From 88a13d524f7c1042277ba683c54c6d0e09eb7bf4 Mon Sep 17 00:00:00 2001
From: Igor Ranieri <igor@elland.me>
Date: Mon, 12 Feb 2024 10:47:08 +0100
Subject: [PATCH 1/2] Added reason to bad gateway error for RPCs.

---
 services/brig/src/Brig/Provider/API.hs | 9 +++++----
 services/brig/src/Brig/Provider/RPC.hs | 6 +++---
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/services/brig/src/Brig/Provider/API.hs b/services/brig/src/Brig/Provider/API.hs
index d6cb9698153..0bc3963beeb 100644
--- a/services/brig/src/Brig/Provider/API.hs
+++ b/services/brig/src/Brig/Provider/API.hs
@@ -76,6 +76,7 @@ import Data.Range
 import Data.Set qualified as Set
 import Data.Text.Ascii qualified as Ascii
 import Data.Text.Encoding qualified as Text
+import Data.Text.Lazy qualified as Text
 import GHC.TypeNats
 import Imports
 import Network.HTTP.Types.Status
@@ -705,7 +706,7 @@ addBot zuid zcon cid add = do
       -- implicitly in the next line.
       pure $ FutureWork @'UnprotectedBot undefined
     wrapClientE (User.addClient (botUserId bid) bcl newClt maxPermClients (Just $ Set.singleton Public.ClientSupportsLegalholdImplicitConsent))
-      !>> const (StdError badGateway) -- MalformedPrekeys
+      !>> const (StdError $ badGatewayWith "MalformedPrekeys")
 
   -- Add the bot to the conversation
   ev <- lift $ RPC.addBotMember zuid zcon cid bid (clientId clt) pid sid
@@ -917,8 +918,8 @@ maybeInvalidUser = maybe (throwStd (errorToWai @'E.InvalidUser)) pure
 rangeChecked :: (KnownNat n, KnownNat m, Within a n m, Monad monad) => a -> (ExceptT Error monad) (Range n m a)
 rangeChecked = either (throwStd . invalidRange . fromString) pure . checkedEither
 
-badGateway :: Wai.Error
-badGateway = Wai.mkError status502 "bad-gateway" "The upstream service returned an invalid response."
+badGatewayWith :: String -> Wai.Error
+badGatewayWith str = Wai.mkError status502 "bad-gateway" ("The upstream service returned an invalid response: " <> Text.pack str)
 
 tooManyBots :: Wai.Error
 tooManyBots = Wai.mkError status409 "too-many-bots" "Maximum number of bots for the service reached."
@@ -927,7 +928,7 @@ serviceNotWhitelisted :: Wai.Error
 serviceNotWhitelisted = Wai.mkError status403 "service-not-whitelisted" "The desired service is not on the whitelist of allowed services for this team."
 
 serviceError :: RPC.ServiceError -> Wai.Error
-serviceError RPC.ServiceUnavailable = badGateway
+serviceError (RPC.ServiceUnavailableWith str) = badGatewayWith str
 serviceError RPC.ServiceBotConflict = tooManyBots
 
 randServiceToken :: MonadIO m => m Public.ServiceToken
diff --git a/services/brig/src/Brig/Provider/RPC.hs b/services/brig/src/Brig/Provider/RPC.hs
index bdb00994d4d..66f9b248035 100644
--- a/services/brig/src/Brig/Provider/RPC.hs
+++ b/services/brig/src/Brig/Provider/RPC.hs
@@ -63,7 +63,7 @@ import Wire.Rpc
 -- External RPC
 
 data ServiceError
-  = ServiceUnavailable
+  = ServiceUnavailableWith String
   | ServiceBotConflict
 
 -- | Request a new bot to be created by an external service.
@@ -86,7 +86,7 @@ createBot scon new = do
     case Bilge.statusCode rs of
       201 -> decodeBytes "External" (responseBody rs)
       409 -> throwE ServiceBotConflict
-      _ -> lift (extLogError scon rs) >> throwE ServiceUnavailable
+      _ -> lift (extLogError scon rs) >> throwE (ServiceUnavailableWith $ show rs)
   where
     -- we can't use 'responseJsonEither' instead, because we have a @Response ByteString@
     -- here, not a @Response (Maybe ByteString)@.
@@ -97,7 +97,7 @@ createBot scon new = do
       extReq scon ["bots"]
         . method POST
         . Bilge.json new
-    onExc ex = lift (extLogError scon ex) >> throwE ServiceUnavailable
+    onExc ex = lift (extLogError scon ex) >> throwE (ServiceUnavailableWith $ show ex)
 
 extReq :: ServiceConn -> [ByteString] -> Request -> Request
 extReq scon ps =

From 931b53d287d18a6fb03fe140d906e314606b0204 Mon Sep 17 00:00:00 2001
From: Igor Ranieri <igor@elland.me>
Date: Mon, 12 Feb 2024 15:01:46 +0100
Subject: [PATCH 2/2] Use displayException.

---
 services/brig/src/Brig/Provider/RPC.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/services/brig/src/Brig/Provider/RPC.hs b/services/brig/src/Brig/Provider/RPC.hs
index 66f9b248035..d11dc336a8c 100644
--- a/services/brig/src/Brig/Provider/RPC.hs
+++ b/services/brig/src/Brig/Provider/RPC.hs
@@ -97,7 +97,7 @@ createBot scon new = do
       extReq scon ["bots"]
         . method POST
         . Bilge.json new
-    onExc ex = lift (extLogError scon ex) >> throwE (ServiceUnavailableWith $ show ex)
+    onExc ex = lift (extLogError scon ex) >> throwE (ServiceUnavailableWith $ displayException ex)
 
 extReq :: ServiceConn -> [ByteString] -> Request -> Request
 extReq scon ps =