From 3eb028f8e5460e5e88beaf6b1deb992a2b2ffdd2 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Wed, 1 Nov 2023 14:27:37 +0100
Subject: [PATCH 01/28] app: quick'n'dirty displaying of bound port

---
 src/PostgREST/App.hs | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/PostgREST/App.hs b/src/PostgREST/App.hs
index b4a75b777d..7cef4d17c2 100644
--- a/src/PostgREST/App.hs
+++ b/src/PostgREST/App.hs
@@ -29,6 +29,7 @@ import System.Posix.Types       (FileMode)
 
 import qualified Data.HashMap.Strict        as HM
 import qualified Data.Text.Encoding         as T
+import qualified Data.Text                 as T (unpack)
 import qualified Hasql.Transaction.Sessions as SQL
 import qualified Network.Wai                as Wai
 import qualified Network.Wai.Handler.Warp   as Warp
@@ -66,6 +67,8 @@ import qualified Data.Map              as Map (fromList)
 import qualified Network.HTTP.Types    as HTTP
 import           Protolude             hiding (Handler)
 import           System.TimeIt         (timeItT)
+import qualified Network.Socket as Socket
+import qualified Control.Exception as E
 
 type Handler = ExceptT Error
 
@@ -96,8 +99,22 @@ run installHandlers maybeRunWithSocket appState = do
           panic "Cannot run with unix socket on non-unix platforms."
     Nothing ->
       do
-        AppState.logWithZTime appState $ "Listening on port " <> show configServerPort
-        Warp.runSettings (serverSettings conf) app
+        maddr <- resolveAddress configServerHost configServerPort
+        case maddr of
+          Nothing -> panic ("Could not resolve address " <> show configServerHost <> " port " <> show configServerPort)
+          Just addr -> do
+            sock <- E.bracketOnError (Socket.openSocket addr) Socket.close $ \sock -> do 
+              Socket.bind sock $ Socket.addrAddress addr
+              pure sock
+            port <- Socket.socketPort sock
+            AppState.logWithZTime appState $ "Listening on port " <> show port
+            Warp.runSettingsSocket (serverSettings conf) sock app 
+  
+  where
+    resolveAddress host port = do
+      let hints = Socket.defaultHints { Socket.addrSocketType = Socket.Stream }
+      head <$> Socket.getAddrInfo (Just hints) (Just $ T.unpack host) (Just $ show port)
+      
 
 serverSettings :: AppConfig -> Warp.Settings
 serverSettings AppConfig{..} =

From eff8e1a7a988d3ba0886e14b622bb45dde5a3d4d Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Wed, 1 Nov 2023 15:30:03 +0100
Subject: [PATCH 02/28] postgrest style

---
 src/PostgREST/App.hs | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/PostgREST/App.hs b/src/PostgREST/App.hs
index 7cef4d17c2..84e77c63a1 100644
--- a/src/PostgREST/App.hs
+++ b/src/PostgREST/App.hs
@@ -28,8 +28,8 @@ import Network.Wai.Handler.Warp (defaultSettings, setHost, setPort,
 import System.Posix.Types       (FileMode)
 
 import qualified Data.HashMap.Strict        as HM
+import qualified Data.Text                  as T (unpack)
 import qualified Data.Text.Encoding         as T
-import qualified Data.Text                 as T (unpack)
 import qualified Hasql.Transaction.Sessions as SQL
 import qualified Network.Wai                as Wai
 import qualified Network.Wai.Handler.Warp   as Warp
@@ -61,14 +61,14 @@ import PostgREST.SchemaCache          (SchemaCache (..))
 import PostgREST.SchemaCache.Routine  (Routine (..))
 import PostgREST.Version              (docsVersion, prettyVersion)
 
+import qualified Control.Exception     as E
 import qualified Data.ByteString.Char8 as BS
 import qualified Data.List             as L
 import qualified Data.Map              as Map (fromList)
 import qualified Network.HTTP.Types    as HTTP
+import qualified Network.Socket        as Socket
 import           Protolude             hiding (Handler)
 import           System.TimeIt         (timeItT)
-import qualified Network.Socket as Socket
-import qualified Control.Exception as E
 
 type Handler = ExceptT Error
 
@@ -103,18 +103,18 @@ run installHandlers maybeRunWithSocket appState = do
         case maddr of
           Nothing -> panic ("Could not resolve address " <> show configServerHost <> " port " <> show configServerPort)
           Just addr -> do
-            sock <- E.bracketOnError (Socket.openSocket addr) Socket.close $ \sock -> do 
+            sock <- E.bracketOnError (Socket.openSocket addr) Socket.close $ \sock -> do
               Socket.bind sock $ Socket.addrAddress addr
               pure sock
             port <- Socket.socketPort sock
             AppState.logWithZTime appState $ "Listening on port " <> show port
-            Warp.runSettingsSocket (serverSettings conf) sock app 
-  
+            Warp.runSettingsSocket (serverSettings conf) sock app
+
   where
     resolveAddress host port = do
       let hints = Socket.defaultHints { Socket.addrSocketType = Socket.Stream }
       head <$> Socket.getAddrInfo (Just hints) (Just $ T.unpack host) (Just $ show port)
-      
+
 
