From b8b746a7f1bdbf179136959a85138fde60c43588 Mon Sep 17 00:00:00 2001
From: Joey Hess <joey@kitenet.net>
Date: Thu, 20 Nov 2014 14:06:55 -0400
Subject: starting work on a Chroot module

factored out info up-propigation code rom Docker
---
 src/Propellor/Property/Chroot.hs | 57 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 src/Propellor/Property/Chroot.hs

(limited to 'src/Propellor/Property/Chroot.hs')

diff --git a/src/Propellor/Property/Chroot.hs b/src/Propellor/Property/Chroot.hs
new file mode 100644
index 00000000..e5046937
--- /dev/null
+++ b/src/Propellor/Property/Chroot.hs
@@ -0,0 +1,57 @@
+module Propellor.Property.Chroot (
+	Chroot,
+	chroot,
+	provisioned,
+) where
+
+import Propellor
+import qualified Propellor.Property.Debootstrap as Debootstrap
+
+import qualified Data.Map as M
+
+data Chroot = Chroot FilePath System Host
+
+instance Hostlike Chroot where
+	(Chroot l s h) & p = Chroot l s (h & p)
+	(Chroot l s h) &^ p = Chroot l s (h &^ p)
+	getHost (Chroot _ _ h) = h
+
+-- | Defines a Chroot at the given location, containing the specified
+-- System. Properties can be added to configure the Chroot.
+--
+-- > chroot "/srv/chroot/ghc-dev" (System (Debian Unstable) "amd64"
+-- >    & Apt.installed ["build-essential", "ghc", "haskell-platform"]
+-- >	& ...
+chroot :: FilePath -> System -> Chroot
+chroot location system = Chroot location system (Host location [] mempty)
+
+-- | Ensures that the chroot exists and is provisioned according to its
+-- properties.
+--
+-- Reverting this property removes the chroot. Note that it does not ensure
+-- that any processes that might be running inside the chroot are stopped.
+provisioned :: Chroot -> RevertableProperty
+provisioned c@(Chroot loc system _) = RevertableProperty
+	(propigateChrootInfo c (go "exists" setup))
+	(go "removed" teardown)
+  where
+	go desc a = property ("chroot " ++ loc ++ " " ++ desc) $ do
+		ensureProperties [a]
+
+	setup = provisionChroot c `requires` built
+	
+	built = case system of
+		(System (Debian _) _) -> debootstrap
+		(System (Ubuntu _) _) -> debootstrap
+
+	debootstrap = unrevertable (Debootstrap.built loc system [])
+
+	teardown = undefined
+
+propigateChrootInfo :: Chroot -> Property -> Property
+propigateChrootInfo c@(Chroot loc _ h) p = propigateInfo c p (<> chrootinfo)
+  where
+	chrootinfo = mempty $ mempty { _chroots = M.singleton loc h }
+
+provisionChroot :: Chroot -> Property
+provisionChroot = undefined
-- 
cgit v1.3-2-g0d8e


From a4f04fcb02d76d9903c5bbc65827565bad6c2d8c Mon Sep 17 00:00:00 2001
From: Joey Hess <joey@kitenet.net>
Date: Thu, 20 Nov 2014 15:15:28 -0400
Subject: propellor spin

---
 propellor.cabal                       |  2 +-
 src/Propellor/CmdLine.hs              |  6 ++-
 src/Propellor/Engine.hs               | 18 +++++++++
 src/Propellor/Property/Chroot.hs      | 76 +++++++++++++++++++++++++++++++++--
 src/Propellor/Property/Docker.hs      | 14 +------
 src/Propellor/Property/Docker/Shim.hs | 61 ----------------------------
 src/Propellor/Shim.hs                 | 62 ++++++++++++++++++++++++++++
 src/Propellor/Types.hs                |  1 +
 8 files changed, 161 insertions(+), 79 deletions(-)
 delete mode 100644 src/Propellor/Property/Docker/Shim.hs
 create mode 100644 src/Propellor/Shim.hs

