diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,18 @@
+propellor (0.4.0) unstable; urgency=medium
+
+  * Propellor can configure primary DNS servers, including generating
+    zone files, which is done by looking at the properties of hosts
+    in a domain.
+  * The `cname` property was renamed to `alias` as it does not always
+    generate CNAME in the DNS.
+  * Constructor of Property has changed (use `property` function instead).
+  * All Property combinators now combine together their Attr settings.
+    So Attr settings can be made inside a propertyList, for example.
+  * Run all cron jobs under chronic from moreutils to avoid unnecessary
+    mails.
+
+ -- Joey Hess <joeyh@debian.org>  Sat, 19 Apr 2014 02:09:56 -0400
+
 propellor (0.3.1) unstable; urgency=medium
 
   * Merge scheduler bug fix from git-annex.
diff --git a/Propellor/Attr.hs b/Propellor/Attr.hs
--- a/Propellor/Attr.hs
+++ b/Propellor/Attr.hs
@@ -8,38 +8,65 @@
 import "mtl" Control.Monad.Reader
 import qualified Data.Set as S
 import qualified Data.Map as M
+import Data.Maybe
 import Control.Applicative
 
-pureAttrProperty :: Desc -> (Attr -> Attr) -> AttrProperty 
-pureAttrProperty desc = AttrProperty $ Property ("has " ++ desc)
-	(return NoChange)
+pureAttrProperty :: Desc -> SetAttr -> Property 
+pureAttrProperty desc = Property ("has " ++ desc) (return NoChange)
 
-hostname :: HostName -> AttrProperty
+hostname :: HostName -> Property
 hostname name = pureAttrProperty ("hostname " ++ name) $
 	\d -> d { _hostname = name }
 
 getHostName :: Propellor HostName
 getHostName = asks _hostname
 
-os :: System -> AttrProperty
+os :: System -> Property
 os system = pureAttrProperty ("Operating " ++ show system) $
 	\d -> d { _os = Just system }
 
 getOS :: Propellor (Maybe System)
 getOS = asks _os
 
-cname :: Domain -> AttrProperty
-cname domain = pureAttrProperty ("cname " ++ domain) (addCName domain)
+-- | Indidate that a host has an A record in the DNS.
+--
+-- TODO check at run time if the host really has this address.
+-- (Can't change the host's address, but as a sanity check.)
+ipv4 :: String -> Property
+ipv4 addr = pureAttrProperty ("ipv4 " ++ addr)
+	(addDNS $ Address $ IPv4 addr)
 
-cnameFor :: IsProp p => Domain -> (Domain -> p) -> AttrProperty
-cnameFor domain mkp =
-	let p = mkp domain
-	in AttrProperty p (addCName domain)
+-- | Indidate that a host has an AAAA record in the DNS.
+ipv6 :: String -> Property
+ipv6 addr = pureAttrProperty ("ipv6 " ++ addr)
+	(addDNS $ Address $ IPv6 addr)
 
-addCName :: HostName -> Attr -> Attr
-addCName domain d = d { _cnames = S.insert domain (_cnames d) }
+-- | Indicates another name for the host in the DNS.
+alias :: Domain -> Property
+alias domain = pureAttrProperty ("aka " ++ domain)
+	(addDNS $ CNAME $ AbsDomain domain)
 
-sshPubKey :: String -> AttrProperty
+addDNS :: Record -> SetAttr
+addDNS record d = d { _dns = S.insert record (_dns d) }
+
+-- | Adds a DNS NamedConf stanza.
+--
+-- Note that adding a Master stanza for a domain always overrides an
+-- existing Secondary stanza, while a Secondary stanza is only added
+-- when there is no existing Master stanza.
+addNamedConf :: NamedConf -> SetAttr
+addNamedConf conf d = d { _namedconf = new }
+  where
+	m = _namedconf d
+	domain = confDomain conf
+	new = case (confType conf, confType <$> M.lookup domain m) of
+		(Secondary, Just Master) -> m
+		_  -> M.insert domain conf m
+
+getNamedConf :: Propellor (M.Map Domain NamedConf)
+getNamedConf = asks _namedconf
+
+sshPubKey :: String -> Property
 sshPubKey k = pureAttrProperty ("ssh pubkey known") $
 	\d -> d { _sshPubKey = Just k }
 
@@ -58,8 +85,21 @@
 hostMap :: [Host] -> M.Map HostName Host
 hostMap l = M.fromList $ zip (map (_hostname . hostAttr) l) l 
 
+hostAttrMap :: [Host] -> M.Map HostName Attr
+hostAttrMap l = M.fromList $ zip (map _hostname attrs) attrs
+  where
+	attrs = map hostAttr l
+
 findHost :: [Host] -> HostName -> Maybe Host
 findHost l hn = M.lookup hn (hostMap l)
+
+getAddresses :: Attr -> [IPAddr]
+getAddresses = mapMaybe getIPAddr . S.toList . _dns
+
+hostAddresses :: HostName -> [Host] -> [IPAddr]
+hostAddresses hn hosts = case hostAttr <$> findHost hosts hn of
+	Nothing -> []
+	Just attr -> mapMaybe getIPAddr $ S.toList $ _dns attr
 
 -- | Lifts an action into a different host.
 --
diff --git a/Propellor/Engine.hs b/Propellor/Engine.hs
--- a/Propellor/Engine.hs
+++ b/Propellor/Engine.hs
@@ -18,7 +18,7 @@
 mainProperties :: Attr -> [Property] -> IO ()
 mainProperties attr ps = do
 	r <- runPropellor attr $
-		ensureProperties [Property "overall" $ ensureProperties ps]
+		ensureProperties [Property "overall" (ensureProperties ps) id]
 	setTitle "propellor: done"
 	hFlush stdout
 	case r of
diff --git a/Propellor/Property.hs b/Propellor/Property.hs
--- a/Propellor/Property.hs
+++ b/Propellor/Property.hs
@@ -5,6 +5,7 @@
 import System.Directory
 import Control.Monad
 import Data.Monoid
+import Data.List
 import Control.Monad.IfElse
 import "mtl" Control.Monad.Reader
 
@@ -15,23 +16,21 @@
 import Utility.Monad
 import System.FilePath
 
-makeChange :: IO () -> Propellor Result
-makeChange a = liftIO a >> return MadeChange
-
-noChange :: Propellor Result
-noChange = return NoChange
+-- Constructs a Property.
+property :: Desc -> Propellor Result -> Property
+property d s = Property d s id
 
 -- | Combines a list of properties, resulting in a single property
 -- that when run will run each property in the list in turn,
 -- and print out the description of each as it's run. Does not stop
 -- on failure; does propigate overall success/failure.
 propertyList :: Desc -> [Property] -> Property
-propertyList desc ps = Property desc $ ensureProperties ps
+propertyList desc ps = Property desc (ensureProperties ps) (combineSetAttrs ps)
 
 -- | Combines a list of properties, resulting in one property that
 -- ensures each in turn, stopping on failure.
 combineProperties :: Desc -> [Property] -> Property
-combineProperties desc ps = Property desc $ go ps NoChange
+combineProperties desc ps = Property desc (go ps NoChange) (combineSetAttrs ps)
   where
   	go [] rs = return rs
 	go (l:ls) rs = do
@@ -44,26 +43,23 @@
 -- that ensures the first, and if the first succeeds, ensures the second.
 -- The property uses the description of the first property.
 before :: Property -> Property -> Property
-p1 `before` p2 = Property (propertyDesc p1) $ do
-	r <- ensureProperty p1
-	case r of
-		FailedChange -> return FailedChange
-		_ -> ensureProperty p2
+p1 `before` p2 = p2 `requires` p1
+	`describe` (propertyDesc p1)
 
 -- | Makes a perhaps non-idempotent Property be idempotent by using a flag
 -- file to indicate whether it has run before.
 -- Use with caution.
 flagFile :: Property -> FilePath -> Property
-flagFile property = flagFile' property . return
+flagFile p = flagFile' p . return
 
 flagFile' :: Property -> IO FilePath -> Property
-flagFile' property getflagfile = Property (propertyDesc property) $ do
+flagFile' p getflagfile = adjustProperty p $ \satisfy -> do
 	flagfile <- liftIO getflagfile
-	go flagfile =<< liftIO (doesFileExist flagfile)
+	go satisfy flagfile =<< liftIO (doesFileExist flagfile)
   where
-	go _ True = return NoChange
-	go flagfile False = do
-		r <- ensureProperty property
+	go _ _ True = return NoChange
+	go satisfy flagfile False = do
+		r <- satisfy
 		when (r == MadeChange) $ liftIO $ 
 			unlessM (doesFileExist flagfile) $ do
 				createDirectoryIfMissing True (takeDirectory flagfile)
@@ -73,22 +69,24 @@
 --- | Whenever a change has to be made for a Property, causes a hook
 -- Property to also be run, but not otherwise.
 onChange :: Property -> Property -> Property
-property `onChange` hook = Property (propertyDesc property) $ do
-	r <- ensureProperty property
-	case r of
-		MadeChange -> do
-			r' <- ensureProperty hook
-			return $ r <> r'
-		_ -> return r
+p `onChange` hook = Property (propertyDesc p) satisfy (combineSetAttr p hook)
+  where
+	satisfy = do
+		r <- ensureProperty p
+		case r of
+			MadeChange -> do
+				r' <- ensureProperty hook
+				return $ r <> r'
+			_ -> return r
 
 (==>) :: Desc -> Property -> Property
 (==>) = flip describe
 infixl 1 ==>
 
--- | Makes a Property only be performed when a test succeeds.
+-- | Makes a Property only need to do anything when a test succeeds.
 check :: IO Bool -> Property -> Property
-check c property = Property (propertyDesc property) $ ifM (liftIO c)
-	( ensureProperty property
+check c p = adjustProperty p $ \satisfy -> ifM (liftIO c)
+	( satisfy
 	, return NoChange
 	)
 
@@ -99,8 +97,8 @@
 -- to be made as it is to just idempotently assure the property is
 -- satisfied. For example, chmodding a file.
 trivial :: Property -> Property
-trivial p = Property (propertyDesc p) $ do
-	r <- ensureProperty p
+trivial p = adjustProperty p $ \satisfy -> do
+	r <- satisfy
 	if r == MadeChange
 		then return NoChange
 		else return r
@@ -110,10 +108,10 @@
 --
 -- Note that the operating system may not be declared for some hosts.
 withOS :: Desc -> (Maybe System -> Propellor Result) -> Property
-withOS desc a = Property desc $ a =<< getOS
+withOS desc a = property desc $ a =<< getOS
 
 boolProperty :: Desc -> IO Bool -> Property
-boolProperty desc a = Property desc $ ifM (liftIO a)
+boolProperty desc a = property desc $ ifM (liftIO a)
 	( return MadeChange
 	, return FailedChange
 	)
@@ -133,16 +131,33 @@
 
