Stack support.

* Stack support. "git config propellor.buildsystem stack" will make
  propellor build its config using stack.
* When propellor is installed using stack, propellor --init will
  automatically set propellor.buildsystem=stack.

2 files changed, 84 insertions, 17 deletions

diff --git a/src/Propellor/Bootstrap.hs b/src/Propellor/Bootstrap.hs
index 969e1a42..300be156 100644
--- a/src/Propellor/Bootstrap.hs
+++ b/src/Propellor/Bootstrap.hs
@@ -7,6 +7,7 @@ module Propellor.Bootstrap (
 
 import Propellor.Base
 import Propellor.Types.Info
+import Propellor.Git.Config
 
 import System.Posix.Files
 import Data.List
@@ -139,16 +140,22 @@ buildPropellor mh = unlessM (actionMessage "Propellor build" (build msys)) $
 		Just (InfoVal sys) -> Just sys
 		_ -> Nothing
 
--- Build propellor using cabal, and symlink propellor to where cabal
--- leaves the built binary.
---
+-- Build propellor using cabal or stack, and symlink propellor to the
+-- built binary.
+build :: Maybe System -> IO Bool
+build msys = catchBoolIO $ do
+	bs <- getGitConfigValue "propellor.buildsystem"
+	case bs of
+		Just "stack" -> stackBuild msys
+		_ -> cabalBuild msys
+
 -- For speed, only runs cabal configure when it's not been run before.
 -- If the build fails cabal may need to have configure re-run.
 --
 -- If the cabal configure fails, and a System is provided, installs
 -- dependencies and retries.
-build :: Maybe System -> IO Bool
-build msys = catchBoolIO $ do
+cabalBuild :: Maybe System -> IO Bool
+cabalBuild msys = do
 	make "dist/setup-config" ["propellor.cabal"] cabal_configure
 	unlessM cabal_build $
 		unlessM (cabal_configure <&&> cabal_build) $
@@ -163,14 +170,11 @@ build msys = catchBoolIO $ do
 	unlessM (boolSystem "cp" [Param "-af", Param cabalbuiltbin, Param (tmpfor safetycopy)]) $
 		error "cp of binary failed"
 	rename (tmpfor safetycopy) safetycopy
-	createSymbolicLink safetycopy (tmpfor dest)
-	rename (tmpfor dest) dest
+	symlinkPropellorBin safetycopy
 	return True
   where
-	dest = "propellor"
 	cabalbuiltbin = "dist/build/propellor-config/propellor-config"
 	safetycopy = cabalbuiltbin ++ ".built"
-	tmpfor f = f ++ ".propellortmp"
 	cabal_configure = ifM (cabal ["configure"])
 		( return True
 		, case msys of
@@ -181,6 +185,35 @@ build msys = catchBoolIO $ do
 		)
 	cabal_build = cabal ["build", "propellor-config"]
 
+stackBuild :: Maybe System -> IO Bool
+stackBuild _msys = do
+	createDirectoryIfMissing True builddest
+	ifM (stack buildparams)
+		( do
+			symlinkPropellorBin (builddest </> "propellor-config")
+			return True
+		, return False
+		)
+  where
+ 	builddest = ".built"
+	buildparams =
+		[ "--local-bin-path", builddest
+		, "build"
+		, ":propellor-config" -- only build config program
+		, "--copy-bins"
+		]
+
+-- Atomic symlink creation/update.
+symlinkPropellorBin :: FilePath -> IO ()
+symlinkPropellorBin bin = do
+	createSymbolicLink bin (tmpfor dest)
+	rename (tmpfor dest) dest
+  where
+	dest = "propellor"
+
+tmpfor :: FilePath -> FilePath
+tmpfor f = f ++ ".propellortmp"
+
 make :: FilePath -> [FilePath] -> IO Bool -> IO ()
 make dest srcs builder = do
 	dt <- getmtime dest
@@ -193,3 +226,6 @@ make dest srcs builder = do
 