(limited to 'src/Propellor/Property/Chroot.hs')

diff --git a/propellor.cabal b/propellor.cabal
index 7f2b2376..23708fd2 100644
--- a/propellor.cabal
+++ b/propellor.cabal
@@ -121,7 +121,7 @@ Library
     Propellor.Ssh
     Propellor.PrivData.Paths
     Propellor.Protocol
-    Propellor.Property.Docker.Shim
+    Propellor.Shim
     Utility.Applicative
     Utility.Data
     Utility.Directory
diff --git a/src/Propellor/CmdLine.hs b/src/Propellor/CmdLine.hs
index 061c9700..466b60f5 100644
--- a/src/Propellor/CmdLine.hs
+++ b/src/Propellor/CmdLine.hs
@@ -15,7 +15,8 @@ import Propellor.Git
 import Propellor.Ssh
 import Propellor.Server
 import qualified Propellor.Property.Docker as Docker
-import qualified Propellor.Property.Docker.Shim as DockerShim
+import qualified Propellor.Property.Chroot as Chroot
+import qualified Propellor.Shim as Shim
 import Utility.SafeCommand
 
 usage :: Handle -> IO ()
@@ -72,7 +73,7 @@ processCmdLine = go =<< getArgs
 -- | Runs propellor on hosts, as controlled by command-line options.
 defaultMain :: [Host] -> IO ()
 defaultMain hostlist = do
-	DockerShim.cleanEnv
+	Shim.cleanEnv
 	checkDebugMode
 	cmdline <- processCmdLine
 	debug ["command line: ", show cmdline]
@@ -85,6 +86,7 @@ defaultMain hostlist = do
 	go _ ListFields = listPrivDataFields hostlist
 	go _ (AddKey keyid) = addKey keyid
 	go _ (DockerChain hn cid) = Docker.chain hostlist hn cid
+	go _ (ChrootChain hn loc) = Chroot.chain hostlist hn loc
 	go _ (DockerInit hn) = Docker.init hn
 	go _ (GitPush fin fout) = gitPushHelper fin fout
 	go _ (Update _) = forceConsole >> fetchFirst (onlyprocess update)
diff --git a/src/Propellor/Engine.hs b/src/Propellor/Engine.hs
index 3fa9ffc0..0cbf6247 100644
--- a/src/Propellor/Engine.hs
+++ b/src/Propellor/Engine.hs
@@ -11,12 +11,15 @@ import "mtl" Control.Monad.Reader
 import Control.Exception (bracket)
 import System.PosixCompat
 import System.Posix.IO
+import Data.Maybe
 
 import Propellor.Types
 import Propellor.Message
 import Propellor.Exception
 import Propellor.Info
 import Utility.Exception
+import Utility.PartialPrelude
+import Utility.Monad
 
 runPropellor :: Host -> Propellor a -> IO a
 runPropellor host a = runReaderT (runWithHost a) host
@@ -62,3 +65,18 @@ onlyProcess lockfile a = bracket lock unlock (const a)
 		return l
 	unlock = closeFd
 	alreadyrunning = error "Propellor is already running on this host!"
+
+-- | Reads and displays each line from the Handle, except for the last line
+-- which is a Result.
+processChainOutput :: Handle -> IO Result
+processChainOutput h = go Nothing
+  where
+	go lastline = do
+		v <- catchMaybeIO (hGetLine h)
+		case v of
+			Nothing -> pure $ fromMaybe FailedChange $
+				readish =<< lastline
+			Just s -> do
+				maybe noop putStrLn lastline
+				hFlush stdout
+				go (Just s)
diff --git a/src/Propellor/Property/Chroot.hs b/src/Propellor/Property/Chroot.hs
index e5046937..38e09b52 100644
--- a/src/Propellor/Property/Chroot.hs
+++ b/src/Propellor/Property/Chroot.hs
@@ -2,12 +2,17 @@ module Propellor.Property.Chroot (
 	Chroot,
 	chroot,
 	provisioned,
+	chain,
 ) where
 