 -- | Adds a property to a Host
 --
--- Can add Properties, RevertableProperties, and AttrProperties
+-- Can add Properties and RevertableProperties
 (&) :: IsProp p => Host -> p -> Host
-(Host ps as) & p = Host (ps ++ [toProp p]) (getAttr p . as)
+(Host ps as) & p = Host (ps ++ [toProp p]) (setAttr p . as)
 
 infixl 1 &
 
 -- | Adds a property to the Host in reverted form.
 (!) :: Host -> RevertableProperty -> Host
-(Host ps as) ! p = Host (ps ++ [toProp q]) (getAttr q . as)
+(Host ps as) ! p = Host (ps ++ [toProp q]) (setAttr q . as)
   where
 	q = revert p
 
 infixl 1 !
+
+-- 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) }
+
+-- Combines the Attr settings of two properties.
+combineSetAttr :: (IsProp p, IsProp q) => p -> q -> SetAttr
+combineSetAttr p q = setAttr p . setAttr q
+
+combineSetAttrs :: IsProp p => [p] -> SetAttr
+combineSetAttrs = foldl' (.) id . map setAttr
+
+makeChange :: IO () -> Propellor Result
+makeChange a = liftIO a >> return MadeChange
+
+noChange :: Propellor Result
+noChange = return NoChange
diff --git a/Propellor/Property/Apt.hs b/Propellor/Property/Apt.hs
--- a/Propellor/Property/Apt.hs
+++ b/Propellor/Property/Apt.hs
@@ -17,6 +17,8 @@
 type Url = String
 type Section = String
 
+type SourcesGenerator = DebianSuite -> [Line]
+
 showSuite :: DebianSuite -> String
 showSuite Stable = "stable"
 showSuite Testing = "testing"
@@ -39,7 +41,7 @@
 stdSections :: [Section]
 stdSections = ["main", "contrib", "non-free"]
 
-binandsrc :: String -> DebianSuite -> [Line]
+binandsrc :: String -> SourcesGenerator
 binandsrc url suite
 	| isStable suite = [l, srcLine l, bl, srcLine bl]
 	| otherwise = [l, srcLine l]
@@ -47,14 +49,14 @@
 	l = debLine (showSuite suite) url stdSections
 	bl = debLine backportSuite url stdSections
 
-debCdn :: DebianSuite -> [Line]
+debCdn :: SourcesGenerator
 debCdn = binandsrc "http://cdn.debian.net/debian"
 
-kernelOrg :: DebianSuite -> [Line]
+kernelOrg :: SourcesGenerator
 kernelOrg = binandsrc "http://mirrors.kernel.org/debian"
 
 -- | Only available for Stable and Testing
-securityUpdates :: DebianSuite -> [Line]
+securityUpdates :: SourcesGenerator
 securityUpdates suite
 	| isStable suite || suite == Testing =
 		let l = "deb http://security.debian.org/ " ++ showSuite suite ++ "/updates " ++ unwords stdSections
@@ -67,13 +69,27 @@
 -- Since the CDN is sometimes unreliable, also adds backup lines using
 -- kernel.org.
 stdSourcesList :: DebianSuite -> Property
-stdSourcesList suite = setSourcesList
-	(concatMap (\gen -> gen suite) [debCdn, kernelOrg, securityUpdates])
+stdSourcesList suite = stdSourcesList' suite []
+
+-- | Adds additional sources.list generators.
+--
+-- Note that if a Property needs to enable an apt source, it's better
+-- to do so via a separate file in /etc/apt/sources.list.d/
+stdSourcesList' :: DebianSuite -> [SourcesGenerator] -> Property
+stdSourcesList' suite more = setSourcesList
+	(concatMap (\gen -> gen suite) generators)
 	`describe` ("standard sources.list for " ++ show suite)
+  where
+	generators = [debCdn, kernelOrg, securityUpdates] ++ more
 
 setSourcesList :: [Line] -> Property
 setSourcesList ls = sourcesList `File.hasContent` ls `onChange` update
 
+setSourcesListD :: [Line] -> FilePath -> Property
+setSourcesListD ls basename = f `File.hasContent` ls `onChange` update
+  where
+	f = "/etc/apt/sources.list.d/" ++ basename ++ ".list"
+
 runApt :: [String] -> Property
 runApt ps = cmdProperty' "apt-get" ps noninteractiveEnv
 
@@ -141,8 +157,8 @@
 -- | Package installation may fail becuse the archive has changed.
 -- Run an update in that case and retry.
 robustly :: Property -> Property
-robustly p = Property (propertyDesc p) $ do
-	r <- ensureProperty p
+robustly p = adjustProperty p $ \satisfy -> do
+	r <- satisfy
 	if r == FailedChange
 		then ensureProperty $ p `requires` update
 		else return r
@@ -194,7 +210,7 @@
 reConfigure package vals = reconfigure `requires` setselections
 	`describe` ("reconfigure " ++ package)
   where
-	setselections = Property "preseed" $ makeChange $
+	setselections = property "preseed" $ makeChange $
 		withHandle StdinHandle createProcessSuccess
 			(proc "debconf-set-selections" []) $ \h -> do
 				forM_ vals $ \(tmpl, tmpltype, value) ->
@@ -208,3 +224,21 @@
 -- package names.
 serviceInstalledRunning :: Package -> Property
 serviceInstalledRunning svc = Service.running svc `requires` installed [svc]
+
+data AptKey = AptKey
+	{ keyname :: String
+	, pubkey :: String
+	}
+
+trustsKey :: AptKey -> RevertableProperty
+trustsKey k = RevertableProperty trust untrust
+  where
+	desc = "apt trusts key " ++ keyname k
+	f = "/etc/apt/trusted.gpg.d" </> keyname k ++ ".gpg"
+	untrust = File.notPresent f
+	trust = check (not <$> doesFileExist f) $ property desc $ makeChange $ do
+		withHandle StdinHandle createProcessSuccess
+			(proc "gpg" ["--no-default-keyring", "--keyring", f, "--import", "-"]) $ \h -> do
+				hPutStr h (pubkey k)
+				hClose h
+		nukeFile $ f ++ "~" -- gpg dropping
diff --git a/Propellor/Property/Cmd.hs b/Propellor/Property/Cmd.hs
--- a/Propellor/Property/Cmd.hs
+++ b/Propellor/Property/Cmd.hs
@@ -12,6 +12,7 @@
 import "mtl" Control.Monad.Reader
 
 import Propellor.Types
+import Propellor.Property
 import Utility.Monad
 import Utility.SafeCommand
 import Utility.Env
@@ -25,7 +26,7 @@
 -- | A property that can be satisfied by running a command,
 -- with added environment.
 cmdProperty' :: String -> [String] -> [(String, String)] -> Property
-cmdProperty' cmd params env = Property desc $ liftIO $ do
+cmdProperty' cmd params env = property desc $ liftIO $ do
 	env' <- addEntries env <$> getEnvironment
 	ifM (boolSystemEnv cmd (map Param params) (Just env'))
 		( return MadeChange
diff --git a/Propellor/Property/Cron.hs b/Propellor/Property/Cron.hs
--- a/Propellor/Property/Cron.hs
+++ b/Propellor/Property/Cron.hs
@@ -16,6 +16,8 @@
 -- Only one instance of the cron job is allowed to run at a time, no matter
 -- how long it runs. This is accomplished using flock locking of the cron
 -- job file.
+--
+-- The cron job's output will only be emailed if it exits nonzero.
 job :: Desc -> CronTimes -> UserName -> FilePath -> String -> Property
 job desc times user cddir command = cronjobfile `File.hasContent`
 	[ "# Generated by propellor"
@@ -24,13 +26,14 @@
 	, "PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin"
 	, ""
 	, times ++ "\t" ++ user ++ "\t"
-		++ "flock -n " ++ shellEscape cronjobfile
+		++ "chronic flock -n " ++ shellEscape cronjobfile
 		++ " sh -c " ++ shellEscape cmdline
 	]
 	`requires` Apt.serviceInstalledRunning "cron"
+	`requires` Apt.installed ["util-linux", "moreutils"]
 	`describe` ("cronned " ++ desc)
   where
-	cmdline = "cd " ++ cddir ++ " && " ++ command
+	cmdline = "cd " ++ cddir ++ " && ( " ++ command ++ " )"
 	cronjobfile = "/etc/cron.d/" ++ map sanitize desc
 	sanitize c
 		| isAlphaNum c = c
@@ -40,8 +43,7 @@
 niceJob :: Desc -> CronTimes -> UserName -> FilePath -> String -> Property
 niceJob desc times user cddir command = job desc times user cddir
 	("nice ionice -c 3 " ++ command)
-	`requires` Apt.installed ["util-linux", "moreutils"]
 
 -- | Installs a cron job to run propellor.
 runPropellor :: CronTimes -> Property
-runPropellor times = niceJob "propellor" times "root" localdir "chronic make"
+runPropellor times = niceJob "propellor" times "root" localdir "make"
diff --git a/Propellor/Property/Dns.hs b/Propellor/Property/Dns.hs
--- a/Propellor/Property/Dns.hs
+++ b/Propellor/Property/Dns.hs
@@ -1,49 +1,128 @@
-module Propellor.Property.Dns where
+module Propellor.Property.Dns (
+	module Propellor.Types.Dns,
+	primary,
+	secondary,
+	secondaryFor,
+	mkSOA,
+	rootAddressesFrom,
+	writeZoneFile,
+	nextSerialNumber,
+	adjustSerialNumber,
+	serialNumberOffset,
+	genZone,
+) where
 
 import Propellor
+import Propellor.Types.Dns
 import Propellor.Property.File
+import Propellor.Types.Attr
 import qualified Propellor.Property.Apt as Apt
 import qualified Propellor.Property.Service as Service
-
-namedconf :: FilePath
-namedconf = "/etc/bind/named.conf.local"
-
-data Zone = Zone
-	{ zdomain :: Domain
-	, ztype :: Type
-	, zfile :: FilePath
-	, zmasters :: [IPAddr]
-	, zconfiglines :: [String]
-	}
+import Utility.Applicative
 
-zoneDesc :: Zone -> String
-zoneDesc z = zdomain z ++ " (" ++ show (ztype z) ++ ")"
+import qualified Data.Map as M
+import qualified Data.Set as S
+import Data.List
 
-type IPAddr = String
+-- | Primary dns server for a domain.
+--
+-- Most of the content of the zone file is configured by setting properties
+-- of hosts. For example,
+--
+-- > host "foo.example.com"
+-- >   & ipv4 "192.168.1.1"
+-- >   & alias "mail.exmaple.com"
+--
+-- Will cause that hostmame and its alias to appear in the zone file,
+-- with the configured IP address.
+--
+-- The [(Domain, Record)] list can be used for additional records
+-- that cannot be configured elsewhere. For example, it might contain
+-- CNAMEs pointing at hosts that propellor does not control.
+primary :: [Host] -> Domain -> SOA -> [(BindDomain, Record)] -> Property
+primary hosts domain soa rs = withwarnings (check needupdate baseprop)
+	`requires` servingZones
+	`onChange` Service.reloaded "bind9"
+  where
+	(partialzone, warnings) = genZone hosts domain soa
+	zone = partialzone { zHosts = zHosts partialzone ++ rs }
+	zonefile = "/etc/bind/propellor/db." ++ domain
+	baseprop = Property ("dns primary for " ++ domain)
+		(makeChange $ writeZoneFile zone zonefile)
+		(addNamedConf conf)
+	withwarnings p = adjustProperty p $ \satisfy -> do
+		mapM_ warningMessage warnings
+		satisfy
+	conf = NamedConf
+		{ confDomain = domain
+		, confType = Master
+		, confFile = zonefile
+		, confMasters = []
+		, confLines = []
+		}
+	needupdate = do
+		v <- readZonePropellorFile zonefile
+		return $ case v of
+			Nothing -> True
+			Just oldzone ->
+				-- compare everything except serial
+				let oldserial = sSerial (zSOA oldzone)
+				    z = zone { zSOA = (zSOA zone) { sSerial = oldserial } }
+				in z /= oldzone || oldserial < sSerial (zSOA zone)
 