 serverSettings :: AppConfig -> Warp.Settings
 serverSettings AppConfig{..} =

From f7c569702b7dacc63df75699c2a3c9f5e4f892c7 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Fri, 3 Nov 2023 17:20:38 +0100
Subject: [PATCH 03/28] create app sockets ourselves

also store them in AppState
simplify Admin.reachMainApp
---
 src/PostgREST/Admin.hs    | 42 +++++---------------------
 src/PostgREST/App.hs      | 34 +++++----------------
 src/PostgREST/AppState.hs | 62 ++++++++++++++++++++++++++++++++++++---
 3 files changed, 74 insertions(+), 64 deletions(-)

diff --git a/src/PostgREST/Admin.hs b/src/PostgREST/Admin.hs
index ffc61cbfba..0cf447f60a 100644
--- a/src/PostgREST/Admin.hs
+++ b/src/PostgREST/Admin.hs
@@ -22,19 +22,20 @@ import PostgREST.Config   (AppConfig (..))
 import qualified PostgREST.AppState as AppState
 
 import Protolude
+import Protolude.Partial (fromJust)
 
 runAdmin :: AppConfig -> AppState -> Warp.Settings -> IO ()
 runAdmin conf@AppConfig{configAdminServerPort} appState settings =
-  whenJust configAdminServerPort $ \adminPort -> do
-    AppState.logWithZTime appState $ "Admin server listening on port " <> show adminPort
-    void . forkIO $ Warp.runSettings (settings & Warp.setPort adminPort) adminApp
+  whenJust (AppState.getSocketAdmin appState) $ \adminSocket -> do
+    AppState.logWithZTime appState $ "Admin server listening on port " <> show (fromIntegral $ fromJust configAdminServerPort)
+    void . forkIO $ Warp.runSettingsSocket settings adminSocket adminApp
   where
     adminApp = admin appState conf
 
 -- | PostgREST admin application
 admin :: AppState.AppState -> AppConfig -> Wai.Application
 admin appState appConfig req respond  = do
-  isMainAppReachable  <- any isRight <$> reachMainApp appConfig
+  isMainAppReachable  <- isRight <$> reachMainApp appConfig (AppState.getSocketREST appState)
   isSchemaCacheLoaded <- isJust <$> AppState.getSchemaCache appState
   isConnectionUp      <-
     if configDbChannelEnabled appConfig
@@ -53,35 +54,8 @@ admin appState appConfig req respond  = do
 -- Note that it doesn't even send a valid HTTP request, we just want to check that the main app is accepting connections
 -- The code for resolving the "*4", "!4", "*6", "!6", "*" special values is taken from
 -- https://hackage.haskell.org/package/streaming-commons-0.2.2.4/docs/src/Data.Streaming.Network.html#bindPortGenEx
-reachMainApp :: AppConfig -> IO [Either IOException ()]
-reachMainApp AppConfig{..} =
-  case configServerUnixSocket of
-    Just path ->  do
-      sock <- socket AF_UNIX Stream 0
-      (:[]) <$> try (do
-        connect sock $ SockAddrUnix path
-        withSocketsDo $ bracket (pure sock) close sendEmpty)
-    Nothing -> do
-      let
-        host | configServerHost `elem` ["*4", "!4", "*6", "!6", "*"] = Nothing
-             | otherwise                                             = Just configServerHost
-        filterAddrs xs =
-          case configServerHost of
-              "*4" -> ipv4Addrs xs ++ ipv6Addrs xs
-              "!4" -> ipv4Addrs xs
-              "*6" -> ipv6Addrs xs ++ ipv4Addrs xs
-              "!6" -> ipv6Addrs xs
-              _    -> xs
-        ipv4Addrs = filter ((/=) AF_INET6 . addrFamily)
-        ipv6Addrs = filter ((==) AF_INET6 . addrFamily)
-
-      addrs <- getAddrInfo (Just $ defaultHints { addrSocketType = Stream }) (T.unpack <$> host) (Just . show $ configServerPort)
-      tryAddr `traverse` filterAddrs addrs
+reachMainApp :: AppConfig -> Socket -> IO (Either IOException ())
+reachMainApp AppConfig{..} appSock = try $ do
+  withSocketsDo $ bracket (pure appSock) close sendEmpty
   where
     sendEmpty sock = void $ send sock mempty
-    tryAddr :: AddrInfo -> IO (Either IOException ())
-    tryAddr addr = do
-      sock <- socket (addrFamily addr) (addrSocketType addr) (addrProtocol addr)
-      try $ do
-        connect sock $ addrAddress addr
-        withSocketsDo $ bracket (pure sock) close sendEmpty
diff --git a/src/PostgREST/App.hs b/src/PostgREST/App.hs
index 84e77c63a1..44046fc892 100644
--- a/src/PostgREST/App.hs
+++ b/src/PostgREST/App.hs
@@ -66,6 +66,7 @@ import qualified Data.ByteString.Char8 as BS
 import qualified Data.List             as L
 import qualified Data.Map              as Map (fromList)
 import qualified Network.HTTP.Types    as HTTP
+import qualified Network.Socket        as NS
 import qualified Network.Socket        as Socket
 import           Protolude             hiding (Handler)
 import           System.TimeIt         (timeItT)
@@ -88,33 +89,14 @@ run installHandlers maybeRunWithSocket appState = do
 
