownHost hosts srchost (User "joey")
   where
 	desc = "backups copied from " ++ srchost ++ " on boot"
 	cmd = "rsync -az --bwlimit=300K --partial --delete " ++ srchost ++ ":lib/backup/ " ++ destdir </> srchost
@@ -479,11 +483,11 @@
 		`requires` mkdir "/home/joey/lib"
 	mkrepo r = mkdir ("/home/joey/lib/backup/" ++ r ++ ".obnam")
 	mkdir d = File.dirExists d
-		`before` File.ownerGroup d "joey" "joey"
+		`before` File.ownerGroup d (User "joey") (Group "joey")
 
 podcatcher :: Property NoInfo
 podcatcher = Cron.niceJob "podcatcher run hourly" (Cron.Times "55 * * * *")
-	"joey" "/home/joey/lib/sound/podcasts"
+	(User "joey") "/home/joey/lib/sound/podcasts"
 	"xargs git-annex importfeed -c annex.genmetadata=true < feeds; mr --quiet update"
 	`requires` Apt.installed ["git-annex", "myrepos"]
 
@@ -641,7 +645,7 @@
 	& File.hasPrivContent dovecotusers ctx
 		`onChange` (dovecotusers `File.mode`
 			combineModes [ownerReadMode, groupReadMode])
-	& File.ownerGroup dovecotusers "root" "dovecot"
+	& File.ownerGroup dovecotusers (User "root") (Group "dovecot")
 
 	& Apt.installed ["mutt", "bsd-mailx", "alpine"]
 
@@ -709,7 +713,7 @@
 		& Apt.serviceInstalledRunning "opendkim"
 		& File.dirExists "/etc/mail"
 		& File.hasPrivContent "/etc/mail/dkim.key" (Context "kitenet.net")
-		& File.ownerGroup "/etc/mail/dkim.key" "opendkim" "opendkim"
+		& File.ownerGroup "/etc/mail/dkim.key" (User "opendkim") (Group "opendkim")
 		& "/etc/default/opendkim" `File.containsLine`
 			"SOCKET=\"inet:8891@localhost\""
 		& "/etc/opendkim.conf" `File.containsLines`
diff --git a/src/Propellor/Property/Ssh.hs b/src/Propellor/Property/Ssh.hs
--- a/src/Propellor/Property/Ssh.hs
+++ b/src/Propellor/Property/Ssh.hs
@@ -54,17 +54,17 @@
 passwordAuthentication :: Bool -> Property NoInfo
 passwordAuthentication = setSshdConfig "PasswordAuthentication"
 
-dotDir :: UserName -> IO FilePath
+dotDir :: User -> IO FilePath
 dotDir user = do
 	h <- homedir user
 	return $ h </> ".ssh"
 
-dotFile :: FilePath -> UserName -> IO FilePath
+dotFile :: FilePath -> User -> IO FilePath
 dotFile f user = do
 	d <- dotDir user
 	return $ d </> f
 
-hasAuthorizedKeys :: UserName -> IO Bool
+hasAuthorizedKeys :: User -> IO Bool
 hasAuthorizedKeys = go <=< dotFile "authorized_keys"
   where
 	go f = not . null <$> catchDefaultIO "" (readFile f)
@@ -151,19 +151,19 @@
 -- PrivData.
 --
 -- If the user already has a private/public key, it is left unchanged.
-keyImported :: IsContext c => SshKeyType -> UserName -> c -> Property HasInfo
+keyImported :: IsContext c => SshKeyType -> User -> c -> Property HasInfo
 keyImported = keyImported' Nothing
 