-type Domain = String
+-- | Secondary dns server for a domain.
+--
+-- The primary server is determined by looking at the properties of other
+-- hosts to find which one is configured as the primary.
+--
+-- Note that if a host is declared to be a primary and a secondary dns
+-- server for the same domain, the primary server config always wins.
+secondary :: [Host] -> Domain -> Property
+secondary hosts domain = secondaryFor masters hosts domain
+  where
+	masters = M.keys $ M.filter ismaster $ hostAttrMap hosts
+	ismaster attr = case M.lookup domain (_namedconf attr) of
+		Nothing -> False
+		Just conf -> confType conf == Master && confDomain conf == domain
 
-data Type = Master | Secondary
-	deriving (Show, Eq)
+-- | This variant is useful if the primary server does not have its DNS
+-- configured via propellor.
+secondaryFor :: [HostName] -> [Host] -> Domain -> Property
+secondaryFor masters hosts domain = pureAttrProperty desc (addNamedConf conf)
+	`requires` servingZones
+  where
+ 	desc = "dns secondary for " ++ domain
+	conf = NamedConf
+		{ confDomain = domain
+		, confType = Secondary
+		, confFile = "db." ++ domain
+		, confMasters = concatMap (\m -> hostAddresses m hosts) masters
+		, confLines = ["allow-transfer { }"]
+		}
 
-secondary :: Domain -> [IPAddr] -> Zone
-secondary domain masters = Zone
-	{ zdomain = domain
-	, ztype = Secondary
-	, zfile = "db." ++ domain
-	, zmasters = masters
-	, zconfiglines = ["allow-transfer { }"]
-	}
+-- | Rewrites the whole named.conf.local file to serve the zones
+-- configured by `primary` and `secondary`, and ensures that bind9 is
+-- running.
+servingZones :: Property
+servingZones = property "serving configured dns zones" go
+	`requires` Apt.serviceInstalledRunning "bind9"
+	`onChange` Service.reloaded "bind9"
+  where
+	go = do
+		zs <- getNamedConf
+		ensureProperty $
+			hasContent namedConfFile $
+				concatMap confStanza $ M.elems zs
 
-zoneStanza :: Zone -> [Line]
-zoneStanza z =
+confStanza :: NamedConf -> [Line]
+confStanza c =
 	[ "// automatically generated by propellor"
-	, "zone \"" ++ zdomain z ++ "\" {"
-	, cfgline "type" (if ztype z == Master then "master" else "slave")
-	, cfgline "file" ("\"" ++ zfile z ++ "\"")
+	, "zone \"" ++ confDomain c ++ "\" {"
+	, cfgline "type" (if confType c == Master then "master" else "slave")
+	, cfgline "file" ("\"" ++ confFile c ++ "\"")
 	] ++
-	(if null (zmasters z) then [] else mastersblock) ++
-	(map (\l -> "\t" ++ l ++ ";") (zconfiglines z)) ++
+	(if null (confMasters c) then [] else mastersblock) ++
+	(map (\l -> "\t" ++ l ++ ";") (confLines c)) ++
 	[ "};"
 	, ""
 	]
@@ -51,13 +130,242 @@
 	cfgline f v = "\t" ++ f ++ " " ++ v ++ ";"
 	mastersblock =
 		[ "\tmasters {" ] ++
-		(map (\ip -> "\t\t" ++ ip ++ ";") (zmasters z)) ++
+		(map (\ip -> "\t\t" ++ fromIPAddr ip ++ ";") (confMasters c)) ++
 		[ "\t};" ]
 
--- | Rewrites the whole named.conf.local file to serve the specificed
--- zones.
-zones :: [Zone] -> Property
-zones zs = hasContent namedconf (concatMap zoneStanza zs)
-	`describe` ("dns server for zones: " ++ unwords (map zoneDesc zs))
-	`requires` Apt.serviceInstalledRunning "bind9"
-	`onChange` Service.reloaded "bind9"
+namedConfFile :: FilePath
+namedConfFile = "/etc/bind/named.conf.local"
+
+-- | Generates a SOA with some fairly sane numbers in it.
+--
+-- The Domain is the domain to use in the SOA record. Typically
+-- something like ns1.example.com. So, not the domain that this is the SOA
+-- record for.
+--
+-- The SerialNumber can be whatever serial number was used by the domain
+-- before propellor started managing it. Or 0 if the domain has only ever
+-- been managed by propellor.
+--
+-- You do not need to increment the SerialNumber when making changes!
+-- Propellor will automatically add the number of commits in the git
+-- repository to the SerialNumber.
+--
+-- Handy trick: You don't need to list IPAddrs in the [Record],
+-- just make some Host sets its `alias` to the root of domain.
+mkSOA :: Domain -> SerialNumber -> [Record] -> SOA
+mkSOA d sn rs = SOA
+	{ sDomain = AbsDomain d
+	, sSerial = sn
+	, sRefresh = hours 4
+	, sRetry = hours 1
+	, sExpire = 2419200 -- 4 weeks
+	, sNegativeCacheTTL = hours 8
+	, sRecord = rs
+	}
+  where
+	hours n = n * 60 * 60
+
+rootAddressesFrom :: [Host] -> HostName -> [Record]
+rootAddressesFrom hosts hn = map Address (hostAddresses hn hosts)
+
+dValue :: BindDomain -> String
+dValue (RelDomain d) = d
+dValue (AbsDomain d) = d ++ "."
+dValue (SOADomain) = "@"
+
+rField :: Record -> String
+rField (Address (IPv4 _)) = "A"
+rField (Address (IPv6 _)) = "AAAA"
+rField (CNAME _) = "CNAME"
+rField (MX _ _) = "MX"
+rField (NS _) = "NS"
+rField (TXT _) = "TXT"
+rField (SRV _ _ _ _) = "SRV"
+
+rValue :: Record -> String
+rValue (Address (IPv4 addr)) = addr
+rValue (Address (IPv6 addr)) = addr
+rValue (CNAME d) = dValue d
+rValue (MX pri d) = show pri ++ " " ++ dValue d
+rValue (NS d) = dValue d
+rValue (SRV priority weight port target) = unwords
+	[ show priority
+	, show weight
+	, show port
+	, dValue target
+	]
+rValue (TXT s) = [q] ++ filter (/= q) s ++ [q]
+  where
+	q = '"'
+
+-- | Adjusts the serial number of the zone to 
+--
+-- * Always be larger than the serial number in the Zone record.
+-- * Always be larger than the passed SerialNumber
+nextSerialNumber :: Zone -> SerialNumber -> Zone
+nextSerialNumber z serial = adjustSerialNumber z $ \sn -> succ $ max sn serial
+
+adjustSerialNumber :: Zone -> (SerialNumber -> SerialNumber) -> Zone
+adjustSerialNumber (Zone d soa l) f = Zone d soa' l
+  where
+	soa' = soa { sSerial = f (sSerial soa) }
+
+-- | Count the number of git commits made to the current branch.
+serialNumberOffset :: IO SerialNumber
+serialNumberOffset = fromIntegral . length . lines
+	<$> readProcess "git" ["log", "--pretty=%H"]
+
+-- | Write a Zone out to a to a file.
+--
+-- The serial number in the Zone automatically has the serialNumberOffset
+-- added to it. Also, just in case, the old serial number used in the zone
+-- file is checked, and if it is somehow larger, its succ is used.
+writeZoneFile :: Zone -> FilePath -> IO ()
+writeZoneFile z f = do
+	oldserial <- oldZoneFileSerialNumber f
+	offset <- serialNumberOffset
+	let z' = nextSerialNumber
+		(adjustSerialNumber z (+ offset))
+		oldserial
+	createDirectoryIfMissing True (takeDirectory f)
+	writeFile f (genZoneFile z')
+	writeZonePropellorFile f z'
+
+-- | Next to the zone file, is a ".propellor" file, which contains
+-- the serialized Zone. This saves the bother of parsing
+-- the horrible bind zone file format.
+zonePropellorFile :: FilePath -> FilePath
+zonePropellorFile f = f ++ ".propellor"
+
+oldZoneFileSerialNumber :: FilePath -> IO SerialNumber
+oldZoneFileSerialNumber = maybe 0 (sSerial . zSOA) <$$> readZonePropellorFile
+
+writeZonePropellorFile :: FilePath -> Zone -> IO ()
+writeZonePropellorFile f z = writeFile (zonePropellorFile f) (show z)
+
+readZonePropellorFile :: FilePath -> IO (Maybe Zone)
+readZonePropellorFile f = catchDefaultIO Nothing $
+	readish <$> readFileStrict (zonePropellorFile f)
+
+-- | Generating a zone file.
+genZoneFile :: Zone -> String
+genZoneFile (Zone zdomain soa rs) = unlines $
+	header : genSOA zdomain soa ++ map genr rs
+  where
+	header = com $ "BIND zone file for " ++ zdomain ++ ". Generated by propellor, do not edit."
+
+	genr (d, r) = genRecord zdomain (Just d, r)
+
+genRecord :: Domain -> (Maybe BindDomain, Record) -> String
+genRecord zdomain (mdomain, record) = intercalate "\t"
+	[ hn
+	, "IN"
+	, rField record
+	, rValue record
+	]
+  where
+	hn = maybe "" (domainHost zdomain) mdomain
+
+genSOA :: Domain -> SOA -> [String]
+genSOA zdomain soa =
+	header ++ map (genRecord zdomain) (zip (repeat Nothing) (sRecord soa))
+  where
+	header =
+		-- "@ IN SOA ns1.example.com. root ("
+		[ intercalate "\t"
+			[ dValue SOADomain 
+			, "IN"
+			, "SOA"
+			, dValue (sDomain soa)
+			, "root"
+			, "("
+			]
+		, headerline sSerial "Serial"
+		, headerline sRefresh "Refresh"
+		, headerline sRetry "Retry"
+		, headerline sExpire "Expire"
+		, headerline sNegativeCacheTTL "Negative Cache TTL"
+		, inheader ")"
+		]
+	headerline r comment = inheader $ show (r soa) ++ "\t\t" ++ com comment
+	inheader l = "\t\t\t" ++ l
+
+-- | Comment line in a zone file.
+com :: String -> String
+com s = "; " ++ s
+
+type WarningMessage = String
+
+-- | Generates a Zone for a particular Domain from the DNS properies of all
+-- hosts that propellor knows about that are in that Domain.
+genZone :: [Host] -> Domain -> SOA -> (Zone, [WarningMessage])
+genZone hosts zdomain soa =
+	let (warnings, zhosts) = partitionEithers $ concat $ map concat
+		[ map hostips inzdomain
+		, map hostrecords inzdomain
+		, map addcnames (M.elems m)
+		]
+	in (Zone zdomain soa (nub zhosts), warnings)
+  where
+	m = hostAttrMap hosts
+	-- Known hosts with hostname located in the zone's domain.
+	inzdomain = M.elems $ M.filterWithKey (\hn _ -> inDomain zdomain $ AbsDomain $ hn) m
+	
+	-- Each host with a hostname located in the zdomain
+	-- should have 1 or more IPAddrs in its Attr.
+	--
+	-- If a host lacks any IPAddr, it's probably a misconfiguration,
+	-- so warn.
+	hostips :: Attr -> [Either WarningMessage (BindDomain, Record)]
+	hostips attr
+		| null l = [Left $ "no IP address defined for host " ++ _hostname attr]
+		| otherwise = map Right l
+	  where
+		l = zip (repeat $ AbsDomain $ _hostname attr)
+			(map Address $ getAddresses attr)
+
+	-- Any host, whether its hostname is in the zdomain or not,
+	-- may have cnames which are in the zdomain. The cname may even be
+	-- the same as the root of the zdomain, which is a nice way to
+	-- specify IP addresses for a SOA record.
+	--
+	-- Add Records for those.. But not actually, usually, cnames!
+	-- Why not? Well, using cnames doesn't allow doing some things,
+	-- including MX and round robin DNS, and certianly CNAMES
+	-- shouldn't be used in SOA records.
+	--
+	-- We typically know the host's IPAddrs anyway.
+	-- So we can just use the IPAddrs.
+	addcnames :: Attr -> [Either WarningMessage (BindDomain, Record)]
+	addcnames attr = concatMap gen $ filter (inDomain zdomain) $
+		mapMaybe getCNAME $ S.toList (_dns attr)
+	  where
+		gen c = case getAddresses attr of
+			[] -> [ret (CNAME c)]
+			l -> map (ret . Address) l
+		  where
+		  	ret record = Right (c, record)
+	
+	-- Adds any other DNS records for a host located in the zdomain.
+	hostrecords :: Attr -> [Either WarningMessage (BindDomain, Record)]
+	hostrecords attr = map Right l
+	  where
+		l = zip (repeat $ AbsDomain $ _hostname attr)
+			(S.toList $ S.filter (\r -> isNothing (getIPAddr r) && isNothing (getCNAME r)) (_dns attr))
+
+inDomain :: Domain -> BindDomain -> Bool
+inDomain domain (AbsDomain d) = domain == d || ('.':domain) `isSuffixOf` d
+inDomain _ _ = False -- can't tell, so assume not
+
+-- | Gets the hostname of the second domain, relative to the first domain,
+-- suitable for using in a zone file.
+domainHost :: Domain -> BindDomain -> String
+domainHost _ (RelDomain d) = d
+domainHost _ SOADomain = "@"
+domainHost base (AbsDomain d)
+	| dotbase `isSuffixOf` d = take (length d - length dotbase) d
+	| base == d = "@"
+	| otherwise = d
+  where
+	dotbase = '.':base
+
diff --git a/Propellor/Property/Docker.hs b/Propellor/Property/Docker.hs
--- a/Propellor/Property/Docker.hs
+++ b/Propellor/Property/Docker.hs
@@ -25,7 +25,7 @@
 -- | Configures docker with an authentication file, so that images can be
 -- pushed to index.docker.io.
 configured :: Property
-configured = Property "docker configured" go `requires` installed
+configured = property "docker configured" go `requires` installed
   where
 	go = withPrivData DockerAuthentication $ \cfg -> ensureProperty $ 
 		"/root/.dockercfg" `File.hasContent` (lines cfg)
@@ -64,7 +64,7 @@
 	-> RevertableProperty
 docked hosts cn = RevertableProperty (go "docked" setup) (go "undocked" teardown)
   where
-	go desc a = Property (desc ++ " " ++ cn) $ do
+	go desc a = property (desc ++ " " ++ cn) $ do
 		hn <- getHostName
   		let cid = ContainerId hn cn
 		ensureProperties [findContainer hosts cid cn $ a cid]
@@ -79,7 +79,7 @@
 	teardown cid (Container image _runparams) =
 		combineProperties ("undocked " ++ fromContainerId cid)
 			[ stoppedContainer cid
-			, Property ("cleaned up " ++ fromContainerId cid) $
+			, property ("cleaned up " ++ fromContainerId cid) $
 				liftIO $ report <$> mapM id
 					[ removeContainer cid
 					, removeImage image
@@ -96,7 +96,7 @@
 	Nothing -> cantfind
 	Just h -> maybe cantfind mk (mkContainer cid h)
   where
-	cantfind = containerDesc cid $ Property "" $ do
+	cantfind = containerDesc cid $ property "" $ do
 		liftIO $ warningMessage $
 			"missing definition for docker container \"" ++ cn2hn cn
 		return FailedChange
@@ -126,9 +126,9 @@
 	, gcimages
 	]
   where
-	gccontainers = Property "docker containers garbage collected" $
+	gccontainers = property "docker containers garbage collected" $
 		liftIO $ report <$> (mapM removeContainer =<< listContainers AllContainers)
-	gcimages = Property "docker images garbage collected" $ do
+	gcimages = property "docker images garbage collected" $ do
 		liftIO $ report <$> (mapM removeImage =<< listImages)
 