   let app = postgrest conf appState (AppState.connectionWorker appState)
 
-  case configServerUnixSocket of
-    Just socket ->
-      -- run the postgrest application with user defined socket. Only for UNIX systems
-      case maybeRunWithSocket of
-        Just runWithSocket -> do
-          AppState.logWithZTime appState $ "Listening on unix socket " <> show socket
-          runWithSocket (serverSettings conf) app configServerUnixSocketMode socket
-        Nothing ->
-          panic "Cannot run with unix socket on non-unix platforms."
-    Nothing ->
-      do
-        maddr <- resolveAddress configServerHost configServerPort
-        case maddr of
-          Nothing -> panic ("Could not resolve address " <> show configServerHost <> " port " <> show configServerPort)
-          Just addr -> do
-            sock <- E.bracketOnError (Socket.openSocket addr) Socket.close $ \sock -> do
-              Socket.bind sock $ Socket.addrAddress addr
-              pure sock
-            port <- Socket.socketPort sock
-            AppState.logWithZTime appState $ "Listening on port " <> show port
-            Warp.runSettingsSocket (serverSettings conf) sock app
-
-  where
-    resolveAddress host port = do
-      let hints = Socket.defaultHints { Socket.addrSocketType = Socket.Stream }
-      head <$> Socket.getAddrInfo (Just hints) (Just $ T.unpack host) (Just $ show port)
+  what <- case configServerUnixSocket of
+    Just path -> pure $ "unix socket " <> show path
+    Nothing   -> do
+      port <- NS.socketPort $ AppState.getSocketREST appState
+      pure $ "port " <> show port
+  AppState.logWithZTime appState $ "Listening on " <> what
 
+  Warp.runSettingsSocket (serverSettings conf) (AppState.getSocketREST appState) app
 
 serverSettings :: AppConfig -> Warp.Settings
 serverSettings AppConfig{..} =
diff --git a/src/PostgREST/AppState.hs b/src/PostgREST/AppState.hs
index 3183da80ed..2db3cd0902 100644
--- a/src/PostgREST/AppState.hs
+++ b/src/PostgREST/AppState.hs
@@ -14,6 +14,8 @@ module PostgREST.AppState
   , getRetryNextIn
   , getTime
   , getJwtCache
+  , getSocketREST
+  , getSocketAdmin
   , init
   , initWithPool
   , logWithZTime
@@ -32,12 +34,14 @@ import qualified Data.ByteString.Char8      as BS
 import qualified Data.ByteString.Lazy       as LBS
 import qualified Data.Cache                 as C
 import           Data.Either.Combinators    (whenLeft)
+import qualified Data.Text                  as T (unpack)
 import qualified Data.Text.Encoding         as T
 import           Hasql.Connection           (acquire)
 import qualified Hasql.Notifications        as SQL
 import qualified Hasql.Pool                 as SQL
 import qualified Hasql.Session              as SQL
 import qualified Hasql.Transaction.Sessions as SQL
+import qualified Network.Socket             as NS
 import qualified PostgREST.Error            as Error
 import           PostgREST.Version          (prettyVersion)
 
@@ -64,8 +68,11 @@ import PostgREST.SchemaCache             (SchemaCache,
                                           querySchemaCache)
 import PostgREST.SchemaCache.Identifiers (dumpQi)
 
