starting work on a Chroot module

factored out info up-propigation code rom Docker

1 files changed, 57 insertions, 0 deletions

diff --git a/src/Propellor/Property/Chroot.hs b/src/Propellor/Property/Chroot.hs
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+++ b/src/Propellor/Property/Chroot.hs
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+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