 data Container = Container Image [RunParam]
@@ -140,51 +140,51 @@
 type Image = String
 
 -- | Set custom dns server for container.
-dns :: String -> AttrProperty
+dns :: String -> Property
 dns = runProp "dns"
 
 -- | Set container host name.
-hostname :: String -> AttrProperty
+hostname :: String -> Property
 hostname = runProp "hostname"
 
 -- | Set name for container. (Normally done automatically.)
-name :: String -> AttrProperty
+name :: String -> Property
 name = runProp "name"
 
 -- | Publish a container's port to the host
 -- (format: ip:hostPort:containerPort | ip::containerPort | hostPort:containerPort)
-publish :: String -> AttrProperty
+publish :: String -> Property
 publish = runProp "publish"
 
 -- | Username or UID for container.
-user :: String -> AttrProperty
+user :: String -> Property
 user = runProp "user"
 
 -- | Mount a volume
 -- Create a bind mount with: [host-dir]:[container-dir]:[rw|ro]
 -- With just a directory, creates a volume in the container.
-volume :: String -> AttrProperty
+volume :: String -> Property
 volume = runProp "volume"
 
 -- | Mount a volume from the specified container into the current
 -- container.
-volumes_from :: ContainerName -> AttrProperty
+volumes_from :: ContainerName -> Property
 volumes_from cn = genProp "volumes-from" $ \hn ->
 	fromContainerId (ContainerId hn cn)
 
 -- | Work dir inside the container. 
-workdir :: String -> AttrProperty
+workdir :: String -> Property
 workdir = runProp "workdir"
 
 -- | Memory limit for container.
 --Format: <number><optional unit>, where unit = b, k, m or g
-memory :: String -> AttrProperty
+memory :: String -> Property
 memory = runProp "memory"
 
 -- | Link with another container on the same host.
-link :: ContainerName -> ContainerAlias -> AttrProperty
-link linkwith alias = genProp "link" $ \hn ->
-	fromContainerId (ContainerId hn linkwith) ++ ":" ++ alias
+link :: ContainerName -> ContainerAlias -> Property
+link linkwith calias = genProp "link" $ \hn ->
+	fromContainerId (ContainerId hn linkwith) ++ ":" ++ calias
 
 -- | A short alias for a linked container.
 -- Each container has its own alias namespace.
@@ -230,7 +230,7 @@
 	desc = "[" ++ fromContainerId cid ++ "] " ++ propertyDesc p
 
 runningContainer :: ContainerId -> Image -> [RunParam] -> Property
-runningContainer cid@(ContainerId hn cn) image runps = containerDesc cid $ Property "running" $ do
+runningContainer cid@(ContainerId hn cn) image runps = containerDesc cid $ property "running" $ do
 	l <- liftIO $ listContainers RunningContainers
 	if cid `elem` l
 		then do
@@ -324,7 +324,7 @@
 -- being run. So, retry connections to the client for up to
 -- 1 minute.
 provisionContainer :: ContainerId -> Property
-provisionContainer cid = containerDesc cid $ Property "provision" $ liftIO $ do
+provisionContainer cid = containerDesc cid $ property "provision" $ liftIO $ do
 	let shim = Shim.file (localdir </> "propellor") (localdir </> shimdir cid)
 	r <- simpleShClientRetry 60 (namedPipe cid) shim params (go Nothing)
 	when (r /= FailedChange) $
@@ -356,7 +356,7 @@
 stopContainer cid = boolSystem dockercmd [Param "stop", Param $ fromContainerId cid ]
 
 stoppedContainer :: ContainerId -> Property
-stoppedContainer cid = containerDesc cid $ Property desc $ 
+stoppedContainer cid = containerDesc cid $ property desc $ 
 	ifM (liftIO $ elem cid <$> listContainers RunningContainers)
 		( liftIO cleanup `after` ensureProperty 
 			(boolProperty desc $ stopContainer cid)
@@ -405,18 +405,15 @@
 listImages :: IO [Image]
 listImages = lines <$> readProcess dockercmd ["images", "--all", "--quiet"]
 
-runProp :: String -> RunParam -> AttrProperty
-runProp field val = AttrProperty prop $ \attr ->
+runProp :: String -> RunParam -> Property
+runProp field val = pureAttrProperty (param) $ \attr ->
 	attr { _dockerRunParams = _dockerRunParams attr ++ [\_ -> "--"++param] }
   where
 	param = field++"="++val
-	prop = Property (param) (return NoChange)
 
-genProp :: String -> (HostName -> RunParam) -> AttrProperty
-genProp field mkval = AttrProperty prop $ \attr ->
+genProp :: String -> (HostName -> RunParam) -> Property
+genProp field mkval = pureAttrProperty field $ \attr ->
 	attr { _dockerRunParams = _dockerRunParams attr ++ [\hn -> "--"++field++"=" ++ mkval hn] }
-  where
-	prop = Property field (return NoChange)
 
 -- | The ContainerIdent of a container is written to
 -- /.propellor-ident inside it. This can be checked to see if
diff --git a/Propellor/Property/File.hs b/Propellor/Property/File.hs
--- a/Propellor/Property/File.hs
+++ b/Propellor/Property/File.hs
@@ -18,7 +18,7 @@
 -- The file's permissions are preserved if the file already existed.
 -- Otherwise, they're set to 600.
 hasPrivContent :: FilePath -> Property
-hasPrivContent f = Property desc $ withPrivData (PrivFile f) $ \privcontent -> 
+hasPrivContent f = property desc $ withPrivData (PrivFile f) $ \privcontent -> 
 	ensureProperty $ fileProperty' writeFileProtected desc
 		(\_oldcontent -> lines privcontent) f
   where
@@ -48,13 +48,13 @@
 
 -- | Removes a file. Does not remove symlinks or non-plain-files.
 notPresent :: FilePath -> Property
-notPresent f = check (doesFileExist f) $ Property (f ++ " not present") $ 
+notPresent f = check (doesFileExist f) $ property (f ++ " not present") $ 
 	makeChange $ nukeFile f
 
 fileProperty :: Desc -> ([Line] -> [Line]) -> FilePath -> Property
 fileProperty = fileProperty' writeFile
 fileProperty' :: (FilePath -> String -> IO ()) -> Desc -> ([Line] -> [Line]) -> FilePath -> Property
-fileProperty' writer desc a f = Property desc $ go =<< liftIO (doesFileExist f)
+fileProperty' writer desc a f = property desc $ go =<< liftIO (doesFileExist f)
   where
 	go True = do
 		ls <- liftIO $ lines <$> readFile f
@@ -74,12 +74,12 @@
 