 -- | A file can be speficied to write the key to somewhere other than
 -- usual. Allows a user to have multiple keys for different roles.
-keyImported' :: IsContext c => Maybe FilePath -> SshKeyType -> UserName -> c -> Property HasInfo
-keyImported' dest keytype user context = combineProperties desc
-	[ installkey (SshPubKey keytype user) (install writeFile ".pub")
-	, installkey (SshPrivKey keytype user) (install writeFileProtected "")
+keyImported' :: IsContext c => Maybe FilePath -> SshKeyType -> User -> c -> Property HasInfo
+keyImported' dest keytype user@(User u) context = combineProperties desc
+	[ installkey (SshPubKey keytype u) (install writeFile ".pub")
+	, installkey (SshPrivKey keytype u) (install writeFileProtected "")
 	]
   where
 	desc = unwords $ catMaybes
-		[ Just user
+		[ Just u
 		, Just "has ssh key"
 		, dest
 		, Just $ "(" ++ fromKeyType keytype ++ ")"
@@ -178,13 +178,13 @@
 				[ property desc $ makeChange $ do
 					createDirectoryIfMissing True (takeDirectory f)
 					writer f key
-				, File.ownerGroup f user user
-				, File.ownerGroup (takeDirectory f) user user
+				, File.ownerGroup f user (userGroup user)
+				, File.ownerGroup (takeDirectory f) user (userGroup user)
 				]
 			)
 	keyfile ext = case dest of
 		Nothing -> do
-			home <- homeDirectory <$> getUserEntryForName user
+			home <- homeDirectory <$> getUserEntryForName u
 			return $ home </> ".ssh" </> "id_" ++ fromKeyType keytype ++ ext
 		Just f -> return $ f ++ ext
 
@@ -196,19 +196,19 @@
 
 -- | Puts some host's ssh public key(s), as set using 'pubKey' or 'hostKey'
 -- into the known_hosts file for a user.
-knownHost :: [Host] -> HostName -> UserName -> Property NoInfo
-knownHost hosts hn user = property desc $
+knownHost :: [Host] -> HostName -> User -> Property NoInfo
+knownHost hosts hn user@(User u) = property desc $
 	go =<< fromHost hosts hn getPubKey
   where
-	desc = user ++ " knows ssh key for " ++ hn
+	desc = u ++ " knows ssh key for " ++ hn
 	go (Just m) | not (M.null m) = do
 		f <- liftIO $ dotFile "known_hosts" user
 		ensureProperty $ combineProperties desc
 			[ File.dirExists (takeDirectory f)
 			, f `File.containsLines`
 				(map (\k -> hn ++ " " ++ k) (M.elems m))
-			, File.ownerGroup f user user
-			, File.ownerGroup (takeDirectory f) user user
+			, File.ownerGroup f user (userGroup user)
+			, File.ownerGroup (takeDirectory f) user (userGroup user)
 			]
 	go _ = do
 		warningMessage $ "no configred pubKey for " ++ hn
@@ -217,32 +217,32 @@
 -- | Makes a user have authorized_keys from the PrivData
 --
 -- This removes any other lines from the file.
-authorizedKeys :: IsContext c => UserName -> c -> Property HasInfo
-authorizedKeys user context = withPrivData (SshAuthorizedKeys user) context $ \get ->
-	property (user ++ " has authorized_keys") $ get $ \v -> do
+authorizedKeys :: IsContext c => User -> c -> Property HasInfo
+authorizedKeys user@(User u) context = withPrivData (SshAuthorizedKeys u) context $ \get ->
+	property (u ++ " has authorized_keys") $ get $ \v -> do
 		f <- liftIO $ dotFile "authorized_keys" user
 		liftIO $ do
 			createDirectoryIfMissing True (takeDirectory f)
 			writeFileProtected f v
 		ensureProperties 
-			[ File.ownerGroup f user user
-			, File.ownerGroup (takeDirectory f) user user
+			[ File.ownerGroup f user (userGroup user)
+			, File.ownerGroup (takeDirectory f) user (userGroup user)
 			] 
 
 -- | Ensures that a user's authorized_keys contains a line.
 -- Any other lines in the file are preserved as-is.
-authorizedKey :: UserName -> String -> Property NoInfo
-authorizedKey user l = property desc $ do
+authorizedKey :: User -> String -> Property NoInfo
+authorizedKey user@(User u) l = property desc $ do
 	f <- liftIO $ dotFile "authorized_keys" user
 	ensureProperty $ combineProperties desc
 		[ f `File.containsLine` l
 			`requires` File.dirExists (takeDirectory f)
 			`onChange` File.mode f (combineModes [ownerWriteMode, ownerReadMode])
-		, File.ownerGroup f user user
-		, File.ownerGroup (takeDirectory f) user user
+		, File.ownerGroup f user (userGroup user)
+		, File.ownerGroup (takeDirectory f) user (userGroup user)
 		]
   where
-	desc = user ++ " has autorized_keys line " ++ l
+	desc = u ++ " has autorized_keys"
 
