Added --unset to delete a privdata field.

debian/changelog

@@ -3,6 +3,7 @@ propellor (2.6.0) UNRELEASED; urgency=medium
   * Replace String type synonym Docker.Image by a data type
     which allows to specify an image name and an optional tag. (API change)
     Thanks, Antoine Eiche.
+  * Added --unset to delete a privdata field.
 
  -- Joey Hess <id@joeyh.name>  Tue, 16 Jun 2015 14:49:12 -0400
 

doc/usage.mdwn

@@ -71,6 +71,10 @@ and configured in haskell.
 
   Sets a field of privdata. The content is read in from stdin.
 
+* propellor --unset field context
+
+  Removes a value from the privdata store.
+
 * propellor --dump field context
 
   Outputs the privdata value to stdout.

src/Propellor/CmdLine.hs

@@ -51,6 +51,7 @@ processCmdLine = go =<< getArgs
 		_ -> Spin <$> mapM hostname ps <*> pure Nothing
 	go ("--add-key":k:[]) = return $ AddKey k
 	go ("--set":f:c:[]) = withprivfield f c Set
+	go ("--unset":f:c:[]) = withprivfield f c Unset
 	go ("--dump":f:c:[]) = withprivfield f c Dump
 	go ("--edit":f:c:[]) = withprivfield f c Edit
 	go ("--list-fields":[]) = return ListFields
@@ -94,6 +95,7 @@ defaultMain hostlist = do
 	go _ (Continue cmdline) = go False cmdline
 	go _ Check = return ()
 	go _ (Set field context) = setPrivData field context
+	go _ (Unset field context) = unsetPrivData field context
 	go _ (Dump field context) = dumpPrivData field context
 	go _ (Edit field context) = editPrivData field context
 	go _ ListFields = listPrivDataFields hostlist

src/Propellor/PrivData.hs

@@ -6,6 +6,7 @@ module Propellor.PrivData (
 	withSomePrivData,
 	addPrivData,
 	setPrivData,
+	unsetPrivData,
 	dumpPrivData,
 	editPrivData,
 	filterPrivData,
@@ -143,6 +144,11 @@ setPrivData field context = do
 	putStrLn "Enter private data on stdin; ctrl-D when done:"
 	setPrivDataTo field context =<< hGetContentsStrict stdin
 
+unsetPrivData :: PrivDataField -> Context -> IO ()
+unsetPrivData field context = do
+	modifyPrivData $ M.delete (field, context)
+	putStrLn "Private data unset."
+
 dumpPrivData :: PrivDataField -> Context -> IO ()
 dumpPrivData field context =
 	maybe (error "Requested privdata is not set.") putStrLn
@@ -192,17 +198,22 @@ listPrivDataFields hosts = do
 
 setPrivDataTo :: PrivDataField -> Context -> PrivData -> IO ()
 setPrivDataTo field context value = do
-	makePrivDataDir
+	modifyPrivData set
-	m <- decryptPrivData
-	let m' = M.insert (field, context) (chomp value) m
-	gpgEncrypt privDataFile (show m')
 	putStrLn "Private data set."
-	void $ boolSystem "git" [Param "add", File privDataFile]
   where
+	set = M.insert (field, context) (chomp value)
 	chomp s
 		| end s == "\n" = chomp (beginning s)
 		| otherwise = s
 
+modifyPrivData :: (PrivMap -> PrivMap) -> IO ()
+modifyPrivData f = do
+	makePrivDataDir
+	m <- decryptPrivData
+	let m' = f m
+	gpgEncrypt privDataFile (show m')
+	void $ boolSystem "git" [Param "add", File privDataFile]
+
 decryptPrivData :: IO PrivMap
 decryptPrivData = fromMaybe M.empty . readish <$> gpgDecrypt privDataFile
 

src/Propellor/Types/CmdLine.hs

@@ -10,6 +10,7 @@ data CmdLine
 	| Spin [HostName] (Maybe HostName)
 	| SimpleRun HostName
 	| Set PrivDataField Context
+	| Unset PrivDataField Context
 	| Dump PrivDataField Context
 	| Edit PrivDataField Context
 	| ListFields