 -- | Ensures a directory exists.
 dirExists :: FilePath -> Property
-dirExists d = check (not <$> doesDirectoryExist d) $ Property (d ++ " exists") $
+dirExists d = check (not <$> doesDirectoryExist d) $ property (d ++ " exists") $
 	makeChange $ createDirectoryIfMissing True d
 
 -- | Ensures that a file/dir has the specified owner and group.
 ownerGroup :: FilePath -> UserName -> GroupName -> Property
-ownerGroup f owner group = Property (f ++ " owner " ++ og) $ do
+ownerGroup f owner group = property (f ++ " owner " ++ og) $ do
 	r <- ensureProperty $ cmdProperty "chown" [og, f]
 	if r == FailedChange
 		then return r
@@ -89,6 +89,6 @@
 
 -- | Ensures that a file/dir has the specfied mode.
 mode :: FilePath -> FileMode -> Property
-mode f v = Property (f ++ " mode " ++ show v) $ do
+mode f v = property (f ++ " mode " ++ show v) $ do
 	liftIO $ modifyFileMode f (\_old -> v)
 	noChange
diff --git a/Propellor/Property/Git.hs b/Propellor/Property/Git.hs
--- a/Propellor/Property/Git.hs
+++ b/Propellor/Property/Git.hs
@@ -62,7 +62,7 @@
 --
 -- A branch can be specified, to check out.
 cloned :: UserName -> RepoUrl -> FilePath -> Maybe Branch -> Property
-cloned owner url dir mbranch = check originurl (Property desc checkout)
+cloned owner url dir mbranch = check originurl (property desc checkout)
 	`requires` installed
   where
 	desc = "git cloned " ++ url ++ " to " ++ dir
diff --git a/Propellor/Property/Gpg.hs b/Propellor/Property/Gpg.hs
--- a/Propellor/Property/Gpg.hs
+++ b/Propellor/Property/Gpg.hs
@@ -21,7 +21,7 @@
 -- The GpgKeyId does not have to be a numeric id; it can just as easily
 -- be a description of the key.
 keyImported :: GpgKeyId -> UserName -> Property
-keyImported keyid user = flagFile' (Property desc go) genflag
+keyImported keyid user = flagFile' (property desc go) genflag
 	`requires` installed
   where
 	desc = user ++ " has gpg key " ++ show keyid
diff --git a/Propellor/Property/Hostname.hs b/Propellor/Property/Hostname.hs
--- a/Propellor/Property/Hostname.hs
+++ b/Propellor/Property/Hostname.hs
@@ -9,7 +9,7 @@
 -- A FQDN also configures /etc/hosts, with an entry for 127.0.1.1, which is
 -- standard at least on Debian to set the FDQN (127.0.0.1 is localhost).
 sane :: Property
-sane = Property ("sane hostname") (ensureProperty . setTo =<< getHostName)
+sane = property ("sane hostname") (ensureProperty . setTo =<< getHostName)
 
 setTo :: HostName -> Property
 setTo hn = combineProperties desc go
diff --git a/Propellor/Property/Obnam.hs b/Propellor/Property/Obnam.hs
--- a/Propellor/Property/Obnam.hs
+++ b/Propellor/Property/Obnam.hs
@@ -7,9 +7,6 @@
 
 import Data.List
 
-installed :: Property
-installed = Apt.installed ["obnam"]
-
 type ObnamParam = String
 
 -- | An obnam repository can be used by multiple clients. Obnam uses
@@ -68,7 +65,7 @@
 -- The restore is performed atomically; restoring to a temp directory
 -- and then moving it to the directory.
 restored :: FilePath -> [ObnamParam] -> Property
-restored dir params = Property (dir ++ " restored by obnam") go
+restored dir params = property (dir ++ " restored by obnam") go
 	`requires` installed
   where
 	go = ifM (liftIO needsRestore)
@@ -94,3 +91,65 @@
 				return MadeChange
 			, return FailedChange
 			)
+
+installed :: Property
+installed = Apt.installed ["obnam"]
+
+-- | Ensures that a recent version of obnam gets installed.
+--
+-- Only does anything for Debian Stable.
+latestVersion :: Property
+latestVersion = withOS "obnam latest version" $ \o -> case o of
+	(Just (System (Debian suite) _)) | isStable suite -> ensureProperty $
+		Apt.setSourcesListD (sources suite) "obnam"
+			`requires` toProp (Apt.trustsKey key)
+	_ -> noChange
+  where
+	sources suite = 
+		[ "deb http://code.liw.fi/debian " ++ Apt.showSuite suite ++ " main"
+		]
+	-- gpg key used by the code.liw.fi repository.
+	key = Apt.AptKey "obnam" $ unlines
+		[ "-----BEGIN PGP PUBLIC KEY BLOCK-----"
+		, "Version: GnuPG v1.4.9 (GNU/Linux)"
+		, ""
+		, "mQGiBEfzuTgRBACcVNG/H6QJqLx5qiQs2zmPe6D6BWOWHfgNgG4IWzNstm21YDxb"
+		, "KqwFG0gxcnZJGHkXAhkSfqTokYd0lc5eBemcA1pkceNjzMEX8wwiZ810HzJD4eEH"
+		, "sjoWR8+qKrZeixzZqReAfqztcXoBGKQ0u1R1vpg1txUa75OM4BUqaUbsmwCgmS4x"
+		, "DjMxSaUSPuu6vQ7ZGZBXSP0D/RQw8DBHMfsv3DiaqFqk8tkuUkpMFPIekHidSHlO"
+		, "EACbncqbbyHksyCpFNVNcQIDHrOLjOZK9BAXkSd8I3ww7U+nLdDcCblrW8CZnJtm"
+		, "ZYrxfaXaHZ/It9/RCAsQ+c8xtmyUPjsf//4Vf8olxNQHzgBSe5/LJRi4Vd53he+K"
+		, "YP4LA/9IZbjvVmm8+8Y0pQrTHlI6nTImtzdBXHc4+T3lLBj9XODHLozC2kSBOQky"
+		, "q/EisTITHTXL8vYg4NsKm5RTbPAuBwdtxcny8CXfOqKtGOdrebmKotGllTozzdPv"
+		, "9p53cuce6oJ2oMUodc074JOGTWwDSgLiJX4nViGcU1wy/vtQnrQkY29kZS5saXcu"
+		, "ZmkgYXJjaGl2ZSBrZXkgPGxpd0BsaXcuZmk+iGAEExECACAFAkfzuTgCGwMGCwkI"
+		, "BwMCBBUCCAMEFgIDAQIeAQIXgAAKCRBG53tJR95LscKrAJ0ZtKqa2x6Kplwa2mzx"
+		, "ItImbIGMJACdETqofDYzUN91yLAFlOnxAyrE+UyIRgQQEQIABgUCSFd5GgAKCRAf"
+		, "u5W/LZrMjqr8AJ4xPVHpW8ZNlgMwDSVb075RnA2DiACgg2SR69jAHFQOWV6xfLRr"
+		, "vh0bLKGJAhwEEAEIAAYFAktEyIwACgkQ61zh116FEfm7Lg//Wiy3TjWAk8YHUddv"
+		, "zOioYzCxQ985GsVhJGAVPqSGOc9vfTWBJZ8J3l0NnYTRpEGucmbF9G+mAt9iGXu6"
+		, "7yZkxyFdvbo7EDsqMU1wLOM6PiU+Un63MKlbTNmFn7OKE8aXPRAFgcyUO/qjdqoD"
+		, "sa9FgU5Z0f60m9qah6BPXH6IzMLHYoiP7t8rCBIwLgyl3w2w+Fjt1DFpbW9Kb7jz"
+		, "i8jFvC8jPmxV8xh2OSgVZyNk4qg6hIV8GVQY7AJt8OurZSckgQd7ifHK9JTGohtF"
+		, "tXCiqeDEvnMF4A9HI/TcXJBzonZ8ds1JCq42nSSKmL+8TyjtUSD/xHygazuc0CK0"
+		, "hFnQWBub60IfyV6F0oTagJ8cmARv2sezHAeHDkzPHE8RdjgktazH1eJrA4LheEd6"
+		, "KeSnVtYWpw8dgMv5PleFyQiAj/t3C/N50fd15tUyfnH15G7nFjMQV2Yx35uwSxOj"
+		, "376OWnDN/YGTNk283XXULbyVJYR8Q2unso20XQ94yQ2A5EpHHPrHoLxrL/ydM08d"
+		, "nvKstLZIZtal1seiMkymtlSiGz25A5oqsclwS6VZCKdWA8HO/wlElOMcaHyl6Y1y"
+		, "gYP7y9O5yFYKFOrCH0nFjJbwmkRiBLsxuuWsYgJigVGq/atSrtawkHdshpCw0HCY"
+		, "N/RFcWkJ864BdsO0C0sDzueNkQO5Ag0ER/O5RBAIAJiwPH9tyJTgXcC2Y4XWboOq"
+		, "rx5CkOnr5b45oS9cK2eIJ8TKxE3XgKLxUr3mIH0QR2kZgDOwNl0WY+7/CXjn+Spn"
+		, "BokPg54rafEUePodGpGdUXdgrHhAMHYjh8fXFJ1SlQcg46/zc1wDI7jBCkGrK3V8"
+		, "5cXDqwTFTN5LcjoSRWeM4Voa6pEfDdL3rMlnOw9R9gDHRBBb6CDSjWXqM86pR889"
+		, "5QrR0SDwiJNrMoyxSjMXFKGBQAsYHJ82myZrlbuZbroZjVp5Uh7eB1ZiPljNVtcr"
+		, "sksACIWBCo1rvLzrPXsLYOeV3cDDtYAkSwGfuzC1Etbe+qgfIroFTOqdefMw4s8A"
+		, "AwUH/0KLXm4MS54QQspg3evu4Q4U/E8Hem5/FqB0GhBCitQ4rUsucKyY8/ItpUn5"
+		, "ismLE60bQqka+Mzd/Zw18TCTzImv0ozAaZ2sNtBado7f6jcC8EDfY5zzK1ukcsAr"
+		, "Qc5hdLHYuTQW5KpA6fKaW969OUzIwPbdVaCOLOBpxKC6N6iBspQYd6uiQtLw6EUO"
+		, "50oQqUiJABf0eOocvdw5e2KQQpuC3205+VMYtyl4w3pdJihK8NK0AikGXzDVsbQt"
+		, "l8kmB5ZrN4WIKhMke1FxbqQC5Q3XATvYRzpzzisZb/HYGNti8W6du5EUwJ0D2NRh"
+		, "cu+twocOzW0VKfmrDApfifJ9OsSISQQYEQIACQUCR/O5RAIbDAAKCRBG53tJR95L"
+		, "seQOAJ95KUyzjRjdYgZkDC69Mgu25L86UACdGduINUaRly43ag4kwUXxpqswBBM="
+		, "=i2c3"
+		, "-----END PGP PUBLIC KEY BLOCK-----"
+		]
diff --git a/Propellor/Property/Postfix.hs b/Propellor/Property/Postfix.hs
--- a/Propellor/Property/Postfix.hs
+++ b/Propellor/Property/Postfix.hs
@@ -15,7 +15,7 @@
 satellite :: Property
 satellite = setup `requires` installed
   where
-	setup = trivial $ Property "postfix satellite system" $ do
+	setup = trivial $ property "postfix satellite system" $ do
 		hn <- getHostName
 		ensureProperty $ Apt.reConfigure "postfix"
 			[ ("postfix/main_mailer_type", "select", "Satellite system")
diff --git a/Propellor/Property/Scheduled.hs b/Propellor/Property/Scheduled.hs
--- a/Propellor/Property/Scheduled.hs
+++ b/Propellor/Property/Scheduled.hs
@@ -19,13 +19,13 @@
 -- This uses the description of the Property to keep track of when it was
 -- last run.
 period :: Property -> Recurrance -> Property
-period prop recurrance = Property desc $ do
+period prop recurrance = flip describe desc $ adjustProperty prop $ \satisfy -> do
 	lasttime <- liftIO $ getLastChecked (propertyDesc prop)
 	nexttime <- liftIO $ fmap startTime <$> nextTime schedule lasttime
 	t <- liftIO localNow
 	if Just t >= nexttime
 		then do
-			r <- ensureProperty prop
+			r <- satisfy
 			liftIO $ setLastChecked t (propertyDesc prop)
 			return r
 		else noChange
@@ -37,7 +37,7 @@
 periodParse :: Property -> String -> Property
 periodParse prop s = case toRecurrance s of
 	Just recurrance -> period prop recurrance
-	Nothing -> Property "periodParse" $ do
+	Nothing -> property "periodParse" $ do
 		liftIO $ warningMessage $ "failed periodParse: " ++ s
 		noChange
 