+import Data.Streaming.Network (bindPath, bindPortTCP,
+                               bindRandomPortTCP)
+import Data.String            (IsString (..))
 import Protolude
-
+import System.Posix.Files     (setFileMode)
 
 data AuthResult = AuthResult
   { authClaims :: KM.KeyMap JSON.Value
@@ -99,15 +106,23 @@ data AppState = AppState
   , debounceLogAcquisitionTimeout :: IO ()
   -- | JWT Cache
   , jwtCache                      :: C.Cache ByteString AuthResult
+  -- | Network socket for REST API
+  , stateSocketREST               :: NS.Socket
+  -- | Network socket for the admin UI
+  , stateSocketAdmin              :: Maybe NS.Socket
   }
 
+type AppSockets = (NS.Socket, Maybe NS.Socket)
+
 init :: AppConfig -> IO AppState
 init conf = do
   pool <- initPool conf
-  initWithPool pool conf
+  (sock, adminSock) <- initSockets conf
+  state' <- initWithPool (sock, adminSock) pool conf
+  pure state' { stateSocketREST = sock, stateSocketAdmin = adminSock }
 
-initWithPool :: SQL.Pool -> AppConfig -> IO AppState
-initWithPool pool conf = do
+initWithPool :: AppSockets -> SQL.Pool -> AppConfig -> IO AppState
+initWithPool (sock, adminSock) pool conf = do
   appState <- AppState pool
     <$> newIORef minimumPgVersion -- assume we're in a supported version when starting, this will be corrected on a later step
     <*> newIORef Nothing
@@ -121,6 +136,8 @@ initWithPool pool conf = do
     <*> newIORef 0
     <*> pure (pure ())
     <*> C.newCache Nothing
+    <*> pure sock
+    <*> pure adminSock
 
 
   debLogTimeout <-
@@ -144,6 +161,37 @@ initWithPool pool conf = do
 destroy :: AppState -> IO ()
 destroy = destroyPool
 
+initSockets :: AppConfig -> IO AppSockets
+initSockets AppConfig{..} = do
+  let
+    cfg'usp = configServerUnixSocket
+    cfg'uspm = configServerUnixSocketMode
+    cfg'host = configServerHost
+    cfg'port = configServerPort
+    cfg'adminport = configAdminServerPort
+
+  (_port, sock) <- case cfg'usp of
+    Just usp -> do
+      sock <- bindPath usp
+      setFileMode (toS usp) cfg'uspm
+      pure (Nothing, sock)
+    Nothing -> do
+      (port, sock) <- if cfg'port /= 0 then do
+                          sock <- bindPortTCP cfg'port (fromString $ T.unpack cfg'host)
+                          pure (cfg'port, sock)
+                        else do
+                          (num, sock) <- bindRandomPortTCP (fromString $ T.unpack cfg'host)
+                          pure (num, sock)
+      pure (Just port, sock)
+
+  adminSock <- case cfg'adminport of
+    Just adminPort -> do
+      adminSock <- bindPortTCP adminPort (fromString $ T.unpack cfg'host)
+      pure $ Just adminSock
+    Nothing -> pure Nothing
+
+  pure (sock, adminSock)
+
 initPool :: AppConfig -> IO SQL.Pool
 initPool AppConfig{..} =
   SQL.acquire
@@ -204,6 +252,12 @@ getTime = stateGetTime
 getJwtCache :: AppState -> C.Cache ByteString AuthResult
 getJwtCache = jwtCache
 
+getSocketREST :: AppState -> NS.Socket
+getSocketREST = stateSocketREST
+
+getSocketAdmin :: AppState -> Maybe NS.Socket
+getSocketAdmin = stateSocketAdmin
+
 -- | Log to stderr with local time
 logWithZTime :: AppState -> Text -> IO ()
 logWithZTime appState txt = do

From 41df536ef7af7c248eea088fbedc415f8eba33ae Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Fri, 3 Nov 2023 17:39:25 +0100
Subject: [PATCH 04/28] fix leftover errors

---
 main/Main.hs           |  9 +--------
 src/PostgREST/Admin.hs | 12 +++++-------
 src/PostgREST/App.hs   |  7 ++-----
 src/PostgREST/CLI.hs   |  6 +++---
 src/PostgREST/Unix.hs  | 34 ++--------------------------------
 5 files changed, 13 insertions(+), 55 deletions(-)

diff --git a/main/Main.hs b/main/Main.hs
index 5d5e18a710..82ed56d270 100644
--- a/main/Main.hs
+++ b/main/Main.hs
@@ -17,7 +17,7 @@ main :: IO ()
 main = do
   setBuffering
   opts <- CLI.readCLIShowHelp
-  CLI.main installSignalHandlers runAppInSocket opts
+  CLI.main installSignalHandlers opts
 
 installSignalHandlers :: App.SignalHandlerInstaller
 #ifndef mingw32_HOST_OS
@@ -26,13 +26,6 @@ installSignalHandlers = Unix.installSignalHandlers
 installSignalHandlers _ = pass
 #endif
 