 import Propellor
 import qualified Propellor.Property.Debootstrap as Debootstrap
+import qualified Propellor.Shim as Shim
+import Utility.SafeCommand
 
 import qualified Data.Map as M
+import Data.List.Utils
+import System.Posix.Directory
 
 data Chroot = Chroot FilePath System Host
 
@@ -35,8 +40,7 @@ provisioned c@(Chroot loc system _) = RevertableProperty
 	(propigateChrootInfo c (go "exists" setup))
 	(go "removed" teardown)
   where
-	go desc a = property ("chroot " ++ loc ++ " " ++ desc) $ do
-		ensureProperties [a]
+	go desc a = property (chrootDesc c desc) $ ensureProperties [a]
 
 	setup = provisionChroot c `requires` built
 	
@@ -53,5 +57,71 @@ propigateChrootInfo c@(Chroot loc _ h) p = propigateInfo c p (<> chrootinfo)
   where
 	chrootinfo = mempty $ mempty { _chroots = M.singleton loc h }
 
+-- | Propellor is run inside the chroot to provision it.
+--
+-- Strange and wonderful tricks let the host's /usr/local/propellor
+-- be used inside the chroot, without needing to install anything.
 provisionChroot :: Chroot -> Property
-provisionChroot = undefined
+provisionChroot c@(Chroot loc _ _) = property (chrootDesc c "provisioned") $ do
+	let d = localdir </> shimdir c
+	let me = localdir </> "propellor"
+	shim <- liftIO $ ifM (doesDirectoryExist d)
+		( pure (Shim.file me d)
+		, Shim.setup me d
+		)
+	ifM (liftIO $ bindmount shim)
+		( chainprovision shim
+		, return FailedChange
+		)
+  where
+	bindmount shim = ifM (doesFileExist (loc ++ shim))
+		( return True
+		, do
+			let mntpnt = loc ++ localdir
+			createDirectoryIfMissing True mntpnt
+			boolSystem "mount"
+				[ Param "--bind"
+				, File localdir, File mntpnt
+				]
+		)
+	
+	chainprovision shim = do
+		parenthost <- asks hostName
+		let p = inChrootProcess c
+			[ shim
+			, "--continue"
+			, show $ toChain parenthost c
+			]
+		liftIO $ withHandle StdoutHandle createProcessSuccess p
+			processChainOutput
+
+toChain :: HostName -> Chroot -> CmdLine
+toChain parenthost (Chroot loc _ _) = ChrootChain parenthost loc
+
+chain :: [Host] -> HostName -> FilePath -> IO ()
+chain hostlist hn loc = case findHostNoAlias hostlist hn of
+	Nothing -> errorMessage ("cannot find host " ++ hn)
+	Just parenthost -> case M.lookup loc (_chroots $ _chrootinfo $ hostInfo parenthost) of
+		Nothing -> errorMessage ("cannot find chroot " ++ loc ++ " on host " ++ hn)
+		Just h -> go h
+  where
+	go h = do
+		changeWorkingDirectory localdir
+		onlyProcess (provisioningLock loc) $ do
+			r <- runPropellor h $ ensureProperties $ hostProperties h
+			putStrLn $ "\n" ++ show r
+
+inChrootProcess :: Chroot -> [String] -> CreateProcess
+inChrootProcess (Chroot loc _ _) cmd = proc "chroot" (loc:cmd)
+
+provisioningLock :: FilePath -> FilePath
+provisioningLock containerloc = "chroot" </> mungeloc containerloc ++ ".lock"
+
+shimdir :: Chroot -> FilePath
+shimdir (Chroot loc _ _) = "chroot" </> mungeloc loc ++ ".shim"
+
+mungeloc :: FilePath -> String
+mungeloc = replace "/" "_"
+
+chrootDesc :: Chroot -> String -> String
+chrootDesc (Chroot loc _ _) desc = "chroot " ++ loc ++ " " ++ desc
diff --git a/src/Propellor/Property/Docker.hs b/src/Propellor/Property/Docker.hs
index 92cc124a..5cf60ff9 100644
--- a/src/Propellor/Property/Docker.hs
+++ b/src/Propellor/Property/Docker.hs
@@ -41,7 +41,7 @@ module Propellor.Property.Docker (
 import Propellor hiding (init)
 import qualified Propellor.Property.File as File
 import qualified Propellor.Property.Apt as Apt
-import qualified Propellor.Property.Docker.Shim as Shim
+import qualified Propellor.Shim as Shim
 import Utility.SafeCommand
 import Utility.Path
 import Utility.ThreadScheduler
@@ -432,20 +432,10 @@ provisionContainer cid = containerDesc cid $ property "provisioned" $ liftIO $ d
 		[ if isConsole msgh then "-it" else "-i" ]
 		(shim : params)
 	r <- withHandle StdoutHandle createProcessSuccess p $
-		processoutput Nothing
+		processChainOutput
 	when (r /= FailedChange) $
 		setProvisionedFlag cid 
 	return r
-  where
-	processoutput lastline h = do
-		v <- catchMaybeIO (hGetLine h)
-		case v of
-			Nothing -> pure $ fromMaybe FailedChange $
-				readish =<< lastline
-			Just s -> do
-				maybe noop putStrLn lastline
-				hFlush stdout
-				processoutput (Just s) h
 