diff --git a/Propellor/Property/Service.hs b/Propellor/Property/Service.hs
--- a/Propellor/Property/Service.hs
+++ b/Propellor/Property/Service.hs
@@ -13,19 +13,19 @@
 -- we can do is try to start the service, and if it fails, assume
 -- this means it's already running.
 running :: ServiceName -> Property
-running svc = Property ("running " ++ svc) $ do
+running svc = property ("running " ++ svc) $ do
 	void $ ensureProperty $
 		scriptProperty ["service " ++ shellEscape svc ++ " start >/dev/null 2>&1 || true"]
 	return NoChange
 
 restarted :: ServiceName -> Property
-restarted svc = Property ("restarted " ++ svc) $ do
+restarted svc = property ("restarted " ++ svc) $ do
 	void $ ensureProperty $
 		scriptProperty ["service " ++ shellEscape svc ++ " restart >/dev/null 2>&1 || true"]
 	return NoChange
 
 reloaded :: ServiceName -> Property
-reloaded svc = Property ("reloaded " ++ svc) $ do
+reloaded svc = property ("reloaded " ++ svc) $ do
 	void $ ensureProperty $
 		scriptProperty ["service " ++ shellEscape svc ++ " reload >/dev/null 2>&1 || true"]
 	return NoChange
diff --git a/Propellor/Property/SiteSpecific/GitAnnexBuilder.hs b/Propellor/Property/SiteSpecific/GitAnnexBuilder.hs
--- a/Propellor/Property/SiteSpecific/GitAnnexBuilder.hs
+++ b/Propellor/Property/SiteSpecific/GitAnnexBuilder.hs
@@ -40,7 +40,7 @@
 	-- The builduser account does not have a password set,
 	-- instead use the password privdata to hold the rsync server
 	-- password used to upload the built image.
-	, Property "rsync password" $ do
+	, property "rsync password" $ do
 		let f = homedir </> "rsyncpassword"
 		if rsyncupload 
 			then withPrivData (Password builduser) $ \p -> do
diff --git a/Propellor/Property/SiteSpecific/GitHome.hs b/Propellor/Property/SiteSpecific/GitHome.hs
--- a/Propellor/Property/SiteSpecific/GitHome.hs
+++ b/Propellor/Property/SiteSpecific/GitHome.hs
@@ -8,16 +8,16 @@
 -- | Clones Joey Hess's git home directory, and runs its fixups script.
 installedFor :: UserName -> Property
 installedFor user = check (not <$> hasGitDir user) $ 
-	Property ("githome " ++ user) (go =<< liftIO (homedir user))
+	property ("githome " ++ user) (go =<< liftIO (homedir user))
 		`requires` Apt.installed ["git"]
   where
 	go home = do
 		let tmpdir = home </> "githome"
 		ensureProperty $ combineProperties "githome setup"
 			[ userScriptProperty user ["git clone " ++ url ++ " " ++ tmpdir]
-			, Property "moveout" $ makeChange $ void $
+			, property "moveout" $ makeChange $ void $
 				moveout tmpdir home
-			, Property "rmdir" $ makeChange $ void $
+			, property "rmdir" $ makeChange $ void $
 				catchMaybeIO $ removeDirectory tmpdir
 			, userScriptProperty user ["rm -rf .aptitude/ .bashrc .profile; bin/mr checkout; bin/fixups"]
 			]
diff --git a/Propellor/Property/SiteSpecific/JoeySites.hs b/Propellor/Property/SiteSpecific/JoeySites.hs
--- a/Propellor/Property/SiteSpecific/JoeySites.hs
+++ b/Propellor/Property/SiteSpecific/JoeySites.hs
@@ -16,9 +16,63 @@
 import qualified Propellor.Property.Apache as Apache
 import Utility.SafeCommand
 
+import Data.List
+import System.Posix.Files
+
+oldUseNetServer :: [Host] -> Property
+oldUseNetServer hosts = propertyList ("olduse.net server")
+	[ oldUseNetInstalled "oldusenet-server"
+	, Obnam.latestVersion
+	, Obnam.backup datadir "33 4 * * *"
+		[ "--repository=sftp://2318@usw-s002.rsync.net/~/olduse.net"
+		, "--client-name=spool"
+		] Obnam.OnlyClient
+		`requires` Ssh.keyImported SshRsa "root"
+		`requires` Ssh.knownHost hosts "usw-s002.rsync.net" "root"
+	, check (not . isSymbolicLink <$> getSymbolicLinkStatus newsspool) $
+		property "olduse.net spool in place" $ makeChange $ do
+			removeDirectoryRecursive newsspool
+			createSymbolicLink (datadir </> "news") newsspool
+	, Apt.installed ["leafnode"]
+	, "/etc/news/leafnode/config" `File.hasContent` 
+		[ "# olduse.net configuration (deployed by propellor)"
+		, "expire = 1000000" -- no expiry via texpire
+		, "server = " -- no upstream server
+		, "debugmode = 1"
+		, "allowSTRANGERS = 42" -- lets anyone connect
+		, "nopost = 1" -- no new posting (just gather them)
+		]
+	, "/etc/hosts.deny" `File.lacksLine` "leafnode: ALL"
+	, Apt.serviceInstalledRunning "openbsd-inetd"
+	, File.notPresent "/etc/cron.daily/leafnode"
+	, File.notPresent "/etc/cron.d/leafnode"
+	, Cron.niceJob "oldusenet-expire" "11 1 * * *" "news" newsspool $ intercalate ";"
+		[ "find \\( -path ./out.going -or -path ./interesting.groups -or -path './*/.overview' \\) -prune -or -type f -ctime +60  -print | xargs --no-run-if-empty rm"
+		, "find -type d -empty | xargs --no-run-if-empty rmdir"
+		]
+	, Cron.niceJob "oldusenet-uucp" "*/5 * * * *" "news" "/" $
+		"/usr/bin/uucp " ++ datadir
+	, toProp $ Apache.siteEnabled "nntp.olduse.net" $ apachecfg "nntp.olduse.net" False
+		[ "  DocumentRoot " ++ datadir ++ "/"
+		, "  <Directory " ++ datadir ++ "/>"
+		, "    Options Indexes FollowSymlinks"
+		, "    AllowOverride None"
+		-- I had this in the file before.
+		-- This may be needed by a newer version of apache?
+		--, "    Require all granted"
+		, "  </Directory>"
+		]
+	]
+  where
+	newsspool = "/var/spool/news"
+	datadir = "/var/spool/oldusenet"
+
 oldUseNetShellBox :: Property
-oldUseNetShellBox = check (not <$> Apt.isInstalled "oldusenet") $
-	propertyList ("olduse.net shellbox")
+oldUseNetShellBox = oldUseNetInstalled "oldusenet"
+
+oldUseNetInstalled :: Apt.Package -> Property
+oldUseNetInstalled pkg = check (not <$> Apt.isInstalled pkg) $
+	propertyList ("olduse.net " ++ pkg)
 		[ Apt.installed (words "build-essential devscripts debhelper git libncursesw5-dev libpcre3-dev pkg-config bison libicu-dev libidn11-dev libcanlock2-dev libuu-dev ghc libghc-strptime-dev libghc-hamlet-dev libghc-ifelse-dev libghc-hxt-dev libghc-utf8-string-dev libghc-missingh-dev libghc-sha-dev")
 			`describe` "olduse.net build deps"
 		, scriptProperty
@@ -26,12 +80,13 @@
 			, "git clone git://olduse.net/ /root/tmp/oldusenet/source"
 			, "cd /root/tmp/oldusenet/source/"
 			, "dpkg-buildpackage -us -uc"
-			, "dpkg -i ../oldusenet*.deb || true"
+			, "dpkg -i ../" ++ pkg ++ "_*.deb || true"
 			, "apt-get -fy install" -- dependencies
 			, "rm -rf /root/tmp/oldusenet"
 			] `describe` "olduse.net built"
 		]
 
+
 kgbServer :: Property
 kgbServer = withOS desc $ \o -> case o of
 	(Just (System (Debian Unstable) _)) ->
@@ -50,7 +105,8 @@
 -- git.kitenet.net and git.joeyh.name
 gitServer :: [Host] -> Property
 gitServer hosts = propertyList "git.kitenet.net setup"
-	[ Obnam.backup "/srv/git" "33 3 * * *"
+	[ Obnam.latestVersion
+	, Obnam.backup "/srv/git" "33 3 * * *"
 		[ "--repository=sftp://2318@usw-s002.rsync.net/~/git.kitenet.net"
 		, "--encrypt-with=1B169BE1"
 		, "--client-name=wren"
diff --git a/Propellor/Property/Ssh.hs b/Propellor/Property/Ssh.hs
--- a/Propellor/Property/Ssh.hs
+++ b/Propellor/Property/Ssh.hs
@@ -67,7 +67,7 @@
 randomHostKeys = flagFile prop "/etc/ssh/.unique_host_keys"
 	`onChange` restartSshd
   where
-	prop = Property "ssh random host keys" $ do
+	prop = property "ssh random host keys" $ do
 		void $ liftIO $ boolSystem "sh"
 			[ Param "-c"
 			, Param "rm -f /etc/ssh/ssh_host_*"
@@ -81,8 +81,8 @@
 -- (Uses a null username for host keys.)
 hostKey :: SshKeyType -> Property
 hostKey keytype = combineProperties desc
-	[ Property desc (install writeFile (SshPubKey keytype "") ".pub")
-	, Property desc (install writeFileProtected (SshPrivKey keytype "") "")
+	[ property desc (install writeFile (SshPubKey keytype "") ".pub")
+	, property desc (install writeFileProtected (SshPrivKey keytype "") "")
 	]
 	`onChange` restartSshd
   where
@@ -98,8 +98,8 @@
 -- from the site's PrivData.
 keyImported :: SshKeyType -> UserName -> Property
 keyImported keytype user = combineProperties desc
-	[ Property desc (install writeFile (SshPubKey keytype user) ".pub")
-	, Property desc (install writeFileProtected (SshPrivKey keytype user) "")
+	[ property desc (install writeFile (SshPubKey keytype user) ".pub")
+	, property desc (install writeFileProtected (SshPrivKey keytype user) "")
 	]
   where
 	desc = user ++ " has ssh key (" ++ fromKeyType keytype ++ ")"
@@ -108,7 +108,7 @@
 		ifM (liftIO $ doesFileExist f)
 			( noChange
 			, ensureProperty $ combineProperties desc
-				[ Property desc $ 
+				[ property desc $ 
 					withPrivData p $ \key -> makeChange $
 						writer f key
 				, File.ownerGroup f user user
@@ -126,7 +126,7 @@
 