 -- | Makes the ssh server listen on a given port, in addition to any other
 -- ports it is configured to listen on.
diff --git a/src/Propellor/Property/Sudo.hs b/src/Propellor/Property/Sudo.hs
--- a/src/Propellor/Property/Sudo.hs
+++ b/src/Propellor/Property/Sudo.hs
@@ -9,8 +9,8 @@
 
 -- | Allows a user to sudo. If the user has a password, sudo is configured
 -- to require it. If not, NOPASSWORD is enabled for the user.
-enabledFor :: UserName -> Property NoInfo
-enabledFor user = property desc go `requires` Apt.installed ["sudo"]
+enabledFor :: User -> Property NoInfo
+enabledFor user@(User u) = property desc go `requires` Apt.installed ["sudo"]
   where
 	go = do
 		locked <- liftIO $ isLockedPassword user
@@ -18,8 +18,8 @@
 			fileProperty desc
 				(modify locked . filter (wanted locked))
 				"/etc/sudoers"
-	desc = user ++ " is sudoer"
-	sudobaseline = user ++ " ALL=(ALL:ALL)"
+	desc = u ++ " is sudoer"
+	sudobaseline = u ++ " ALL=(ALL:ALL)"
 	sudoline True = sudobaseline ++ " NOPASSWD:ALL"
 	sudoline False = sudobaseline ++ " ALL"
 	wanted locked l
diff --git a/src/Propellor/Property/Tor.hs b/src/Propellor/Property/Tor.hs
--- a/src/Propellor/Property/Tor.hs
+++ b/src/Propellor/Property/Tor.hs
@@ -52,7 +52,7 @@
 
 torPrivKey :: Context -> Property HasInfo
 torPrivKey context = f `File.hasPrivContent` context
-	`onChange` File.ownerGroup f user user
+	`onChange` File.ownerGroup f user (userGroup user)
 	-- install tor first, so the directory exists with right perms
 	`requires` Apt.installed ["tor"]
   where
@@ -140,8 +140,8 @@
 				writeFileProtected f content
 			, File.mode (takeDirectory f) $ combineModes
 				[ownerReadMode, ownerWriteMode, ownerExecuteMode]
-			, File.ownerGroup (takeDirectory f) user user
-			, File.ownerGroup f user user
+			, File.ownerGroup (takeDirectory f) user (userGroup user)
+			, File.ownerGroup f user (userGroup user)
 			]
 		)
 
@@ -157,8 +157,8 @@
 varRun :: FilePath
 varRun = "/var/run/tor"
 
-user :: UserName
-user = "debian-tor"
+user :: User
+user = User "debian-tor"
 
 type NickName = String
 
diff --git a/src/Propellor/Property/User.hs b/src/Propellor/Property/User.hs
--- a/src/Propellor/Property/User.hs
+++ b/src/Propellor/Property/User.hs
@@ -3,34 +3,35 @@
 import System.Posix
 
 import Propellor
+import qualified Propellor.Property.File as File
 
 data Eep = YesReallyDeleteHome
 
-accountFor :: UserName -> Property NoInfo
-accountFor user = check (isNothing <$> catchMaybeIO (homedir user)) $ cmdProperty "adduser"
+accountFor :: User -> Property NoInfo
+accountFor user@(User u) = check (isNothing <$> catchMaybeIO (homedir user)) $ cmdProperty "adduser"
 	[ "--disabled-password"
 	, "--gecos", ""
-	, user
+	, u
 	]
-	`describe` ("account for " ++ user)
+	`describe` ("account for " ++ u)
 
 -- | Removes user home directory!! Use with caution.
-nuked :: UserName -> Eep -> Property NoInfo
-nuked user _ = check (isJust <$> catchMaybeIO (homedir user)) $ cmdProperty "userdel"
+nuked :: User -> Eep -> Property NoInfo
+nuked user@(User u) _ = check (isJust <$> catchMaybeIO (homedir user)) $ cmdProperty "userdel"
 	[ "-r"
-	, user
+	, u
 	]
-	`describe` ("nuked user " ++ user)
+	`describe` ("nuked user " ++ u)
 
 -- | Only ensures that the user has some password set. It may or may
 -- not be a password from the PrivData.
-hasSomePassword :: UserName -> Property HasInfo
+hasSomePassword :: User -> Property HasInfo
 hasSomePassword user = hasSomePassword' user hostContext
 
