{-# LANGUAGE PackageImports #-} {-# LANGUAGE GeneralizedNewtypeDeriving #-} {-# LANGUAGE GADTs #-} {-# LANGUAGE EmptyDataDecls #-} module Propellor.Types ( Host(..) , Property(..) , mkProperty , propertyDesc , propertySatisfy , propertyInfo , propertyChildren , RevertableProperty(..) , IsProp(..) , Desc , Info(..) , Propellor(..) , EndAction(..) , module Propellor.Types.OS , module Propellor.Types.Dns , module Propellor.Types.Result ) 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] , 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 ) -- | 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) -- | 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 = IProperty (GProperty HasInfo) | SProperty (GProperty NoInfo) -- | Constructs a Property mkProperty :: 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] -- ^ child properties -> Property mkProperty d a i cs | isEmpty i && all isEmpty (map propertyInfo cs) = SProperty (GSProperty d a cs) | otherwise = IProperty (GIProperty d a i cs) instance Show Property where show p = "property " ++ show (propertyDesc p) -- | This GADT allows creating operations that only act on Properties -- that do not add Info to their Host. data GProperty i where GIProperty :: Desc -> Propellor Result -> Info -> [Property] -> GProperty HasInfo GSProperty :: Desc -> Propellor Result -> [Property] -> GProperty NoInfo data HasInfo data NoInfo propertyDesc :: Property -> Desc propertyDesc (IProperty (GIProperty d _ _ _)) = d propertyDesc (SProperty (GSProperty d _ _)) = d propertySatisfy :: Property -> Propellor Result propertySatisfy (IProperty (GIProperty _ a _ _)) = a propertySatisfy (SProperty (GSProperty _ a _)) = a propertyInfo :: Property -> Info propertyInfo (IProperty (GIProperty _ _ i _)) = i propertyInfo (SProperty _) = mempty -- | 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 -> [Property] propertyChildren (IProperty (GIProperty _ _ _ cs)) = cs propertyChildren (SProperty (GSProperty _ _ cs)) = cs -- | A property that can be reverted. data RevertableProperty = RevertableProperty Property Property class IsProp p where -- | Sets description. describe :: p -> Desc -> p toProp :: p -> Property -- | Indicates that the first property can only be satisfied -- once the second one is. requires :: p -> Property -> p -- | Gets the info of the property, combined with all info -- of all children properties. getInfoRecursive :: p -> Info instance IsProp Property where describe (IProperty (GIProperty _ a i cs)) d = IProperty (GIProperty d a i cs) describe (SProperty (GSProperty _ a cs)) d = SProperty (GSProperty d a cs) toProp p = p getInfoRecursive (IProperty (GIProperty _ _ i cs)) = i <> mconcat (map getInfoRecursive cs) getInfoRecursive (SProperty _) = mempty x `requires` y = mkProperty (propertyDesc x) satisfy (propertyInfo x) cs where satisfy = do r <- propertySatisfy y case r of FailedChange -> return FailedChange _ -> propertySatisfy x cs = y : propertyChildren x instance IsProp RevertableProperty where -- | Sets the description of both sides. describe (RevertableProperty p1 p2) d = RevertableProperty (describe p1 d) (describe p2 ("not " ++ d)) toProp (RevertableProperty p1 _) = p1 (RevertableProperty p1 p2) `requires` y = RevertableProperty (p1 `requires` y) p2 -- | Return the Info of the currently active side. getInfoRecursive (RevertableProperty p1 _p2) = getInfoRecursive p1 type Desc = String -- | 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) ]