 -- | Puts some host's ssh public key into the known_hosts file for a user.
 knownHost :: [Host] -> HostName -> UserName -> Property
-knownHost hosts hn user = Property desc $
+knownHost hosts hn user = property desc $
 	go =<< fromHost hosts hn getSshPubKey
   where
 	desc = user ++ " knows ssh key for " ++ hn
@@ -143,7 +143,7 @@
 
 -- | Makes a user have authorized_keys from the PrivData
 authorizedKeys :: UserName -> Property
-authorizedKeys user = Property (user ++ " has authorized_keys") $
+authorizedKeys user = property (user ++ " has authorized_keys") $
 	withPrivData (SshAuthorizedKeys user) $ \v -> do
 		f <- liftIO $ dotFile "authorized_keys" user
 		liftIO $ do
diff --git a/Propellor/Property/Sudo.hs b/Propellor/Property/Sudo.hs
--- a/Propellor/Property/Sudo.hs
+++ b/Propellor/Property/Sudo.hs
@@ -10,7 +10,7 @@
 -- | 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
-enabledFor user = Property desc go `requires` Apt.installed ["sudo"]
+enabledFor user = property desc go `requires` Apt.installed ["sudo"]
   where
 	go = do
 		locked <- liftIO $ isLockedPassword user
diff --git a/Propellor/Property/User.hs b/Propellor/Property/User.hs
--- a/Propellor/Property/User.hs
+++ b/Propellor/Property/User.hs
@@ -29,7 +29,7 @@
 	hasPassword user
 
 hasPassword :: UserName -> Property
-hasPassword user = Property (user ++ " has password") $
+hasPassword user = property (user ++ " has password") $
 	withPrivData (Password user) $ \password -> makeChange $
 		withHandle StdinHandle createProcessSuccess
 			(proc "chpasswd" []) $ \h -> do
diff --git a/Propellor/Types.hs b/Propellor/Types.hs
--- a/Propellor/Types.hs
+++ b/Propellor/Types.hs
@@ -5,15 +5,13 @@
 module Propellor.Types
 	( Host(..)
 	, Attr
-	, HostName
 	, Propellor(..)
 	, Property(..)
 	, RevertableProperty(..)
-	, AttrProperty(..)
 	, IsProp
 	, describe
 	, toProp
-	, getAttr
+	, setAttr
 	, requires
 	, Desc
 	, Result(..)
@@ -23,6 +21,7 @@
 	, GpgKeyId
 	, SshKeyType(..)
 	, module Propellor.Types.OS
+	, module Propellor.Types.Dns
 	) where
 
 import Data.Monoid
@@ -33,8 +32,9 @@
 
 import Propellor.Types.Attr
 import Propellor.Types.OS
+import Propellor.Types.Dns
 
-data Host = Host [Property] (Attr -> Attr)
+data Host = Host [Property] SetAttr
 
 -- | Propellor's monad provides read-only access to attributes of the
 -- system.
@@ -53,16 +53,15 @@
 -- property.
 data Property = Property
 	{ propertyDesc :: Desc
-	-- | must be idempotent; may run repeatedly
 	, propertySatisfy :: Propellor Result
+	-- ^ must be idempotent; may run repeatedly
+	, propertyAttr :: SetAttr
+	-- ^ a property can affect the overall Attr
 	}
 
 -- | A property that can be reverted.
 data RevertableProperty = RevertableProperty Property Property
 
--- | A property that affects the Attr.
-data AttrProperty = forall p. IsProp p => AttrProperty p (Attr -> Attr)
-
 class IsProp p where
 	-- | Sets description.
 	describe :: p -> Desc -> p
@@ -70,17 +69,21 @@
 	-- | Indicates that the first property can only be satisfied
 	-- once the second one is.
 	requires :: p -> Property -> p
-	getAttr :: p -> (Attr -> Attr)
+	setAttr :: p -> SetAttr
 
 instance IsProp Property where
 	describe p d = p { propertyDesc = d }
 	toProp p = p
-	x `requires` y = Property (propertyDesc x) $ do
-		r <- propertySatisfy y
-		case r of
-			FailedChange -> return FailedChange
-			_ -> propertySatisfy x
-	getAttr _ = id
+	setAttr = propertyAttr
+	x `requires` y = Property (propertyDesc x) satisfy attr
+	  where
+	  	attr = propertyAttr x . propertyAttr y
+		satisfy = do
+			r <- propertySatisfy y
+			case r of
+				FailedChange -> return FailedChange
+				_ -> propertySatisfy x
+			
 
 instance IsProp RevertableProperty where
 	-- | Sets the description of both sides.
@@ -89,13 +92,8 @@
 	toProp (RevertableProperty p1 _) = p1
 	(RevertableProperty p1 p2) `requires` y =
 		RevertableProperty (p1 `requires` y) p2
-	getAttr _ = id
-
-instance IsProp AttrProperty where
-	describe (AttrProperty p a) d = AttrProperty (describe p d) a
-	toProp (AttrProperty p _) = toProp p
-	(AttrProperty p a) `requires` y = AttrProperty (p `requires` y) a
-	getAttr (AttrProperty _ a) = a
+	-- | Return the SetAttr of the currently active side.
+	setAttr (RevertableProperty p1 _p2) = setAttr p1
 
 type Desc = String
 
diff --git a/Propellor/Types/Attr.hs b/Propellor/Types/Attr.hs
--- a/Propellor/Types/Attr.hs
+++ b/Propellor/Types/Attr.hs
@@ -1,15 +1,18 @@
 module Propellor.Types.Attr where
 
 import Propellor.Types.OS
+import qualified Propellor.Types.Dns as Dns
 
 import qualified Data.Set as S
+import qualified Data.Map as M
 
 -- | The attributes of a host. For example, its hostname.
 data Attr = Attr
 	{ _hostname :: HostName
-	, _cnames :: S.Set Domain
 	, _os :: Maybe System
 	, _sshPubKey :: Maybe String
+	, _dns :: S.Set Dns.Record
+	, _namedconf :: M.Map Dns.Domain Dns.NamedConf
 
 	, _dockerImage :: Maybe String
 	, _dockerRunParams :: [HostName -> String]
@@ -18,8 +21,9 @@
 instance Eq Attr where
 	x == y = and
 		[ _hostname x == _hostname y
-		, _cnames x == _cnames y
 		, _os x == _os y
+		, _dns x == _dns y
+		, _namedconf x == _namedconf y
 		, _sshPubKey x == _sshPubKey y
 
 		, _dockerImage x == _dockerImage y
@@ -30,15 +34,15 @@
 instance Show Attr where
 	show a = unlines
 		[ "hostname " ++ _hostname a
-		, "cnames " ++ show (_cnames a)
 		, "OS " ++ show (_os a)
 		, "sshPubKey " ++ show (_sshPubKey a)
+		, "dns " ++ show (_dns a)
+		, "namedconf " ++ show (_namedconf a)
 		, "docker image " ++ show (_dockerImage a)
 		, "docker run params " ++ show (map (\mk -> mk "") (_dockerRunParams a))
 		]
 
 newAttr :: HostName -> Attr
-newAttr hn = Attr hn S.empty Nothing Nothing Nothing []
+newAttr hn = Attr hn Nothing Nothing S.empty M.empty Nothing []
 
-type HostName = String
-type Domain = String
+type SetAttr = Attr -> Attr
diff --git a/Propellor/Types/Dns.hs b/Propellor/Types/Dns.hs
new file mode 100644
--- /dev/null
+++ b/Propellor/Types/Dns.hs
@@ -0,0 +1,81 @@
+module Propellor.Types.Dns where
+
+import Data.Word
+
+type Domain = String
+
+data IPAddr = IPv4 String | IPv6 String
+	deriving (Read, Show, Eq, Ord)
+
+fromIPAddr :: IPAddr -> String
+fromIPAddr (IPv4 addr) = addr
+fromIPAddr (IPv6 addr) = addr
+
+-- | Represents a bind 9 named.conf file.
+data NamedConf = NamedConf
+	{ confDomain :: Domain
+	, confType :: Type
+	, confFile :: FilePath
+	, confMasters :: [IPAddr]
+	, confLines :: [String]
+	}
+	deriving (Show, Eq, Ord)
+
+data Type = Master | Secondary
+	deriving (Show, Eq, Ord)
+
+-- | Represents a bind 9 zone file.
+data Zone = Zone
+	{ zDomain :: Domain
+	, zSOA :: SOA
+	, zHosts :: [(BindDomain, Record)]
+	}
+	deriving (Read, Show, Eq)
+
+-- | Every domain has a SOA record, which is big and complicated.
+data SOA = SOA
+	{ sDomain :: BindDomain
+	-- ^ Typically ns1.your.domain
+	, sSerial :: SerialNumber
+	-- ^ The most important parameter is the serial number,
+	-- which must increase after each change.
+	, sRefresh :: Integer
+	, sRetry :: Integer
+	, sExpire :: Integer
+	, sNegativeCacheTTL :: Integer
+	, sRecord :: [Record]
+	-- ^ Records for the root of the domain. Typically NS, A, TXT
+	}
+	deriving (Read, Show, Eq)
+
+-- | Types of DNS records.
+--
+-- This is not a complete list, more can be added.
+data Record
+	= Address IPAddr
+	| CNAME BindDomain
+	| MX Int BindDomain
+	| NS BindDomain
+	| TXT String
+	| SRV Word16 Word16 Word16 BindDomain
+	deriving (Read, Show, Eq, Ord)
+
+getIPAddr :: Record -> Maybe IPAddr
+getIPAddr (Address addr) = Just addr
+getIPAddr _ = Nothing
+
+getCNAME :: Record -> Maybe BindDomain
+getCNAME (CNAME d) = Just d
+getCNAME _ = Nothing
+
+-- | Bind serial numbers are unsigned, 32 bit integers.
+type SerialNumber = Word32
+
+-- | Domains in the zone file must end with a period if they are absolute.
+--
+-- Let's use a type to keep absolute domains straight from relative
+-- domains.
+--
+-- The SOADomain refers to the root SOA record.
+data BindDomain = RelDomain Domain | AbsDomain Domain | SOADomain
+	deriving (Read, Show, Eq, Ord)
diff --git a/Propellor/Types/OS.hs b/Propellor/Types/OS.hs
--- a/Propellor/Types/OS.hs
+++ b/Propellor/Types/OS.hs
@@ -1,5 +1,6 @@
 module Propellor.Types.OS where
 
