change HostContext for containers

Privdata that uses HostContext inside a container will now have the name of
the container as its context, rather than the name of the host(s) where the
container is used. This allows eg, having different passwords for a user in
different containers.

Note that previously, propellor would prompt using
the container name as the context, but not actually use privdata using that
context; so this is a bug fix.

I don't entirely like the implementation; I had to put the code to change
the context in PropAccum, and it's not generalized past PrivInfo.

6 files changed, 34 insertions, 10 deletions

diff --git a/src/Propellor/PrivData.hs b/src/Propellor/PrivData.hs
index 5df9fe0d..0019730d 100644
--- a/src/Propellor/PrivData.hs
+++ b/src/Propellor/PrivData.hs
@@ -17,6 +17,7 @@ module Propellor.PrivData (
 	decryptPrivData,
 	PrivMap,
 	PrivInfo,
+	forceHostContext,
 ) where
 
 import Control.Applicative
@@ -236,3 +237,10 @@ newtype PrivInfo = PrivInfo
 -- hosts need it.
 instance IsInfo PrivInfo where
 	propigateInfo _ = True
+
+-- | Sets the context of any privdata that uses HostContext to the
+-- provided name.
+forceHostContext :: String -> PrivInfo -> PrivInfo
+forceHostContext name i = PrivInfo $ S.map go (fromPrivInfo i)
+  where
+	go (f, d, HostContext ctx) = (f, d, HostContext (const $ ctx name)) 
diff --git a/src/Propellor/PropAccum.hs b/src/Propellor/PropAccum.hs
index 4b2a5ddb..dec204a2 100644
--- a/src/Propellor/PropAccum.hs
+++ b/src/Propellor/PropAccum.hs
@@ -14,6 +14,7 @@ import Data.Monoid
 import Propellor.Types
 import Propellor.Property
 import Propellor.Types.Info
+import Propellor.PrivData
 
 -- | Starts accumulating the properties of a Host.
 --
@@ -72,12 +73,16 @@ infixl 1 !
 -- 
 -- The Info of the propertyChildren is adjusted to only include 
 -- info that should be propigated out to the Property.
+--
+-- Any PrivInfo that uses HostContext is adjusted to use the name
+-- of the container as its context.
 propigateContainer
 	:: (PropAccum container)
-	=> container
+	=> String
+	-> container
 	-> Property HasInfo
 	-> Property HasInfo
-propigateContainer c prop = infoProperty
+propigateContainer containername c prop = infoProperty
 	(propertyDesc prop)
 	(propertySatisfy prop)
 	(propertyInfo prop)
@@ -85,6 +90,7 @@ propigateContainer c prop = infoProperty
   where
 	hostprops = map go $ getProperties c
 	go p = 
-		let i = propigatableInfo (propertyInfo p)
+		let i = mapInfo (forceHostContext containername)
+			(propigatableInfo (propertyInfo p))
 		    cs = map go (propertyChildren p)
 		in infoProperty (propertyDesc p) (propertySatisfy p) i cs
diff --git a/src/Propellor/Property/Chroot.hs b/src/Propellor/Property/Chroot.hs
index 0cbc8642..b059e3eb 100644
--- a/src/Propellor/Property/Chroot.hs
+++ b/src/Propellor/Property/Chroot.hs
@@ -83,7 +83,7 @@ provisioned' propigator c@(Chroot loc system builderconf _) systemdonly =
 	teardown = toProp (revert built)
 