 toChain :: ContainerId -> CmdLine
 toChain cid = DockerChain (containerHostName cid) (fromContainerId cid)
diff --git a/src/Propellor/Property/Docker/Shim.hs b/src/Propellor/Property/Docker/Shim.hs
deleted file mode 100644
index c2f35d0c..00000000
--- a/src/Propellor/Property/Docker/Shim.hs
+++ /dev/null
@@ -1,61 +0,0 @@
--- | Support for running propellor, as built outside a docker container,
--- inside the container.
---
--- Note: This is currently Debian specific, due to glibcLibs.
-
-module Propellor.Property.Docker.Shim (setup, cleanEnv, file) where
-
-import Propellor
-import Utility.LinuxMkLibs
-import Utility.SafeCommand
-import Utility.Path
-import Utility.FileMode
-
-import Data.List
-import System.Posix.Files
-
--- | Sets up a shimmed version of the program, in a directory, and
--- returns its path.
-setup :: FilePath -> FilePath -> IO FilePath
-setup propellorbin dest = do
-	createDirectoryIfMissing True dest
-
-	libs <- parseLdd <$> readProcess "ldd" [propellorbin]
-	glibclibs <- glibcLibs
-	let libs' = nub $ libs ++ glibclibs
-	libdirs <- map (dest ++) . nub . catMaybes
-		<$> mapM (installLib installFile dest) libs'
-	
-	let linker = (dest ++) $ 
-		fromMaybe (error "cannot find ld-linux linker") $
-			headMaybe $ filter ("ld-linux" `isInfixOf`) libs'
-	let gconvdir = (dest ++) $ parentDir $
-		fromMaybe (error "cannot find gconv directory") $
-			headMaybe $ filter ("/gconv/" `isInfixOf`) glibclibs
-	let linkerparams = ["--library-path", intercalate ":" libdirs ]
-	let shim = file propellorbin dest
-	writeFile shim $ unlines
-		[ "#!/bin/sh"
-		, "GCONV_PATH=" ++ shellEscape gconvdir
-		, "export GCONV_PATH"
-		, "exec " ++ unwords (map shellEscape $ linker : linkerparams) ++ 
-			" " ++ shellEscape propellorbin ++ " \"$@\""
-		]
-	modifyFileMode shim (addModes executeModes)
-	return shim
-
-cleanEnv :: IO ()
-cleanEnv = void $ unsetEnv "GCONV_PATH"
-
-file :: FilePath -> FilePath -> FilePath
-file propellorbin dest = dest </> takeFileName propellorbin
-
-installFile :: FilePath -> FilePath -> IO ()
-installFile top f = do
-	createDirectoryIfMissing True destdir
-	nukeFile dest
-	createLink f dest `catchIO` (const copy)
-  where
-	copy = void $ boolSystem "cp" [Param "-a", Param f, Param dest]
-	destdir = inTop top $ parentDir f
-	dest = inTop top f
diff --git a/src/Propellor/Shim.hs b/src/Propellor/Shim.hs
new file mode 100644
index 00000000..5b5aa68e
