{-# LANGUAGE PackageImports #-} {-# LANGUAGE GeneralizedNewtypeDeriving #-} {-# LANGUAGE GADTs #-} {-# LANGUAGE EmptyDataDecls #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE TypeFamilies #-} module Propellor.Types ( Host(..) , Desc , Property , HasInfo , NoInfo , CInfo , infoProperty , simpleProperty , adjustPropertySatisfy , propertyInfo , propertyDesc , propertyChildren , RevertableProperty(..) , () , IsProp(..) , Combines(..) , CombinedType , before , combineWith , Info(..) , Propellor(..) , EndAction(..) , module Propellor.Types.OS , module Propellor.Types.Dns , module Propellor.Types.Result , propertySatisfy , ignoreInfo ) where import Data.Monoid import Control.Applicative import "mtl" Control.Monad.RWS.Strict import "MonadCatchIO-transformers" Control.Monad.CatchIO import qualified Data.Set as S import qualified Data.Map as M import Propellor.Types.OS import Propellor.Types.Chroot import Propellor.Types.Dns import Propellor.Types.Docker import Propellor.Types.PrivData import Propellor.Types.Empty import Propellor.Types.Val import Propellor.Types.Result import qualified Propellor.Types.Dns as Dns -- | Everything Propellor knows about a system: Its hostname, -- properties and their collected info. data Host = Host { hostName :: HostName , hostProperties :: [Property HasInfo] , hostInfo :: Info } deriving (Show) -- | Propellor's monad provides read-only access to info about the host -- it's running on, and a writer to accumulate EndActions. newtype Propellor p = Propellor { runWithHost :: RWST Host [EndAction] () IO p } deriving ( Monad , Functor , Applicative , MonadReader Host , MonadWriter [EndAction] , MonadIO , MonadCatchIO ) instance Monoid (Propellor Result) where mempty = return NoChange -- | The second action is only run if the first action does not fail. mappend x y = do rx <- x case rx of FailedChange -> return FailedChange _ -> do ry <- y return (rx <> ry) -- | An action that Propellor runs at the end, after trying to satisfy all -- properties. It's passed the combined Result of the entire Propellor run. data EndAction = EndAction Desc (Result -> Propellor Result) type Desc = String -- | The core data type of Propellor, this represents a property -- that the system should have, and an action to ensure it has the -- property. data Property i where IProperty :: Desc -> Propellor Result -> Info -> [Property HasInfo] -> Property HasInfo SProperty :: Desc -> Propellor Result -> [Property NoInfo] -> Property NoInfo -- | Indicates that a Property has associated Info. data HasInfo -- | Indicates that a Property does not have Info. data NoInfo -- | Type level calculation of the combination of HasInfo and/or NoInfo type family CInfo x y type instance CInfo HasInfo HasInfo = HasInfo type instance CInfo HasInfo NoInfo = HasInfo type instance CInfo NoInfo HasInfo = HasInfo type instance CInfo NoInfo NoInfo = NoInfo -- | Constructs a Property with associated Info. infoProperty :: Desc -- ^ description of the property -> Propellor Result -- ^ action to run to satisfy the property (must be idempotent; may run repeatedly) -> Info -- ^ info associated with the property -> [Property i] -- ^ child properties -> Property HasInfo infoProperty d a i cs = IProperty d a i (map toIProperty cs) -- | Constructs a Property with no Info. simpleProperty :: Desc -> Propellor Result -> [Property NoInfo] -> Property NoInfo simpleProperty = SProperty toIProperty :: Property i -> Property HasInfo toIProperty p@(IProperty {}) = p toIProperty (SProperty d s cs) = IProperty d s mempty (map toIProperty cs) toSProperty :: Property i -> Property NoInfo toSProperty (IProperty d s _ cs) = SProperty d s (map toSProperty cs) toSProperty p@(SProperty {}) = p -- | Makes a version of a Proprty without its Info. -- Use with caution! ignoreInfo :: Property i -> Property NoInfo ignoreInfo = toSProperty -- | Gets the action that can be run to satisfy a Property. -- You should never run this action directly. Use -- 'Propellor.Engine.ensureProperty` instead. propertySatisfy :: Property i -> Propellor Result propertySatisfy (IProperty _ a _ _) = a propertySatisfy (SProperty _ a _) = a instance Show (Property i) where show p = "property " ++ show (propertyDesc p) -- | Changes the action that is performed to satisfy a property. adjustPropertySatisfy :: Property i -> (Propellor Result -> Propellor Result) -> Property i adjustPropertySatisfy (IProperty d s i cs) f = IProperty d (f s) i cs adjustPropertySatisfy (SProperty d s cs) f = SProperty d (f s) cs propertyInfo :: Property i -> Info propertyInfo (IProperty _ _ i _) = i propertyInfo (SProperty {}) = mempty propertyDesc :: Property i -> Desc propertyDesc (IProperty d _ _ _) = d propertyDesc (SProperty d _ _) = d -- | A Property can include a list of child properties that it also -- satisfies. This allows them to be introspected to collect their info, etc. propertyChildren :: Property i -> [Property i] propertyChildren (IProperty _ _ _ cs) = cs propertyChildren (SProperty _ _ cs) = cs -- | A property that can be reverted. data RevertableProperty = RevertableProperty (Property