Fix bug that prevented deploying ssh host keys when the file for the key didn't already exist.

This is not a new bug.

debian/changelog

@@ -1,3 +1,10 @@
+propellor (1.3.1) UNRELEASED; urgency=medium
+
+  * Fix bug that prevented deploying ssh host keys when the file for the
+    key didn't already exist.
+
+ -- Joey Hess <id@joeyh.name>  Sun, 04 Jan 2015 18:19:30 -0400
+
 propellor (1.3.0) unstable; urgency=medium
 
   * --spin checks if the DNS matches any configured IP address property

src/Propellor/Property/Ssh.hs

@@ -120,7 +120,7 @@ hostKey context keytype pub = combineProperties desc
 	desc = "ssh host key configured (" ++ fromKeyType keytype ++ ")"
 	install writer ispub key = do
 		let f = keyFile keytype ispub
-		s <- liftIO $ readFileStrict f
+		s <- liftIO $ catchDefaultIO "" $ readFileStrict f
 		if s == key
 			then noChange
 			else makeChange $ writer f key