--- /dev/null
+++ b/src/Propellor/Shim.hs
@@ -0,0 +1,62 @@
+-- | Support for running propellor, as built outside a container,
+-- inside the container, without needing to install anything into the
+-- container.
+--
+-- Note: This is currently Debian specific, due to glibcLibs.
+
+module Propellor.Shim (setup, cleanEnv, file) where
+
+import Propellor
+import Utility.LinuxMkLibs
+import Utility.SafeCommand
+import Utility.Path
+import Utility.FileMode
+
+import Data.List
+import System.Posix.Files
+
+-- | Sets up a shimmed version of the program, in a directory, and
+-- returns its path.
+setup :: FilePath -> FilePath -> IO FilePath
+setup propellorbin dest = do
+	createDirectoryIfMissing True dest
+
+	libs <- parseLdd <$> readProcess "ldd" [propellorbin]
+	glibclibs <- glibcLibs
+	let libs' = nub $ libs ++ glibclibs
+	libdirs <- map (dest ++) . nub . catMaybes
+		<$> mapM (installLib installFile dest) libs'
+	
+	let linker = (dest ++) $ 
+		fromMaybe (error "cannot find ld-linux linker") $
+			headMaybe $ filter ("ld-linux" `isInfixOf`) libs'
+	let gconvdir = (dest ++) $ parentDir $
+		fromMaybe (error "cannot find gconv directory") $
+			headMaybe $ filter ("/gconv/" `isInfixOf`) glibclibs
+	let linkerparams = ["--library-path", intercalate ":" libdirs ]
+	let shim = file propellorbin dest
+	writeFile shim $ unlines
+		[ "#!/bin/sh"
+		, "GCONV_PATH=" ++ shellEscape gconvdir
+		, "export GCONV_PATH"
+		, "exec " ++ unwords (map shellEscape $ linker : linkerparams) ++ 
+			" " ++ shellEscape propellorbin ++ " \"$@\""
+		]
+	modifyFileMode shim (addModes executeModes)
+	return shim
+
+cleanEnv :: IO ()
+cleanEnv = void $ unsetEnv "GCONV_PATH"
+
+file :: FilePath -> FilePath -> FilePath
+file propellorbin dest = dest </> takeFileName propellorbin
+
+installFile :: FilePath -> FilePath -> IO ()
+installFile top f = do
+	createDirectoryIfMissing True destdir
+	nukeFile dest
+	createLink f dest `catchIO` (const copy)
+  where
+	copy = void $ boolSystem "cp" [Param "-a", Param f, Param dest]
+	destdir = inTop top $ parentDir f
+	dest = inTop top f
diff --git a/src/Propellor/Types.hs b/src/Propellor/Types.hs
index 16ddcc7d..56eafc6d 100644
--- a/src/Propellor/Types.hs
+++ b/src/Propellor/Types.hs
@@ -155,6 +155,7 @@ data CmdLine
 	| Update HostName
 	| DockerInit HostName
 	| DockerChain HostName String
+	| ChrootChain HostName FilePath
 	| GitPush Fd Fd
 	deriving (Read, Show, Eq)
 
