Merge branch 'grid-as-configuration' into 'main'

Read grid configuration using the Obelisk "Config" system

Closes #59

See merge request !55

obelisk/config/common/servers.yaml

+# The Private Storage staging grid configuration.
+storage:
+  v0-roiqkiw76qcj7gcilbbut52rsxofubqugqtgnap3rgncutdueoda:
+    ann:
+      anonymous-storage-FURL: pb://oykwjvglr5h7elum5zlfll7vgiayd2ey@tcp:storage001.privatestorage-staging.com:8899/u2urs2aqarw2euuxddby7dvxkdd2rsuc
+      nickname: storage001
+      anonymous-storage-NURLs:
+        - pb://oykwjvglr5h7elum5zlfll7vgiayd2ey@tcp:storage001.privatestorage-staging.com:8899/u2urs2aqarw2euuxddby7dvxkdd2rsuc

obelisk/frontend/src/App.hs

@@ -26,7 +26,7 @@ import Reflex
     , foldDyn
     , fmapMaybe
     )
-
+import Obelisk.Configs (HasConfigs)
 import Tahoe.Announcement (Announcements)
 import MagicFolder (MagicFolder, loadGrid, loadMagicFolders, readMagicFolder)
 
@@ -50,6 +50,7 @@ initialApp
        , PerformEvent t m
        , TriggerEvent t m
        , MonadIO (Performable m)
+       , HasConfigs (Performable m)
        )
     => Event t ()     -- ^ An event to trigger loading the state.
     -> m (App t)      -- ^ The loaded application state.

obelisk/frontend/src/MagicFolder.hs

@@ -4,6 +4,7 @@
 
 module MagicFolder where
 
+import Data.Bifunctor (first)
 import Text.Megaparsec (parse)
 import qualified Data.Map.Strict as Map
 import qualified Tahoe.Directory as Directory
@@ -12,9 +13,10 @@ import Text.RawString.QQ (r)
 import qualified Data.Text as T
 import Data.Yaml (decodeEither')
 import Tahoe.Announcement (Announcements(..))
-import Control.Monad.IO.Class (MonadIO(liftIO))
+import Control.Monad.IO.Class (MonadIO)
 import Control.Exception (SomeException)
 import qualified Tahoe.MagicFoldr as MF
+import Obelisk.Configs (HasConfigs(getConfig))
 
 data MagicFolder =
   MagicFolder
@@ -29,27 +31,15 @@ newtype EntryName = EntryName { unEntryName :: T.Text } deriving (Eq, Ord, Show)
 -- | Load the announcements for the grid to use for downloads.
 --
 -- This reads "servers.yaml" from the application-private files directory.
-loadGrid :: MonadIO m => m (Either T.Text Announcements)
-loadGrid = liftIO $ do
+loadGrid :: HasConfigs m => m (Either T.Text Announcements)
+loadGrid = do
+  announcementsBytes <- getConfig "common/servers.yaml"
   case announcementsBytes of
-    Left err -> pure $ Left $ T.concat ["Could not read grid configuration: ", T.pack $ show (err :: SomeException)]
-    Right bytes ->
-      case decodeEither' bytes of
-        Left err -> pure $ Left $ T.concat ["Could not parse grid configuration: ", T.pack $ show err]
-        Right ann -> pure $ Right ann
+    Nothing -> pure . Left $ "Could not load grid configuration"
+    Just bytes ->
+      pure . first renderError $ decodeEither' bytes
       where
-    -- TODO: Figure out how we can distribute this yaml in a separate file and
-    -- still be able to get at its contents, even on Android.
-    announcementsBytes =
-        Right [r|
-          storage:
-            v0-roiqkiw76qcj7gcilbbut52rsxofubqugqtgnap3rgncutdueoda:
-              ann:
-                anonymous-storage-FURL: pb://gnuer2axzoq3ggnn7gjoybmfqsjvaow3@tcp:magnon:46185/sxytycucj5eeunlx6modfazq5byp2hpb
-                nickname: storage001
-                anonymous-storage-NURLs:
-                  - pb://4cD3anuFqhz81xiI2dtRj7eDJLsCFNXrHZZExUXotfE@magnon:46185/sxytycucj5eeunlx6modfazq5byp2hpb#v=1
-                  |]
+        renderError = T.concat . ("Could not parse grid configuration: ":) . (:[]) . T.pack . show
 
 -- | Load the configured magic-folder collective capabilities.
 --