-runAppInSocket :: Maybe App.SocketRunner
-#ifndef mingw32_HOST_OS
-runAppInSocket = Just Unix.runAppWithSocket
-#else
-runAppInSocket = Nothing
-#endif
-
 setBuffering :: IO ()
 setBuffering = do
   -- LineBuffering: the entire output buffer is flushed whenever a newline is
diff --git a/src/PostgREST/Admin.hs b/src/PostgREST/Admin.hs
index 0cf447f60a..4fed31626e 100644
--- a/src/PostgREST/Admin.hs
+++ b/src/PostgREST/Admin.hs
@@ -1,11 +1,9 @@
-{-# LANGUAGE NamedFieldPuns  #-}
-{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE NamedFieldPuns #-}
 
 module PostgREST.Admin
   ( runAdmin
   ) where
 
-import qualified Data.Text                 as T
 import qualified Hasql.Session             as SQL
 import qualified Network.HTTP.Types.Status as HTTP
 import qualified Network.Wai               as Wai
@@ -27,7 +25,7 @@ import Protolude.Partial (fromJust)
 runAdmin :: AppConfig -> AppState -> Warp.Settings -> IO ()
 runAdmin conf@AppConfig{configAdminServerPort} appState settings =
   whenJust (AppState.getSocketAdmin appState) $ \adminSocket -> do
-    AppState.logWithZTime appState $ "Admin server listening on port " <> show (fromIntegral $ fromJust configAdminServerPort)
+    AppState.logWithZTime appState $ "Admin server listening on port " <> show (fromIntegral (fromJust configAdminServerPort) :: Integer)
     void . forkIO $ Warp.runSettingsSocket settings adminSocket adminApp
   where
     adminApp = admin appState conf
@@ -35,7 +33,7 @@ runAdmin conf@AppConfig{configAdminServerPort} appState settings =
 -- | PostgREST admin application
 admin :: AppState.AppState -> AppConfig -> Wai.Application
 admin appState appConfig req respond  = do
-  isMainAppReachable  <- isRight <$> reachMainApp appConfig (AppState.getSocketREST appState)
+  isMainAppReachable  <- isRight <$> reachMainApp (AppState.getSocketREST appState)
   isSchemaCacheLoaded <- isJust <$> AppState.getSchemaCache appState
   isConnectionUp      <-
     if configDbChannelEnabled appConfig
@@ -54,8 +52,8 @@ admin appState appConfig req respond  = do
 -- Note that it doesn't even send a valid HTTP request, we just want to check that the main app is accepting connections
 -- The code for resolving the "*4", "!4", "*6", "!6", "*" special values is taken from
 -- https://hackage.haskell.org/package/streaming-commons-0.2.2.4/docs/src/Data.Streaming.Network.html#bindPortGenEx
-reachMainApp :: AppConfig -> Socket -> IO (Either IOException ())
-reachMainApp AppConfig{..} appSock = try $ do
+reachMainApp :: Socket -> IO (Either IOException ())
+reachMainApp appSock = try $ do
   withSocketsDo $ bracket (pure appSock) close sendEmpty
   where
     sendEmpty sock = void $ send sock mempty
diff --git a/src/PostgREST/App.hs b/src/PostgREST/App.hs
index 44046fc892..26b34be67c 100644
--- a/src/PostgREST/App.hs
+++ b/src/PostgREST/App.hs
@@ -28,7 +28,6 @@ import Network.Wai.Handler.Warp (defaultSettings, setHost, setPort,
 import System.Posix.Types       (FileMode)
 
 import qualified Data.HashMap.Strict        as HM
-import qualified Data.Text                  as T (unpack)
 import qualified Data.Text.Encoding         as T
 import qualified Hasql.Transaction.Sessions as SQL
 import qualified Network.Wai                as Wai
@@ -61,13 +60,11 @@ import PostgREST.SchemaCache          (SchemaCache (..))
 import PostgREST.SchemaCache.Routine  (Routine (..))
 import PostgREST.Version              (docsVersion, prettyVersion)
 
-import qualified Control.Exception     as E
 import qualified Data.ByteString.Char8 as BS
 import qualified Data.List             as L
 import qualified Data.Map              as Map (fromList)
 import qualified Network.HTTP.Types    as HTTP
 import qualified Network.Socket        as NS
-import qualified Network.Socket        as Socket
 import           Protolude             hiding (Handler)
 import           System.TimeIt         (timeItT)
 