HasInfo) (Property HasInfo) -- | Makes a revertable property; the first Property is run -- normally and the second is run when it's reverted. () :: Property i1 -> Property i2 -> RevertableProperty p1 p2 = RevertableProperty (toIProperty p1) (toIProperty p2) class IsProp p where -- | Sets description. describe :: p -> Desc -> p toProp :: p -> Property HasInfo getDesc :: p -> Desc -- | Gets the info of the property, combined with all info -- of all children properties. getInfoRecursive :: p -> Info instance IsProp (Property HasInfo) where describe (IProperty _ a i cs) d = IProperty d a i cs toProp = id getDesc = propertyDesc getInfoRecursive (IProperty _ _ i cs) = i <> mconcat (map getInfoRecursive cs) instance IsProp (Property NoInfo) where describe (SProperty _ a cs) d = SProperty d a cs toProp = toIProperty getDesc = propertyDesc getInfoRecursive _ = mempty instance IsProp RevertableProperty where -- | Sets the description of both sides. describe (RevertableProperty p1 p2) d = RevertableProperty (describe p1 d) (describe p2 ("not " ++ d)) getDesc (RevertableProperty p1 _) = getDesc p1 toProp (RevertableProperty p1 _) = p1 -- | Return the Info of the currently active side. getInfoRecursive (RevertableProperty p1 _p2) = getInfoRecursive p1 -- | Type level calculation of the type that results from combining two types -- with `requires`. type family CombinedType x y type instance CombinedType (Property x) (Property y) = Property (CInfo x y) type instance CombinedType RevertableProperty (Property NoInfo) = RevertableProperty type instance CombinedType RevertableProperty (Property HasInfo) = RevertableProperty type instance CombinedType RevertableProperty RevertableProperty = RevertableProperty class Combines x y where -- | Indicates that the first property depends on the second, -- so before the first is ensured, the second will be ensured. requires :: x -> y -> CombinedType x y -- | Combines together two properties, resulting in one property -- that ensures the first, and if the first succeeds, ensures the second. -- The property uses the description of the first property. before :: (IsProp x, Combines y x, IsProp (CombinedType y x)) => x -> y -> CombinedType y x before x y = (y `requires` x) `describe` (getDesc x) -- | Combines together two properties, yielding a property that -- has the description and info of the first, and that has the second -- property as a child. The two actions to satisfy the properties -- are passed to a function that can combine them in arbitrary ways. combineWith :: (Combines (Property x) (Property y)) => (Propellor Result -> Propellor Result -> Propellor Result) -> Property x -> Property y -> CombinedType (Property x) (Property y) combineWith f x y = adjustPropertySatisfy (x `requires` y) $ \_ -> f (propertySatisfy $ toSProperty x) (propertySatisfy $ toSProperty y) instance Combines (Property HasInfo) (Property HasInfo) where requires (IProperty d1 a1 i1 cs1) y@(IProperty _d2 a2 _i2 _cs2) = IProperty d1 (a2 <> a1) i1 (y : cs1) instance Combines (Property HasInfo) (Property NoInfo) where requires (IProperty d1 a1 i1 cs1) y@(SProperty _d2 a2 _cs2) = IProperty d1 (a2 <> a1) i1 (toIProperty y : cs1) instance Combines (Property NoInfo) (Property HasInfo) where requires (SProperty d1 a1 cs1) y@(IProperty _d2 a2 _i2 _cs2) = IProperty d1 (a2 <> a1) mempty (y : map toIProperty cs1) instance Combines (Property NoInfo) (Property NoInfo) where requires (SProperty d1 a1 cs1) y@(SProperty _d2 a2 _cs2) = SProperty d1 (a2 <> a1) (y : cs1) instance Combines RevertableProperty (Property HasInfo) where requires (RevertableProperty p1 p2) y = RevertableProperty (p1 `requires` y) p2 instance Combines RevertableProperty (Property NoInfo) where requires (RevertableProperty p1 p2) y = RevertableProperty (p1 `requires` toIProperty y) p2 instance Combines RevertableProperty RevertableProperty where requires (RevertableProperty x1 x2) (RevertableProperty y1 y2) = RevertableProperty (x1 `requires` y1) -- when reverting, run actions in reverse order (y2 `requires` x2) -- | Information about a host. data Info = Info { _os :: Val System , _privData :: S.Set (PrivDataField, Maybe PrivDataSourceDesc, HostContext) , _sshPubKey :: M.Map SshKeyType String , _aliases :: S.Set HostName , _dns :: S.Set Dns.Record , _namedconf :: Dns.NamedConfMap , _dockerinfo :: DockerInfo Host , _chrootinfo :: ChrootInfo Host } deriving (Show) instance Monoid Info where mempty = Info mempty mempty mempty mempty mempty mempty mempty mempty mappend old new = Info { _os = _os old <> _os new , _privData = _privData old <> _privData new , _sshPubKey = _sshPubKey new `M.union` _sshPubKey old , _aliases = _aliases old <> _aliases new , _dns = _dns old <> _dns new , _namedconf = _namedconf old <> _namedconf new , _dockerinfo = _dockerinfo old <> _dockerinfo new , _chrootinfo = _chrootinfo old <> _chrootinfo new } instance Empty Info where isEmpty i = and [ isEmpty (_os i) , isEmpty (_privData i) , isEmpty (_sshPubKey i) , isEmpty (_aliases i) , isEmpty (_dns i) , isEmpty (_namedconf i) , isEmpty (_dockerinfo i) , isEmpty (_chrootinfo i) ]