allow servers to have multiple or no addresses

This allows the server list to contain 3 servers although only 1 is running
so far; uploads to the others will be queued.

It also allows a server to be spread amoung multiple addresses, which may
be useful later for scaling.

This changes BackupRecord serialization, but it's not been in a keysafe
release yet, so that's not a problem.

This commit was sponsored by Boyd Stephen Smith Jr. on Patreon.

1 files changed, 21 insertions, 2 deletions

diff --git a/Types/Server.hs b/Types/Server.hs
index dd06909..e1b4191 100644
--- a/Types/Server.hs
+++ b/Types/Server.hs
@@ -3,14 +3,33 @@
  - Licensed under the GNU AGPL version 3 or higher.
  -}
 
+{-# LANGUAGE DeriveGeneric #-}
+
 module Types.Server where
 
+import Data.Aeson
+import GHC.Generics
 import Network.Wai.Handler.Warp (Port)
 
 type HostName = String
 
+-- | Server address can use either tor .onion addresses, or regular
+-- hostnames. Using tor is highly recommended, to avoid correlation
+-- attacks.
+data ServerAddress = ServerAddress HostName Port
+	deriving (Show)
+
+-- | Name used in queuing uploads to the server. Should remain stable
+-- across keysafe versions.
+newtype ServerName = ServerName String
+	deriving (Show, Generic)
+
+instance ToJSON ServerName
+instance FromJSON ServerName
+	
 data Server = Server
-	{ serverName :: HostName
-	, serverPort :: Port
+	{ serverName :: ServerName
+	, serverAddress :: [ServerAddress]
+	-- ^ A server may have multiple addresses, or no current address.
 	}
 	deriving (Show)