-- 
cgit v1.3-2-g0d8e


From 2293b46bf714ca5675515496c041952310b7bae2 Mon Sep 17 00:00:00 2001
From: Joey Hess <joey@kitenet.net>
Date: Thu, 20 Nov 2014 16:04:48 -0400
Subject: fix chroot info propigation

---
 debian/changelog                 | 1 +
 src/Propellor/Property/Chroot.hs | 8 +++++---
 2 files changed, 6 insertions(+), 3 deletions(-)

(limited to 'src/Propellor/Property/Chroot.hs')

diff --git a/debian/changelog b/debian/changelog
index 155d5124..e36e151e 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -19,6 +19,7 @@ propellor (1.0.0) UNRELEASED; urgency=medium
     in the main host list, and are instead passed to
     Docker.docked. (API change)
   * Added support for using debootstrap from propellor.
+  * Propellor can now be used to provision chroots.
 
  -- Joey Hess <id@joeyh.name>  Mon, 10 Nov 2014 11:15:27 -0400
 
diff --git a/src/Propellor/Property/Chroot.hs b/src/Propellor/Property/Chroot.hs
index 38e09b52..9ce9ddaf 100644
--- a/src/Propellor/Property/Chroot.hs
+++ b/src/Propellor/Property/Chroot.hs
@@ -53,9 +53,11 @@ provisioned c@(Chroot loc system _) = RevertableProperty
 	teardown = undefined
 
 propigateChrootInfo :: Chroot -> Property -> Property
-propigateChrootInfo c@(Chroot loc _ h) p = propigateInfo c p (<> chrootinfo)
-  where
-	chrootinfo = mempty $ mempty { _chroots = M.singleton loc h }
+propigateChrootInfo c p = propigateInfo c p (<> chrootInfo c)
+
+chrootInfo :: Chroot -> Info
+chrootInfo (Chroot loc _ h) =
+	mempty { _chrootinfo = mempty { _chroots = M.singleton loc h } }
 
 -- | Propellor is run inside the chroot to provision it.
 --
-- 
cgit v1.3-2-g0d8e


From 3669bd61d0e15682ce25b9a82788b8d69f87d123 Mon Sep 17 00:00:00 2001
From: Joey Hess <joey@kitenet.net>
Date: Thu, 20 Nov 2014 16:07:57 -0400
Subject: propellor spin

---
 src/Propellor/Engine.hs          | 2 +-
 src/Propellor/Property/Chroot.hs | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

(limited to 'src/Propellor/Property/Chroot.hs')

diff --git a/src/Propellor/Engine.hs b/src/Propellor/Engine.hs
index 0cbf6247..969769ce 100644
--- a/src/Propellor/Engine.hs
+++ b/src/Propellor/Engine.hs
@@ -77,6 +77,6 @@ processChainOutput h = go Nothing
 			Nothing -> pure $ fromMaybe FailedChange $
 				readish =<< lastline
 			Just s -> do
-				maybe noop putStrLn lastline
+				maybe noop (\l -> unless (null l) (putStrLn l)) lastline
 				hFlush stdout
 				go (Just s)
diff --git a/src/Propellor/Property/Chroot.hs b/src/Propellor/Property/Chroot.hs
index 9ce9ddaf..ba7bf96c 100644
--- a/src/Propellor/Property/Chroot.hs
+++ b/src/Propellor/Property/Chroot.hs
@@ -109,6 +109,7 @@ chain hostlist hn loc = case findHostNoAlias hostlist hn of
   where
 	go h = do
 		changeWorkingDirectory localdir
+		forceConsole
 		onlyProcess (provisioningLock loc) $ do
 			r <- runPropellor h $ ensureProperties $ hostProperties h
 			putStrLn $ "\n" ++ show r
-- 
cgit v1.3-2-g0d8e


From f9cc7c149ead60d1178fa3b480282f6089cf79bd Mon Sep 17 00:00:00 2001
From: Joey Hess <joey@kitenet.net>
Date: Thu, 20 Nov 2014 17:18:26 -0400
Subject: incomplete systemd container support

---
 debian/changelog                      |   2 +
 propellor.cabal                       |   1 +
 src/Propellor/Property.hs             |   4 --
 src/Propellor/Property/Chroot.hs      |   6 +-
 src/Propellor/Property/Debootstrap.hs |   2 +-
 src/Propellor/Property/Systemd.hs     | 103 ++++++++++++++++++++++++++++++++++
 6 files changed, 110 insertions(+), 8 deletions(-)
 create mode 100644 src/Propellor/Property/Systemd.hs

(limited to 'src/Propellor/Property/Chroot.hs')

diff --git a/debian/changelog b/debian/changelog
index e36e151e..d6dc6155 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -20,6 +20,8 @@ propellor (1.0.0) UNRELEASED; urgency=medium
     Docker.docked. (API change)
   * Added support for using debootstrap from propellor.
   * Propellor can now be used to provision chroots.
+  * systemd-nspawn containers can now be managed by propellor, very similar
+    to its handling of docker containers.
 