+type HostName = String
 type UserName = String
 type GroupName = String
 
diff --git a/TODO b/TODO
--- a/TODO
+++ b/TODO
@@ -15,7 +15,12 @@
 * There is no way for a property of a docker container to require
   some property be met outside the container. For example, some servers
   need ntp installed for a good date source.
-* Attributes can only be set in the top level property list for a Host.
-  If an attribute is set inside a propertyList, it won't propigate out.
-  Fix this. Probably the fix involves combining AttrProperty into Property.
-  Then propertyList can gather the attributes from its list.
+* Docking a container in a host should add to the host any cnames that
+  are assigned to the container.
+* Either `Ssh.hostKey` should set the sshPubKey attr
+  (which seems hard, as attrs need to be able to be calculated without
+  running any IO code, and here IO is needed along with decrypting the
+  PrivData..), or the public key should not be stored in
+  the PrivData, and instead configured using the attr.
+  Getting the ssh host key into the attr will allow automatically
+  exporting it via DNS (SSHFP record)
diff --git a/config-joey.hs b/config-joey.hs
--- a/config-joey.hs
+++ b/config-joey.hs
@@ -32,11 +32,15 @@
 hosts =               --                  (o)  `
 	-- My laptop
 	[ host "darkstar.kitenet.net"
+		& ipv6 "2001:4830:1600:187::2" -- sixxs tunnel
 		& Docker.configured
 		& Apt.buildDep ["git-annex"] `period` Daily
 
 	-- Nothing super-important lives here.
 	, standardSystem "clam.kitenet.net" Unstable "amd64"
+		& ipv4 "162.248.143.249"
+		& ipv6 "2002:5044:5531::1"
+
 		& cleanCloudAtCost
 		& Apt.unattendedUpgrades
 		& Network.ipv6to4
@@ -44,18 +48,18 @@
 		& Postfix.satellite
 		& Docker.configured
 
-		& cname "shell.olduse.net"
+		& alias "shell.olduse.net"
 		& JoeySites.oldUseNetShellBox
 
-		& cname "openid.kitenet.net"
+		& alias "openid.kitenet.net"
 		& Docker.docked hosts "openid-provider"
 		 	`requires` Apt.installed ["ntp"]
 
-		& cname "ancient.kitenet.net"
+		& alias "ancient.kitenet.net"
 		& Docker.docked hosts "ancient-kitenet"
 
 		-- I'd rather this were on diatom, but it needs unstable.
-		& cname "kgb.kitenet.net"
+		& alias "kgb.kitenet.net"
 		& JoeySites.kgbServer
 
 		& Docker.garbageCollected `period` Daily
@@ -63,6 +67,8 @@
 	
 	-- Orca is the main git-annex build box.
 	, standardSystem "orca.kitenet.net" Unstable "amd64"
+		& ipv4 "138.38.108.179"
+
 		& Hostname.sane
 		& Apt.unattendedUpgrades
 		& Postfix.satellite
@@ -76,13 +82,14 @@
 	
 	-- Important stuff that needs not too much memory or CPU.
   	, standardSystem "diatom.kitenet.net" Stable "amd64"
+		& ipv4 "107.170.31.195"
+
 		& Hostname.sane
 		& Ssh.hostKey SshDsa
 		& Ssh.hostKey SshRsa
 		& Ssh.hostKey SshEcdsa
 		& Apt.unattendedUpgrades
 		& Apt.serviceInstalledRunning "ntp"
-		& Dns.zones myDnsSecondary
 		& Postfix.satellite
 	
 		& Apt.serviceInstalledRunning "apache2"
@@ -93,24 +100,40 @@
 		& Apache.multiSSL
 		& File.ownerGroup "/srv/web" "joey" "joey"
 
-		& cname "git.kitenet.net"
-		& cname "git.joeyh.name"
+		& alias "git.kitenet.net"
+		& alias "git.joeyh.name"
 		& JoeySites.gitServer hosts
 	
-		& cname "downloads.kitenet.net"
+		& alias "downloads.kitenet.net"
 		& JoeySites.annexWebSite hosts "/srv/git/downloads.git"
 			"downloads.kitenet.net"
 			"840760dc-08f0-11e2-8c61-576b7e66acfd"
 			[("turtle", "ssh://turtle.kitenet.net/~/lib/downloads/")]
 		& JoeySites.annexRsyncServer
 
-		& cname "tmp.kitenet.net"
+		& alias "tmp.kitenet.net"
 		& JoeySites.annexWebSite hosts "/srv/git/joey/tmp.git"
 			"tmp.kitenet.net"
 			"26fd6e38-1226-11e2-a75f-ff007033bdba"
 			[]
 		& JoeySites.twitRss
 		
+		& alias "nntp.olduse.net"
+		& alias "resources.olduse.net"
+		& JoeySites.oldUseNetServer hosts
+		
+		& myDnsSecondary
+		& Dns.primary hosts "olduse.net"
+			( Dns.mkSOA "ns1.kitenet.net" 100
+				[ NS (AbsDomain "ns1.kitenet.net")
+				, NS (AbsDomain "ns6.gandi.net")
+				, NS (AbsDomain "ns2.kitenet.net")
+				, MX 0 (AbsDomain "kitenet.net")
+				, TXT "v=spf1 a -all"
+				]
+			)
+			[ (RelDomain "article", CNAME $ AbsDomain "virgil.koldfront.dk") ]
+
 		& Apt.installed ["ntop"]
 
 
@@ -171,7 +194,8 @@
 standardSystem :: HostName -> DebianSuite -> Architecture -> Host
 standardSystem hn suite arch = host hn
 	& os (System (Debian suite) arch)
-	& Apt.stdSourcesList suite `onChange` Apt.upgrade
+	& Apt.stdSourcesList suite
+		`onChange` Apt.upgrade
 	& Apt.installed ["etckeeper"]
 	& Apt.installed ["ssh"]
 	& GitHome.installedFor "root"
@@ -221,17 +245,17 @@
 		]
 	]
 
-myDnsSecondary :: [Dns.Zone]
-myDnsSecondary =
-	[ Dns.secondary "kitenet.net" master
-	, Dns.secondary "joeyh.name" master
-	, Dns.secondary "ikiwiki.info" master
-	, Dns.secondary "olduse.net" master
-	, Dns.secondary "branchable.com" branchablemaster
+myDnsSecondary :: Property
+myDnsSecondary = propertyList "dns secondary for all my domains"
+	[ Dns.secondaryFor wren hosts "kitenet.net"
+	, Dns.secondaryFor wren hosts "joeyh.name"
+	, Dns.secondaryFor wren hosts "ikiwiki.info"
+	, Dns.secondary hosts "olduse.net"
+	, Dns.secondaryFor branchable hosts "branchable.com"
 	]
   where
-	master = ["80.68.85.49", "2001:41c8:125:49::10"] -- wren
-	branchablemaster = ["66.228.46.55", "2600:3c03::f03c:91ff:fedf:c0e5"]
+	wren = ["wren.kitenet.net"]
+	branchable = ["branchable.com"]
 
 main :: IO ()
 main = defaultMain hosts
@@ -250,11 +274,23 @@
 
 
 monsters :: [Host]    -- Systems I don't manage with propellor,
-monsters =	      -- but do want to track their public keys.
+monsters =	      -- but do want to track their public keys etc.
 	[ host "usw-s002.rsync.net"
 		& sshPubKey "ssh-dss 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"
-	, host "turtle.kitenet.net"
-		& sshPubKey "ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAokMXQiX/NZjA1UbhMdgAscnS5dsmy+Q7bWrQ6tsTZ/o+6N/T5cbjoBHOdpypXJI3y/PiJTDJaQtXIhLa8gFg/EvxMnMz/KG9skADW1361JmfCc4BxicQIO2IOOe6eilPr+YsnOwiHwL0vpUnuty39cppuMWVD25GzxXlS6KQsLCvXLzxLLuNnGC43UAM0q4UwQxDtAZEK1dH2o3HMWhgMP2qEQupc24dbhpO3ecxh2C9678a3oGDuDuNf7mLp3s7ptj5qF3onitpJ82U5o7VajaHoygMaSRFeWxP2c13eM57j3bLdLwxVXFhePcKXARu1iuFTLS5uUf3hN6MkQcOGw=="
 	, host "github.com" 
 		& sshPubKey "ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ=="
+	, host "turtle.kitenet.net"
+		& ipv4 "67.223.19.96"
+		& ipv6 "2001:4978:f:2d9::2"
+		& sshPubKey "ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAokMXQiX/NZjA1UbhMdgAscnS5dsmy+Q7bWrQ6tsTZ/o+6N/T5cbjoBHOdpypXJI3y/PiJTDJaQtXIhLa8gFg/EvxMnMz/KG9skADW1361JmfCc4BxicQIO2IOOe6eilPr+YsnOwiHwL0vpUnuty39cppuMWVD25GzxXlS6KQsLCvXLzxLLuNnGC43UAM0q4UwQxDtAZEK1dH2o3HMWhgMP2qEQupc24dbhpO3ecxh2C9678a3oGDuDuNf7mLp3s7ptj5qF3onitpJ82U5o7VajaHoygMaSRFeWxP2c13eM57j3bLdLwxVXFhePcKXARu1iuFTLS5uUf3hN6MkQcOGw=="
+	, host "wren.kitenet.net"
+		& ipv4 "80.68.85.49"
+		& ipv6 "2001:41c8:125:49::10"
+		& alias "kite.kitenet.net"
+	, host "branchable.com"
+		& ipv4 "66.228.46.55"
+		& ipv6 "2600:3c03::f03c:91ff:fedf:c0e5"
+		& alias "olduse.net"
+		& alias "www.olduse.net"
+		& alias "git.olduse.net"
 	]
diff --git a/debian/changelog b/debian/changelog
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,18 @@
+propellor (0.4.0) unstable; urgency=medium
+
+  * Propellor can configure primary DNS servers, including generating
+    zone files, which is done by looking at the properties of hosts
+    in a domain.
+  * The `cname` property was renamed to `alias` as it does not always
+    generate CNAME in the DNS.
+  * Constructor of Property has changed (use `property` function instead).
+  * All Property combinators now combine together their Attr settings.
+    So Attr settings can be made inside a propertyList, for example.
+  * Run all cron jobs under chronic from moreutils to avoid unnecessary
+    mails.
+
+ -- Joey Hess <joeyh@debian.org>  Sat, 19 Apr 2014 02:09:56 -0400
+
 propellor (0.3.1) unstable; urgency=medium
 
   * Merge scheduler bug fix from git-annex.
diff --git a/propellor.cabal b/propellor.cabal
--- a/propellor.cabal
+++ b/propellor.cabal
@@ -1,5 +1,5 @@
 Name: propellor
-Version: 0.3.1
+Version: 0.4.0
 Cabal-Version: >= 1.6
 License: GPL
 Maintainer: Joey Hess <joey@kitenet.net>
@@ -99,6 +99,7 @@
     Propellor.Exception
     Propellor.Types
     Propellor.Types.OS
+    Propellor.Types.Dns
   Other-Modules:
     Propellor.Types.Attr
     Propellor.CmdLine