@@ -77,8 +74,8 @@ type SignalHandlerInstaller = AppState -> IO()
 
 type SocketRunner = Warp.Settings -> Wai.Application -> FileMode -> FilePath -> IO()
 
-run :: SignalHandlerInstaller -> Maybe SocketRunner -> AppState -> IO ()
-run installHandlers maybeRunWithSocket appState = do
+run :: SignalHandlerInstaller -> AppState -> IO ()
+run installHandlers appState = do
   conf@AppConfig{..} <- AppState.getConfig appState
   AppState.connectionWorker appState -- Loads the initial SchemaCache
   installHandlers appState
diff --git a/src/PostgREST/CLI.hs b/src/PostgREST/CLI.hs
index 9120d3e5ac..86148a36a8 100644
--- a/src/PostgREST/CLI.hs
+++ b/src/PostgREST/CLI.hs
@@ -29,8 +29,8 @@ import qualified PostgREST.Config   as Config
 import Protolude hiding (hPutStrLn)
 
 
-main :: App.SignalHandlerInstaller -> Maybe App.SocketRunner -> CLI -> IO ()
-main installSignalHandlers runAppWithSocket CLI{cliCommand, cliPath} = do
+main :: App.SignalHandlerInstaller -> CLI -> IO ()
+main installSignalHandlers CLI{cliCommand, cliPath} = do
   conf@AppConfig{..} <-
     either panic identity <$> Config.readAppConfig mempty cliPath Nothing mempty mempty
 
@@ -45,7 +45,7 @@ main installSignalHandlers runAppWithSocket CLI{cliCommand, cliPath} = do
         when configDbConfig $ AppState.reReadConfig True appState
         putStr . Config.toText =<< AppState.getConfig appState
       CmdDumpSchema -> putStrLn =<< dumpSchema appState
-      CmdRun -> App.run installSignalHandlers runAppWithSocket appState)
+      CmdRun -> App.run installSignalHandlers appState)
 
 -- | Dump SchemaCache schema to JSON
 dumpSchema :: AppState -> IO LBS.ByteString
diff --git a/src/PostgREST/Unix.hs b/src/PostgREST/Unix.hs
index 5cb09f7261..13becbefd3 100644
--- a/src/PostgREST/Unix.hs
+++ b/src/PostgREST/Unix.hs
@@ -1,44 +1,14 @@
 module PostgREST.Unix
-  ( runAppWithSocket
-  , installSignalHandlers
+  ( installSignalHandlers
   ) where
 
-import qualified Network.Socket           as Socket
-import qualified Network.Wai.Handler.Warp as Warp
-import qualified System.Posix.Signals     as Signals
-
-import Network.Wai        (Application)
-import System.Directory   (removeFile)
-import System.IO.Error    (isDoesNotExistError)
-import System.Posix.Files (setFileMode)
-import System.Posix.Types (FileMode)
+import qualified System.Posix.Signals as Signals
 
 import qualified PostgREST.AppState as AppState
 
 import Protolude
 
 
--- | Run the PostgREST application with user defined socket.
-runAppWithSocket :: Warp.Settings -> Application -> FileMode -> FilePath -> IO ()
-runAppWithSocket settings app socketFileMode socketFilePath =
-  bracket createAndBindSocket Socket.close $ \socket -> do
-    Socket.listen socket Socket.maxListenQueue
-    Warp.runSettingsSocket settings socket app
-  where
-    createAndBindSocket = do
-      deleteSocketFileIfExist socketFilePath
-      sock <- Socket.socket Socket.AF_UNIX Socket.Stream Socket.defaultProtocol
-      Socket.bind sock $ Socket.SockAddrUnix socketFilePath
-      setFileMode socketFilePath socketFileMode
-      return sock
-
-    deleteSocketFileIfExist path =
-      removeFile path `catch` handleDoesNotExist
-
-    handleDoesNotExist e
-      | isDoesNotExistError e = return ()
-      | otherwise = throwIO e
-
 -- | Set signal handlers, only for systems with signals
 installSignalHandlers :: AppState.AppState -> IO ()
 installSignalHandlers appState = do

From ab5bc73b01d456eb0d426012887e57c249bc8c33 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Mon, 6 Nov 2023 15:10:14 +0100
Subject: [PATCH 05/28] cabal: add streaming-commons

---
 postgrest.cabal | 1 +
 1 file changed, 1 insertion(+)

diff --git a/postgrest.cabal b/postgrest.cabal
index 80601ebf0b..736d155e5d 100644
--- a/postgrest.cabal
+++ b/postgrest.cabal
@@ -114,6 +114,7 @@ library
                     , regex-tdfa                >= 1.2.2 && < 1.4
                     , retry                     >= 0.7.4 && < 0.10
                     , scientific                >= 0.3.4 && < 0.4
+                    , streaming-commons         >= 0.1.1 && < 0.3
                     , swagger2                  >= 2.4 && < 2.9
                     , text                      >= 1.2.2 && < 1.3
                     , time                      >= 1.6 && < 1.12

