catch and handle bootstrap join errors

src/Hash2Pub/FediChord.hs

@@ -138,6 +138,7 @@ fediChordBootstrapJoin ns (joinHost, joinPort) =
                            initCache bootstrapResponse
                fediChordJoin bootstrapCache ns
                                                    )
+       `catch` (\e -> pure . Left $ "Error at bootstrap joining: " <> displayException (e :: IOException))
 
 -- | join a node to the DHT, using the provided cache snapshot for resolving the new
 -- node's position.

src/Hash2Pub/Main.hs

@@ -4,6 +4,7 @@ import           Control.Concurrent
 import           Control.Exception
 import           Data.IP            (IPv6, toHostAddress6)
 import           System.Environment
+import           Data.Either
 
 import           Hash2Pub.FediChord
 
@@ -23,10 +24,21 @@ main = do
         tryJoining (bn:bns) = do
             j <- fediChordBootstrapJoin thisNode bn
             case j of
-              Left _ -> tryJoining bns
+              Left err -> putStrLn ("join error: " <> err) >> tryJoining bns
               Right joined -> pure $ Right joined
         tryJoining [] = pure $ Left "Exhausted all bootstrap points for joining."
     joinedState <- tryJoining $ confBootstrapNodes conf
+    either (\err ->
+        -- handle unsuccessful join
+
+        putStrLn $ err <> " Error joining, start listening for incoming requests anyways"
+        -- TODO: periodic retry
+           )
+           (\joinedNS ->
+        -- launch main eventloop with successfully joined state
+        putStrLn ("successful join at " <> (show . getNid $ joinedNS))
+           )
+        joinedState
     -- stop main thread from terminating during development
     getChar
     pure ()