 -- | While hasSomePassword uses the name of the host as context,
 -- this allows specifying a different context. This is useful when
 -- you want to use the same password on multiple hosts, for example.
-hasSomePassword' :: IsContext c => UserName -> c -> Property HasInfo
+hasSomePassword' :: IsContext c => User -> c -> Property HasInfo
 hasSomePassword' user context = check ((/= HasPassword) <$> getPasswordStatus user) $
 	hasPassword' user context
 
@@ -40,18 +41,18 @@
 -- A user's password can be stored in the PrivData in either of two forms;
 -- the full cleartext <Password> or a <CryptPassword> hash. The latter
 -- is obviously more secure.
-hasPassword :: UserName -> Property HasInfo
+hasPassword :: User -> Property HasInfo
 hasPassword user = hasPassword' user hostContext
 
-hasPassword' :: IsContext c => UserName -> c -> Property HasInfo
-hasPassword' user context = go `requires` shadowConfig True
+hasPassword' :: IsContext c => User -> c -> Property HasInfo
+hasPassword' (User u) context = go `requires` shadowConfig True
   where
 	go = withSomePrivData srcs context $
-		property (user ++ " has password") . setPassword
+		property (u ++ " has password") . setPassword
 	srcs =
-		[ PrivDataSource (CryptPassword user)
+		[ PrivDataSource (CryptPassword u)
 			"a crypt(3)ed password, which can be generated by, for example: perl -e 'print crypt(shift, q{$6$}.shift)' 'somepassword' 'somesalt'"
-		, PrivDataSource (Password user) ("a password for " ++ user)
+		, PrivDataSource (Password u) ("a password for " ++ u)
 		]
 
 setPassword :: (((PrivDataField, PrivData) -> Propellor Result) -> Propellor Result) -> Propellor Result
@@ -66,32 +67,32 @@
 			hPutStrLn h $ user ++ ":" ++ v
 			hClose h
 
-lockedPassword :: UserName -> Property NoInfo
-lockedPassword user = check (not <$> isLockedPassword user) $ cmdProperty "passwd"
+lockedPassword :: User -> Property NoInfo
+lockedPassword user@(User u) = check (not <$> isLockedPassword user) $ cmdProperty "passwd"
 	[ "--lock"
-	, user
+	, u
 	]
-	`describe` ("locked " ++ user ++ " password")
+	`describe` ("locked " ++ u ++ " password")
 
 data PasswordStatus = NoPassword | LockedPassword | HasPassword
 	deriving (Eq)
 
-getPasswordStatus :: UserName -> IO PasswordStatus
-getPasswordStatus user = parse . words <$> readProcess "passwd" ["-S", user]
+getPasswordStatus :: User -> IO PasswordStatus
+getPasswordStatus (User u) = parse . words <$> readProcess "passwd" ["-S", u]
   where
 	parse (_:"L":_) = LockedPassword
 	parse (_:"NP":_) = NoPassword
 	parse (_:"P":_) = HasPassword
 	parse _ = NoPassword
 
-isLockedPassword :: UserName -> IO Bool
+isLockedPassword :: User -> IO Bool
 isLockedPassword user = (== LockedPassword) <$> getPasswordStatus user
 
-homedir :: UserName -> IO FilePath
-homedir user = homeDirectory <$> getUserEntryForName user
+homedir :: User -> IO FilePath
+homedir (User user) = homeDirectory <$> getUserEntryForName user
 
-hasGroup :: UserName -> GroupName -> Property NoInfo
-hasGroup user group' = check test $ cmdProperty "adduser"
+hasGroup :: User -> Group -> Property NoInfo
+hasGroup (User user) (Group group') = check test $ cmdProperty "adduser"
 	[ user
 	, group'
 	]
@@ -110,3 +111,21 @@
 
