Git over HTTP: Add initial always-denying ref discovery handler

config/routes

@@ -50,6 +50,8 @@
 /u/#Text/r/#Text/s/#Text/+Texts         RepoSourceR     GET
 /u/#Text/r/#Text/c                      RepoCommitsR    GET
 
+/u/#Text/r/#Text/git/info/refs          GitRefDiscoverR GET
+
 -- /u/#Text/p/#Text/t           TicketsR   GET
 -- /u/#Text/p/#Text/t/#TicketId TicketR    GET
 -- /u/#Text/p/#Text/w           WikiR      GET

src/Vervis/Application.hs

@@ -52,6 +52,7 @@ import Yesod.Default.Main                   (LogFunc)
 -- Import all relevant handler modules here.
 -- Don't forget to add new modules to your cabal file!
 import Vervis.Handler.Common
+import Vervis.Handler.Git
 import Vervis.Handler.Home
 import Vervis.Handler.Key
 import Vervis.Handler.Person

src/Vervis/Handler/Git.hs

@@ -0,0 +1,42 @@
+{- This file is part of Vervis.
+ -
+ - Written in 2016 by fr33domlover <fr33domlover@riseup.net>.
+ -
+ - ♡ Copying is an act of love. Please copy, reuse and share.
+ -
+ - The author(s) have dedicated all copyright and related and neighboring
+ - rights to this software to the public domain worldwide. This software is
+ - distributed without any warranty.
+ -
+ - You should have received a copy of the CC0 Public Domain Dedication along
+ - with this software. If not, see
+ - <http://creativecommons.org/publicdomain/zero/1.0/>.
+ -}
+
+module Vervis.Handler.Git
+    ( getGitRefDiscoverR
+    )
+where
+
+import Prelude
+
+import Control.Monad.IO.Class (liftIO)
+import Data.Git.Storage (isRepo)
+import Data.String (fromString)
+import Data.Text (Text)
+import Yesod.Core.Handler
+
+import Vervis.Foundation (Handler)
+import Vervis.Path (askRepoDir)
+
+getGitRefDiscoverR :: Text -> Text -> Handler Text
+getGitRefDiscoverR sharer repo = do
+    path <- askRepoDir sharer repo
+    seemsThere <- liftIO $ isRepo $ fromString path
+    if seemsThere
+        then do
+            rq <- getRequest
+            case reqGetParams rq of
+                [("service", _)] -> permissionDenied "Service not supported"
+                _                -> notFound
+        else notFound

vervis.cabal

@@ -60,6 +60,7 @@ library
                        Vervis.Settings
                        Vervis.Settings.StaticFiles
                        Vervis.Handler.Common
+                       Vervis.Handler.Git
                        Vervis.Handler.Home
                        Vervis.Handler.Key
                        Vervis.Handler.Person