  -- Joey Hess <id@joeyh.name>  Mon, 10 Nov 2014 11:15:27 -0400
 
diff --git a/propellor.cabal b/propellor.cabal
index 23708fd2..f45900cf 100644
--- a/propellor.cabal
+++ b/propellor.cabal
@@ -95,6 +95,7 @@ Library
     Propellor.Property.Service
     Propellor.Property.Ssh
     Propellor.Property.Sudo
+    Propellor.Property.Systemd
     Propellor.Property.Tor
     Propellor.Property.User
     Propellor.Property.HostingProvider.CloudAtCost
diff --git a/src/Propellor/Property.hs b/src/Propellor/Property.hs
index 1d750a78..6ace5e4e 100644
--- a/src/Propellor/Property.hs
+++ b/src/Propellor/Property.hs
@@ -131,10 +131,6 @@ boolProperty desc a = property desc $ ifM (liftIO a)
 revert :: RevertableProperty -> RevertableProperty
 revert (RevertableProperty p1 p2) = RevertableProperty p2 p1
 
--- | Turns a revertable property into a regular property.
-unrevertable :: RevertableProperty -> Property
-unrevertable (RevertableProperty p1 _p2) = p1
-
 -- Changes the action that is performed to satisfy a property. 
 adjustProperty :: Property -> (Propellor Result -> Propellor Result) -> Property
 adjustProperty p f = p { propertySatisfy = f (propertySatisfy p) }
diff --git a/src/Propellor/Property/Chroot.hs b/src/Propellor/Property/Chroot.hs
index ba7bf96c..798330b0 100644
--- a/src/Propellor/Property/Chroot.hs
+++ b/src/Propellor/Property/Chroot.hs
@@ -1,5 +1,5 @@
 module Propellor.Property.Chroot (
-	Chroot,
+	Chroot(..),
 	chroot,
 	provisioned,
 	chain,
@@ -24,7 +24,7 @@ instance Hostlike Chroot where
 -- | Defines a Chroot at the given location, containing the specified
 -- System. Properties can be added to configure the Chroot.
 --
--- > chroot "/srv/chroot/ghc-dev" (System (Debian Unstable) "amd64"
+-- > chroot "/srv/chroot/ghc-dev" (System (Debian Unstable) "amd64")
 -- >    & Apt.installed ["build-essential", "ghc", "haskell-platform"]
 -- >	& ...
 chroot :: FilePath -> System -> Chroot
@@ -48,7 +48,7 @@ provisioned c@(Chroot loc system _) = RevertableProperty
 		(System (Debian _) _) -> debootstrap
 		(System (Ubuntu _) _) -> debootstrap
 
-	debootstrap = unrevertable (Debootstrap.built loc system [])
+	debootstrap = toProp (Debootstrap.built loc system [])
 
 	teardown = undefined
 
diff --git a/src/Propellor/Property/Debootstrap.hs b/src/Propellor/Property/Debootstrap.hs
index 4e7bc740..5f521c32 100644
--- a/src/Propellor/Property/Debootstrap.hs
+++ b/src/Propellor/Property/Debootstrap.hs
@@ -33,7 +33,7 @@ built target system@(System _ arch) extraparams =
 	RevertableProperty setup teardown
   where
 	setup = check (unpopulated target <||> ispartial) setupprop
-		`requires` unrevertable installed
+		`requires` toProp installed
 	