 cabal :: [String] -> IO Bool
 cabal = boolSystem "cabal" . map Param
+
+stack :: [String] -> IO Bool
+stack = boolSystem "stack" . map Param
diff --git a/src/Propellor/DotDir.hs b/src/Propellor/DotDir.hs
index f0dace2f..90147abe 100644
--- a/src/Propellor/DotDir.hs
+++ b/src/Propellor/DotDir.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE CPP #-}
+
 module Propellor.DotDir where
 
 import Propellor.Message
@@ -11,9 +13,12 @@ import Utility.Process
 import Utility.SafeCommand
 import Utility.Exception
 import Utility.Path
+-- This module is autogenerated by the build system.
+import qualified Paths_propellor as Package
 
 import Data.Char
 import Data.List
+import Data.Version
 import Control.Monad
 import Control.Monad.IfElse
 import System.Directory
@@ -48,6 +53,15 @@ dotPropellor = do
 	home <- myHomeDir
 	return (home </> ".propellor")
 
+data InitCfg = UseCabal | UseStack
+
+initCfg :: InitCfg
+#ifdef USE_STACK
+initCfg = UseStack
+#else
+initCfg = UseCabal
+#endif
+
 interactiveInit :: IO ()
 interactiveInit = ifM (doesDirectoryExist =<< dotPropellor)
 	( error "~/.propellor/ already exists, not doing anything"
@@ -95,7 +109,7 @@ section = do
 	putStrLn ""
 
 setup :: IO ()
-setup = do
+setup initcfg = do
 	putStrLn "Propellor's configuration file is ~/.propellor/config.hs"
 	putStrLn ""
 	putStrLn "Lets get you started with a simple config that you can adapt"
@@ -103,14 +117,21 @@ setup = do
 	putStrLn "   A: A clone of propellor's git repository    (most flexible)"
 	putStrLn "   B: The bare minimum files to use propellor  (most simple)"
 	prompt "Which would you prefer?"
-		[ ("A", actionMessage "Cloning propellor's git repository" fullClone >> return ())
-		, ("B", actionMessage "Creating minimal config" minimalConfig >> return ())
+		[ ("A", void $ actionMessage "Cloning propellor's git repository" fullClone)
+		, ("B", void $ actionMessage "Creating minimal config" minimalConfig)
 		]
 	changeWorkingDirectory =<< dotPropellor
 
 	section
 	putStrLn "Let's try building the propellor configuration, to make sure it will work..."
 	putStrLn ""
+	void $ boolSystem "git"
+		[ Param "config"
+		, Param "propellor.buildsystem"
+		, Param $ case initCfg of
+			UseCabal -> "cabal"
+			UseStack -> "stack"
+		]
 	buildPropellor Nothing
 	putStrLn ""
 	putStrLn "Great! Propellor is bootstrapped."
@@ -197,15 +218,16 @@ minimalConfig :: IO Result
 minimalConfig = do
 	d <- dotPropellor
 	createDirectoryIfMissing True d
-	let cabalfile = d </> "config.cabal"
-	let configfile = d </> "config.hs"
-	writeFile cabalfile (unlines cabalcontent)
-	writeFile configfile (unlines configcontent)
 	changeWorkingDirectory d
 	void $ boolSystem "git" [Param "init"]
-	void $ boolSystem "git" [Param "add" , File cabalfile, File configfile]
+	addfile "config.cabal" cabalcontent
+	addfile "config.hs" configcontent
+	addfile "stack.yaml" stackcontent
 	return MadeChange
   where
+	addfile f content = do
+		writeFile f (unlines content)
+		void $ boolSystem "git" [Param "add" , File f]
 	cabalcontent =
 		[ "-- This is a cabal file to use to build your propellor configuration."
 		, ""
@@ -252,6 +274,15 @@ minimalConfig = do
 		, "        & Cron.runPropellor (Cron.Times \"30 * * * *\")"
 		, ""
 		]
+	stackcontent =
+		-- This should be the same resolver version in propellor's
+		-- own stack.yaml
+		[ "resolver: lts-5.10"
+		, "packages:"
+		, "- '.'"
+		, "extra-deps:"
+		, "- propellor-" ++ showVersion Package.version
+		]
 
 fullClone :: IO Result
 fullClone = do