 propigateChrootInfo :: (IsProp (Property i)) => Chroot -> Property i -> Property HasInfo
-propigateChrootInfo c p = propigateContainer c p'
+propigateChrootInfo c@(Chroot location _ _ _) p = propigateContainer location c p'
   where
 	p' = infoProperty
 		(propertyDesc p)
diff --git a/src/Propellor/Property/Docker.hs b/src/Propellor/Property/Docker.hs
index 9cfc24b6..e6365276 100644
--- a/src/Propellor/Property/Docker.hs
+++ b/src/Propellor/Property/Docker.hs
@@ -19,7 +19,7 @@ module Propellor.Property.Docker (
 	Image(..),
 	latestImage,
 	ContainerName,
-	Container,
+	Container(..),
 	HasImage(..),
 	-- * Container configuration
 	dns,
@@ -171,7 +171,7 @@ imagePulled ctr = describe pulled msg
 	image = getImageName ctr
 
 propigateContainerInfo :: (IsProp (Property i)) => Container -> Property i -> Property HasInfo
-propigateContainerInfo ctr@(Container _ h) p = propigateContainer ctr p'
+propigateContainerInfo ctr@(Container _ h) p = propigateContainer cn ctr p'
   where
 	p' = infoProperty
 		(propertyDesc p)
@@ -179,7 +179,8 @@ propigateContainerInfo ctr@(Container _ h) p = propigateContainer ctr p'
 		(propertyInfo p <> dockerinfo)
 		(propertyChildren p)
 	dockerinfo = dockerInfo $
-		mempty { _dockerContainers = M.singleton (hostName h) h }
+		mempty { _dockerContainers = M.singleton cn h }
+	cn = hostName h
 
 mkContainerInfo :: ContainerId -> Container -> ContainerInfo
 mkContainerInfo cid@(ContainerId hn _cn) (Container img h) = 
diff --git a/src/Propellor/Types/Info.hs b/src/Propellor/Types/Info.hs
index a80bb681..347a03e7 100644
--- a/src/Propellor/Types/Info.hs
+++ b/src/Propellor/Types/Info.hs
@@ -5,6 +5,7 @@ module Propellor.Types.Info (
 	IsInfo(..),
 	addInfo,
 	getInfo,
+	mapInfo,
 	propigatableInfo,
 	InfoVal(..),
 	fromInfoVal,
@@ -16,8 +17,6 @@ import Data.Monoid
 import Data.Maybe
 
 -- | Information about a Host, which can be provided by its properties.
---
--- Any value in the `IsInfo` type class can be added to an Info.
 data Info = Info [(Dynamic, Bool)]
 
 instance Show Info where
@@ -37,12 +36,22 @@ class (Typeable v, Monoid v) => IsInfo v where
 	-- container to its Host?
 	propigateInfo :: v -> Bool
 
+-- | Any value in the `IsInfo` type class can be added to an Info.
 addInfo :: IsInfo v => Info -> v -> Info
 addInfo (Info l) v = Info ((toDyn v, propigateInfo v):l)
 
 getInfo :: IsInfo v => Info -> v
 getInfo (Info l) = mconcat (mapMaybe (fromDynamic . fst) (reverse l))
 
+-- | Maps a function over all values stored in the Info that are of the
+-- appropriate type.
+mapInfo :: IsInfo v => (v -> v) -> Info -> Info
+mapInfo f (Info l) = Info (map go l)
+  where
+	go (i, p) = case fromDynamic i of
+		Nothing -> (i, p)
+		Just v -> (toDyn (f v), p)
+
 -- | Filters out parts of the Info that should not propigate out of a
 -- container.
 propigatableInfo :: Info -> Info
diff --git a/src/Propellor/Types/PrivData.hs b/src/Propellor/Types/PrivData.hs
index 98cdb7a1..1cf22aa9 100644
--- a/src/Propellor/Types/PrivData.hs
+++ b/src/Propellor/Types/PrivData.hs
@@ -61,7 +61,7 @@ instance IsPrivDataSource PrivDataSource where
 newtype Context = Context String
 	deriving (Read, Show, Ord, Eq)
 
--- | A context that varies depending on the HostName where it's used.
+-- | A context that may vary depending on the HostName where it's used.
 newtype HostContext = HostContext { mkHostContext :: HostName -> Context }
 
 instance Show HostContext where