 	teardown = check (not <$> unpopulated target) teardownprop
 	
diff --git a/src/Propellor/Property/Systemd.hs b/src/Propellor/Property/Systemd.hs
new file mode 100644
index 00000000..be08a847
--- /dev/null
+++ b/src/Propellor/Property/Systemd.hs
@@ -0,0 +1,103 @@
+module Propellor.Property.Systemd (
+	installed,
+	persistentJournal,
+	container,
+	nspawned,
+) where
+
+import Propellor
+import qualified Propellor.Property.Chroot as Chroot
+import qualified Propellor.Property.Apt as Apt
+import Utility.SafeCommand
+
+import Data.List.Utils
+
+type MachineName = String
+
+type NspawnParam = CommandParam
+
+data Container = Container MachineName System [CommandParam] Host
+
+instance Hostlike Container where
+        (Container n s ps h) & p = Container n s ps (h & p)
+        (Container n s ps h) &^ p = Container n s ps (h &^ p)
+        getHost (Container _ _ _ h) = h
+
+-- dbus is only a Recommends of systemd, but is needed for communication
+-- from the systemd inside a container to the one outside, so make sure it
+-- gets installed.
+installed :: Property
+installed = Apt.installed ["systemd", "dbus"]
+
+-- | Sets up persistent storage of the journal.
+persistentJournal :: Property
+persistentJournal = check (not <$> doesDirectoryExist dir) $ 
+	combineProperties "persistent systetemd journal"
+		[ cmdProperty "install" ["-d", "-g", "systemd-journal", dir]
+		, cmdProperty "setfacl" ["-R", "-nm", "g:adm:rx,d:g:adm:rx", dir]
+		]
+		`requires` Apt.installed ["acl"]
+  where
+	dir = "/var/log/journal"
+
+-- | Defines a container with a given machine name, containing the specified
+-- System. Properties can be added to configure the Container.
+--
+-- > container "webserver" (System (Debian Unstable) "amd64") []
+container :: MachineName -> System -> [NspawnParam] -> Container
+container name system ps = Container name system ps (Host name [] mempty)
+
+-- | Runs a container using systemd-nspawn.
+--
+-- A systemd unit is set up for the container, so it will automatically
+-- be started on boot.
+--
+-- Systemd is automatically installed inside the container, and will
+-- communicate with the host's systemd. This allows systemctl to be used to
+-- examine the status of services running inside the container.
+--
+-- When the host system has persistentJournal enabled, journactl can be
+-- used to examine logs forwarded from the container.
+--
+-- Reverting this property stops the container, removes the systemd unit,
+-- and deletes the chroot and all its contents.
+nspawned :: Container -> RevertableProperty
+nspawned c@(Container name system _ h) = RevertableProperty setup teardown
+  where
+	-- TODO after container is running, use nsenter to enter it
+	-- and run propellor to finish provisioning.
+	setup = toProp (nspawnService c)
+		`requires` toProp chrootprovisioned
+
+	teardown = toProp (revert (chrootprovisioned))
+		`requires` toProp (revert (nspawnService c))
+
+	-- When provisioning the chroot, pass a version of the Host
+	-- that only has the Property of systemd being installed.
+	-- This is to avoid starting any daemons in the chroot,
+	-- which would not run in the container's namespace.
+	chrootprovisioned = Chroot.provisioned $
+		Chroot.Chroot (containerDir name) system $
+			h { hostProperties = [installed] }
+
+nspawnService :: Container -> RevertableProperty
+nspawnService (Container name _ ps _) = RevertableProperty setup teardown
+  where
+	service = nspawnServiceName name
+	servicefile = "/etc/systemd/system/multi-user.target.wants" </> service
+
+	setup = check (not <$> doesFileExist servicefile) $
+		combineProperties ("container running " ++ service)
+			[ cmdProperty "systemctl" ["enable", service]
+			, cmdProperty "systemctl" ["start", service]
+			]
+
+	-- TODO adjust execStart line to reflect ps
+
+	teardown = undefined
+
+nspawnServiceName :: MachineName -> String
+nspawnServiceName name = "systemd-nspawn@" ++ name ++ ".service"
+
+containerDir :: MachineName -> FilePath
+containerDir name = "/var/lib/container" ++ replace "/" "_" name
-- 
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