improved initial setup

Configure git to use the gpg key in --add-key, otherwise commit -S will
look for a key matching the configured email and if it doesn't find one,
will fail.

Propellor/CmdLine.hs

@@ -290,9 +290,11 @@ boot attr ps = do
 	mainProperties attr ps
 
 addKey :: String -> IO ()
-addKey keyid = exitBool =<< allM id [ gpg, gitadd, gitcommit ]
+addKey keyid = exitBool =<< allM id [ gpg, gitadd, gitconfig, gitcommit ]
   where
-	gpg = boolSystem "sh"
+	gpg = do
+		createDirectoryIfMissing True privDataDir
+		boolSystem "sh"
 			[ Param "-c"
 			, Param $ "gpg --export " ++ keyid ++ " | gpg " ++
 				unwords (gpgopts ++ ["--import"])
@@ -301,6 +303,13 @@ addKey keyid = exitBool =<< allM id [ gpg, gitadd, gitcommit ]
 		[ Param "add"
 		, File keyring
 		]
+
+	gitconfig = boolSystem "git"
+		[ Param "config"
+		, Param "user.signingkey"
+		, Param keyid
+		]
+
 	gitcommit = gitCommit
 		[ File keyring
 		, Param "-m"

doc/README.mdwn

@@ -6,7 +6,8 @@ are satisfied.
 Propellor is configured via a git repository, which typically lives
 in `~/.propellor/` on your development machine. Propellor clones the
 repository to each host it manages, in a 
-[secure](http://propellor.branchable.com/security/) way.
+[secure](http://propellor.branchable.com/security/) way. The git repository
+contains the full source code to Propellor, along with its config file.
 
 Properties are defined using Haskell. Edit `~/.propellor/config.hs`
 to get started. There is fairly complete 
@@ -40,11 +41,12 @@ see [configuration for the Haskell newbie](https://propellor.branchable.com/hask
      `apt-get install propellor`
 2. Run propellor for the first time. It will set up a `~/.propellor/` git
    repository for you.
-3. `cd ~/.propellor/`; use git to push the repository to a central
+3. If you don't have a gpg private key already, generate one: `gpg --gen-key`
+4. Run: `propellor --add-key $KEYID`, which will make propellor trust
+   your gpg key, and will sign your `~/.propellor` repository using it.
+5. `cd ~/.propellor/`; use git to push the repository to a central
    server (github, or your own git server). Configure that central
    server as the origin remote of the repository.
-4. If you don't have a gpg private key, generate one: `gpg --gen-key`
-5. Run: `propellor --add-key $KEYID`
 6. Edit `~/.propellor/config.hs`, and add a host you want to manage.
    You can start by not adding any properties, or only a few.
 7. Pick a host and run: `propellor --spin $HOST`