 shadowExists :: IO Bool
 shadowExists = doesFileExist "/etc/shadow"
+
+-- | Ensures that a user has a specified login shell, and that the shell
+-- is enabled in /etc/shells.
+hasLoginShell :: User -> FilePath -> Property NoInfo
+hasLoginShell user loginshell = shellSetTo user loginshell `requires` shellEnabled loginshell
+
+shellSetTo :: User -> FilePath -> Property NoInfo
+shellSetTo (User u) loginshell = check needchangeshell $
+	cmdProperty "chsh" ["--shell", loginshell, u]
+		`describe` (u ++ " has login shell " ++ loginshell)
+  where
+	needchangeshell = do
+		currshell <- userShell <$> getUserEntryForName u
+		return (currshell /= loginshell)
+
+-- | Ensures that /etc/shells contains a shell.
+shellEnabled :: FilePath -> Property NoInfo
+shellEnabled loginshell = "/etc/shells" `File.containsLine` loginshell
diff --git a/src/Propellor/Types/CmdLine.hs b/src/Propellor/Types/CmdLine.hs
--- a/src/Propellor/Types/CmdLine.hs
+++ b/src/Propellor/Types/CmdLine.hs
@@ -23,5 +23,6 @@
 	| DockerChain HostName String
 	| ChrootChain HostName FilePath Bool Bool
 	| GitPush Fd Fd
+	| Check
 	deriving (Read, Show, Eq)
 
diff --git a/src/Propellor/Types/OS.hs b/src/Propellor/Types/OS.hs
--- a/src/Propellor/Types/OS.hs
+++ b/src/Propellor/Types/OS.hs
@@ -1,20 +1,19 @@
 module Propellor.Types.OS (
-	HostName,
-	UserName,
-	GroupName,
 	System(..),
 	Distribution(..),
 	DebianSuite(..),
 	isStable,
 	Release,
 	Architecture,
+	HostName,
+	UserName,
+	User(..),
+	Group(..),
+	userGroup,
 ) where
 
 import Network.BSD (HostName)
 
-type UserName = String
-type GroupName = String
-
 -- | High level description of a operating system.
 data System = System Distribution Architecture
 	deriving (Show, Eq)
@@ -25,7 +24,7 @@
 	deriving (Show, Eq)
 
 -- | Debian has several rolling suites, and a number of stable releases,
--- such as Stable "wheezy".
+-- such as Stable "jessie".
 data DebianSuite = Experimental | Unstable | Testing | Stable Release
 	deriving (Show, Eq)
 
@@ -35,3 +34,11 @@
 
 type Release = String
 type Architecture = String
+
+type UserName = String
+newtype User = User UserName
+newtype Group = Group String
+
+-- | Makes a Group with the same name as the User.
+userGroup :: User -> Group
+userGroup (User u) = Group u
diff --git a/src/Propellor/Types/PrivData.hs b/src/Propellor/Types/PrivData.hs
--- a/src/Propellor/Types/PrivData.hs
+++ b/src/Propellor/Types/PrivData.hs
@@ -2,8 +2,8 @@
 
 import Propellor.Types.OS
 
--- | Note that removing or changing constructors will break the
--- serialized privdata files, so don't do that!
+-- | Note that removing or changing constructors or changing types will
+-- break the serialized privdata files, so don't do that!
 -- It's fine to add new constructors.
 data PrivDataField
 	= DockerAuthentication
diff --git a/src/config.hs b/src/config.hs
--- a/src/config.hs
+++ b/src/config.hs
@@ -28,7 +28,7 @@
 		& Apt.unattendedUpgrades
 		& Apt.installed ["etckeeper"]
 		& Apt.installed ["ssh"]
-		& User.hasSomePassword "root"
+		& User.hasSomePassword (User "root")
 		& Network.ipv6to4
 		& File.dirExists "/var/www"
 		& Docker.docked webserverContainer
@@ -41,8 +41,8 @@
 
 -- A generic webserver in a Docker container.
 webserverContainer :: Docker.Container
-webserverContainer = Docker.container "webserver" "joeyh/debian-stable"
-	& os (System (Debian (Stable "wheezy")) "amd64")
+webserverContainer = Docker.container "webserver" "debian"
+	& os (System (Debian (Stable "jessie")) "amd64")
 	& Apt.stdSourcesList
 	& Docker.publish "80:80"
 	& Docker.volume "/var/www:/var/www"
diff --git a/src/wrapper.hs b/src/wrapper.hs
--- a/src/wrapper.hs
+++ b/src/wrapper.hs
@@ -77,7 +77,7 @@
 			, void $ boolSystem "git" [Param "clone", Param netrepo, File propellordir]
 			)
 
-	checkRepo = whenM (doesFileExist disthead) $ do
+	checkRepo = whenM (doesFileExist disthead <&&> doesFileExist (propellordir </> "propellor.cabal")) $ do
 		headrev <- takeWhile (/= '\n') <$> readFile disthead
 		changeWorkingDirectory propellordir
 		headknown <- catchMaybeIO $