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authorJoey Hess2016-03-28 05:53:38 -0400
committerJoey Hess2016-03-28 05:55:48 -0400
commita1655d24bbb1db9caccdf93eae8110d746389ae2 (patch)
tree66b6890d852c19daec2306920fecf9108e055273 /src/Propellor/Engine.hs
parentebf30061d8f8a251330070e69c2710fe4a8fd9da (diff)
type safe targets for properties
* Property types have been improved to indicate what systems they target. This prevents using eg, Property FreeBSD on a Debian system. Transition guide for this sweeping API change: - Change "host name & foo & bar" to "host name $ props & foo & bar" - Similarly, `propertyList` and `combineProperties` need `props` to be used to combine together properties; they no longer accept lists of properties. (If you have such a list, use `toProps`.) - And similarly, Chroot, Docker, and Systemd container need `props` to be used to combine together the properies used inside them. - The `os` property is removed. Instead use `osDebian`, `osBuntish`, or `osFreeBSD`. These tell the type checker the target OS of a host. - Change "Property NoInfo" to "Property UnixLike" - Change "Property HasInfo" to "Property (HasInfo + UnixLike)" - Change "RevertableProperty NoInfo" to "RevertableProperty UnixLike UnixLike" - Change "RevertableProperty HasInfo" to "RevertableProperty (HasInfo + UnixLike) UnixLike" - GHC needs {-# LANGUAGE TypeOperators #-} to use these fancy types. This is enabled by default for all modules in propellor.cabal. But if you are using propellor as a library, you may need to enable it manually. - If you know a property only works on a particular OS, like Debian or FreeBSD, use that instead of "UnixLike". For example: "Property Debian" - It's also possible make a property support a set of OS's, for example: "Property (Debian + FreeBSD)" - Removed `infoProperty` and `simpleProperty` constructors, instead use `property` to construct a Property. - Due to the polymorphic type returned by `property`, additional type signatures tend to be needed when using it. For example, this will fail to type check, because the type checker cannot guess what type you intend the intermediate property "go" to have: foo :: Property UnixLike foo = go `requires` bar where go = property "foo" (return NoChange) To fix, specify the type of go: go :: Property UnixLike - `ensureProperty` now needs to be passed a witness to the type of the property it's used in. change this: foo = property desc $ ... ensureProperty bar to this: foo = property' desc $ \w -> ... ensureProperty w bar - General purpose properties like cmdProperty have type "Property UnixLike". When using that to run a command only available on Debian, you can tighten the type to only the OS that your more specific property works on. For example: upgraded :: Property Debian upgraded = tightenTargets (cmdProperty "apt-get" ["upgrade"]) - Several utility functions have been renamed: getInfo to fromInfo propertyInfo to getInfo propertyDesc to getDesc propertyChildren to getChildren * The new `pickOS` property combinator can be used to combine different properties, supporting different OS's, into one Property that chooses which to use based on the Host's OS. * Re-enabled -O0 in propellor.cabal to reign in ghc's memory use handling these complex new types. * Added dependency on concurrent-output; removed embedded copy.
Diffstat (limited to 'src/Propellor/Engine.hs')
-rw-r--r--src/Propellor/Engine.hs23
1 files changed, 12 insertions, 11 deletions
diff --git a/src/Propellor/Engine.hs b/src/Propellor/Engine.hs
index 2e914d67..f0035c40 100644
--- a/src/Propellor/Engine.hs
+++ b/src/Propellor/Engine.hs
@@ -1,11 +1,10 @@
{-# LANGUAGE PackageImports #-}
-{-# LANGUAGE GADTs #-}
+{-# LANGUAGE DataKinds #-}
module Propellor.Engine (
mainProperties,
runPropellor,
- ensureProperty,
- ensureProperties,
+ ensureChildProperties,
fromHost,
fromHost',
onlyProcess,
@@ -23,24 +22,26 @@ import Control.Applicative
import Prelude
import Propellor.Types
+import Propellor.Types.MetaTypes
+import Propellor.Types.Core
import Propellor.Message
import Propellor.Exception
import Propellor.Info
-import Propellor.Property
import Utility.Exception
-- | Gets the Properties of a Host, and ensures them all,
-- with nice display of what's being done.
mainProperties :: Host -> IO ()
mainProperties host = do
- ret <- runPropellor host $
- ensureProperties [ignoreInfo $ infoProperty "overall" (ensureProperties ps) mempty mempty]
+ ret <- runPropellor host $ ensureChildProperties [toChildProperty overall]
messagesDone
case ret of
FailedChange -> exitWith (ExitFailure 1)
_ -> exitWith ExitSuccess
where
- ps = map ignoreInfo $ hostProperties host
+ overall :: Property (MetaTypes '[])
+ overall = property "overall" $
+ ensureChildProperties (hostProperties host)
-- | Runs a Propellor action with the specified host.
--
@@ -58,14 +59,14 @@ runEndAction host res (EndAction desc a) = actionMessageOn (hostName host) desc
(ret, _s, _) <- runRWST (runWithHost (catchPropellor (a res))) host ()
return ret
--- | Ensures a list of Properties, with a display of each as it runs.
-ensureProperties :: [Property NoInfo] -> Propellor Result
-ensureProperties ps = ensure ps NoChange
+-- | Ensures the child properties, with a display of each as it runs.
+ensureChildProperties :: [ChildProperty] -> Propellor Result
+ensureChildProperties ps = ensure ps NoChange
where
ensure [] rs = return rs
ensure (p:ls) rs = do
hn <- asks hostName
- r <- actionMessageOn hn (propertyDesc p) (ensureProperty p)
+ r <- actionMessageOn hn (getDesc p) (catchPropellor $ getSatisfy p)
ensure ls (r <> rs)
-- | Lifts an action into the context of a different host.