feat: add db-pool-automatic-recovery configuration to disable connection retrying

src/PostgREST/AppState.hs

@@ -281,8 +281,9 @@ internalConnectionWorker appState = work
           -- Fatal error when connecting
           logWithZTime appState reason >> killThread (getMainThreadId appState)
         NotConnected ->
-          -- Unreachable because establishConnection will keep trying to connect
-          return ()
+          -- Unreachable because establishConnection will keep trying to connect, unless disable-recovery is turned on
+          unless configDbPoolAutomaticRecovery
+              $ logWithZTime appState "Automatic recovery disabled, exiting." >> killThread (getMainThreadId appState)
         Connected actualPgVersion -> do
           -- Procede with initialization
           putPgVersion appState actualPgVersion
@@ -344,9 +345,10 @@ establishConnection appState =
 
     shouldRetry :: RetryStatus -> ConnectionStatus -> IO Bool
     shouldRetry rs isConnSucc = do
+      AppConfig{..} <- getConfig appState
       let
         delay = fromMaybe 0 (rsPreviousDelay rs) `div` backoffMicroseconds
-        itShould = NotConnected == isConnSucc
+        itShould = NotConnected == isConnSucc && configDbPoolAutomaticRecovery
       when itShould . logWithZTime appState $
         "Attempting to reconnect to the database in "
         <> (show delay::Text)
@@ -420,7 +422,7 @@ listener appState = do
   waitListener appState
 
   -- forkFinally allows to detect if the thread dies
-  void . flip forkFinally (handleFinally dbChannel) $ do
+  void . flip forkFinally (handleFinally dbChannel configDbPoolAutomaticRecovery) $ do
     dbOrError <- acquire $ toUtf8 (addFallbackAppName prettyVersion configDbUri)
     case dbOrError of
       Right db -> do
@@ -431,7 +433,9 @@ listener appState = do
       _ ->
         die $ "Could not listen for notifications on the " <> dbChannel <> " channel"
   where
-    handleFinally dbChannel _ = do
+    handleFinally _ False _ =
+      logWithZTime appState "Automatic recovery disabled, exiting." >> killThread (getMainThreadId appState)
+    handleFinally dbChannel True _ = do
       -- if the thread dies, we try to recover
       logWithZTime appState $ "Retrying listening for notifications on the " <> dbChannel <> " channel.."
       putIsListenerOn appState False

src/PostgREST/CLI.hs

@@ -162,6 +162,9 @@ exampleConfigFile =
       |## Time in seconds after which to recycle unused pool connections
       |# db-pool-max-idletime = 30
       |
+      |## Allow autmatic database connection retrying
+      |# db-pool-automatic-recovery = true
+      |
       |## Stored proc to exec immediately after auth
       |# db-pre-request = "stored_proc_name"
       |

src/PostgREST/Config.hs

@@ -80,6 +80,7 @@ data AppConfig = AppConfig
   , configDbPoolAcquisitionTimeout :: Int
   , configDbPoolMaxLifetime        :: Int
   , configDbPoolMaxIdletime        :: Int
+  , configDbPoolAutomaticRecovery  :: Bool
   , configDbPreRequest             :: Maybe QualifiedIdentifier
   , configDbPreparedStatements     :: Bool
   , configDbRootSpec               :: Maybe QualifiedIdentifier
@@ -147,6 +148,7 @@ toText conf =
       ,("db-pool-acquisition-timeout",   show . configDbPoolAcquisitionTimeout)
       ,("db-pool-max-lifetime",          show . configDbPoolMaxLifetime)
       ,("db-pool-max-idletime",          show . configDbPoolMaxIdletime)
+      ,("db-pool-automatic-recovery",    T.toLower . show . configDbPoolAutomaticRecovery)
       ,("db-pre-request",            q . maybe mempty dumpQi . configDbPreRequest)
       ,("db-prepared-statements",        T.toLower . show . configDbPreparedStatements)
       ,("db-root-spec",              q . maybe mempty dumpQi . configDbRootSpec)
@@ -241,6 +243,7 @@ parser optPath env dbSettings roleSettings roleIsolationLvl =
     <*> (fromMaybe 1800 <$> optInt "db-pool-max-lifetime")
     <*> (fromMaybe 30 <$> optWithAlias (optInt "db-pool-timeout")
                                        (optInt "db-pool-max-idletime"))
+    <*> (fromMaybe True <$> optBool "db-pool-automatic-recovery")
     <*> (fmap toQi <$> optWithAlias (optString "db-pre-request")
                                     (optString "pre-request"))
     <*> (fromMaybe True <$> optBool "db-prepared-statements")