From b47a35883502f64c6efc90d76d206009827e3596 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Mon, 6 Nov 2023 15:34:37 +0100
Subject: [PATCH 06/28] spec: fix tests

---
 src/PostgREST/AppState.hs | 1 +
 test/spec/Main.hs         | 5 +++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/PostgREST/AppState.hs b/src/PostgREST/AppState.hs
index 2db3cd0902..4fdfc8ce91 100644
--- a/src/PostgREST/AppState.hs
+++ b/src/PostgREST/AppState.hs
@@ -17,6 +17,7 @@ module PostgREST.AppState
   , getSocketREST
   , getSocketAdmin
   , init
+  , initSockets
   , initWithPool
   , logWithZTime
   , putSchemaCache
diff --git a/test/spec/Main.hs b/test/spec/Main.hs
index 86ced44310..db3a883099 100644
--- a/test/spec/Main.hs
+++ b/test/spec/Main.hs
@@ -73,11 +73,12 @@ main = do
 
   -- cached schema cache so most tests run fast
   baseSchemaCache <- loadSchemaCache pool testCfg
+  sockets <- AppState.initSockets testCfg
 
   let
     -- For tests that run with the same refSchemaCache
     app config = do
-      appState <- AppState.initWithPool pool config
+      appState <- AppState.initWithPool sockets pool config
       AppState.putPgVersion appState actualPgVersion
       AppState.putSchemaCache appState (Just baseSchemaCache)
       return ((), postgrest config appState $ pure ())
@@ -85,7 +86,7 @@ main = do
     -- For tests that run with a different SchemaCache(depends on configSchemas)
     appDbs config = do
       customSchemaCache <- loadSchemaCache pool config
-      appState <- AppState.initWithPool pool config
+      appState <- AppState.initWithPool sockets pool config
       AppState.putPgVersion appState actualPgVersion
       AppState.putSchemaCache appState (Just customSchemaCache)
       return ((), postgrest config appState $ pure ())

From 4e381285844de545efd267976fd069eec3a39111 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Thu, 9 Nov 2023 17:23:15 +0100
Subject: [PATCH 07/28] admin: fixed crash in reachMainApp

---
 src/PostgREST/Admin.hs | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/PostgREST/Admin.hs b/src/PostgREST/Admin.hs
index 4fed31626e..cff94b31fd 100644
--- a/src/PostgREST/Admin.hs
+++ b/src/PostgREST/Admin.hs
@@ -53,7 +53,15 @@ admin appState appConfig req respond  = do
 -- The code for resolving the "*4", "!4", "*6", "!6", "*" special values is taken from
 -- https://hackage.haskell.org/package/streaming-commons-0.2.2.4/docs/src/Data.Streaming.Network.html#bindPortGenEx
 reachMainApp :: Socket -> IO (Either IOException ())
-reachMainApp appSock = try $ do
-  withSocketsDo $ bracket (pure appSock) close sendEmpty
+reachMainApp appSock = do
+  sockAddr <- getSocketName appSock
+  sock <- socket (addrFamily sockAddr) Stream defaultProtocol
+  try $ do
+    connect sock sockAddr
+    withSocketsDo $ bracket (pure sock) close sendEmpty
   where
     sendEmpty sock = void $ send sock mempty
+    addrFamily (SockAddrInet _ _) = AF_INET
+    addrFamily (SockAddrInet6 _ _ _ _) = AF_INET6
+    addrFamily (SockAddrUnix _) = AF_UNIX
+

From 6081cd62562caa8e73d7c814ea69100973809761 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Thu, 9 Nov 2023 17:23:45 +0100
Subject: [PATCH 08/28] postgrest-style

---
 src/PostgREST/Admin.hs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/PostgREST/Admin.hs b/src/PostgREST/Admin.hs
index cff94b31fd..916522d173 100644
--- a/src/PostgREST/Admin.hs
+++ b/src/PostgREST/Admin.hs
@@ -61,7 +61,7 @@ reachMainApp appSock = do
     withSocketsDo $ bracket (pure sock) close sendEmpty
   where
     sendEmpty sock = void $ send sock mempty
-    addrFamily (SockAddrInet _ _) = AF_INET
+    addrFamily (SockAddrInet _ _)      = AF_INET
     addrFamily (SockAddrInet6 _ _ _ _) = AF_INET6
-    addrFamily (SockAddrUnix _) = AF_UNIX
+    addrFamily (SockAddrUnix _)        = AF_UNIX
 

From 394b8947facb82b7b30f992a4c46ee8d3bb45dd3 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Thu, 9 Nov 2023 17:30:31 +0100
Subject: [PATCH 09/28] postgrest-style

---
 src/PostgREST/Admin.hs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/PostgREST/Admin.hs b/src/PostgREST/Admin.hs
index 916522d173..64ef9372af 100644
--- a/src/PostgREST/Admin.hs
+++ b/src/PostgREST/Admin.hs
@@ -61,7 +61,7 @@ reachMainApp appSock = do
     withSocketsDo $ bracket (pure sock) close sendEmpty
   where
     sendEmpty sock = void $ send sock mempty
-    addrFamily (SockAddrInet _ _)      = AF_INET
-    addrFamily (SockAddrInet6 _ _ _ _) = AF_INET6
-    addrFamily (SockAddrUnix _)        = AF_UNIX
+    addrFamily (SockAddrInet _ _) = AF_INET
+    addrFamily (SockAddrInet6 {}) = AF_INET6
+    addrFamily (SockAddrUnix _)   = AF_UNIX
 

From 17306e3bb3f162245c09de7de39891eb5be9adcc Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Fri, 10 Nov 2023 17:58:39 +0100
Subject: [PATCH 10/28] get unix socket runtime check back

---
 src/PostgREST/AppState.hs | 42 ++++++++++++++++++++++++++++-----------
 1 file changed, 30 insertions(+), 12 deletions(-)

diff --git a/src/PostgREST/AppState.hs b/src/PostgREST/AppState.hs
index 4fdfc8ce91..da75e469cc 100644
--- a/src/PostgREST/AppState.hs
+++ b/src/PostgREST/AppState.hs
@@ -74,6 +74,9 @@ import Data.Streaming.Network (bindPath, bindPortTCP,
 import Data.String            (IsString (..))
 import Protolude
 import System.Posix.Files     (setFileMode)
+import Network.Socket (isUnixDomainSocketAvailable)
+import System.Directory (removeFile)
+import System.IO.Error (isDoesNotExistError)
 
 data AuthResult = AuthResult
   { authClaims :: KM.KeyMap JSON.Value
@@ -171,19 +174,21 @@ initSockets AppConfig{..} = do
     cfg'port = configServerPort
     cfg'adminport = configAdminServerPort
 
-  (_port, sock) <- case cfg'usp of
-    Just usp -> do
-      sock <- bindPath usp
-      setFileMode (toS usp) cfg'uspm
-      pure (Nothing, sock)
+  sock <- case cfg'usp of
+    Just path -> do
+      unless isUnixDomainSocketAvailable $ 
+        panic "Cannot run with unix socket on non-unix platforms. Consider deleting the `server-unix-socket` config entry in order to continue."
+      createAndBindSocket path cfg'uspm
     Nothing -> do
-      (port, sock) <- if cfg'port /= 0 then do
-                          sock <- bindPortTCP cfg'port (fromString $ T.unpack cfg'host)
-                          pure (cfg'port, sock)
-                        else do
-                          (num, sock) <- bindRandomPortTCP (fromString $ T.unpack cfg'host)
-                          pure (num, sock)
-      pure (Just port, sock)
+      (_, sock) <-
+        if cfg'port /= 0
+          then do
+            sock <- bindPortTCP cfg'port (fromString $ T.unpack cfg'host)
+            pure (cfg'port, sock)
+          else do
+            (num, sock) <- bindRandomPortTCP (fromString $ T.unpack cfg'host)
+            pure (num, sock)
+      pure sock
 
   adminSock <- case cfg'adminport of
     Just adminPort -> do
@@ -193,6 +198,19 @@ initSockets AppConfig{..} = do
 
   pure (sock, adminSock)
 
+  where
+    createAndBindSocket path mode = do
+      deleteSocketFileIfExist path
+      sock <- NS.socket NS.AF_UNIX NS.Stream NS.defaultProtocol
+      NS.bind sock $ NS.SockAddrUnix path
+      setFileMode path mode
+      return sock
+    deleteSocketFileIfExist path =
+      removeFile path `catch` handleDoesNotExist
+    handleDoesNotExist e
+      | isDoesNotExistError e = return ()
+      | otherwise = throwIO e
+
 initPool :: AppConfig -> IO SQL.Pool
 initPool AppConfig{..} =
   SQL.acquire

From 44075d40082a4ed7c8b4be2df7d262cbdbde9764 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Fri, 10 Nov 2023 18:01:59 +0100
Subject: [PATCH 11/28] postgrest-style

---
 src/PostgREST/AppState.hs | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/PostgREST/AppState.hs b/src/PostgREST/AppState.hs
index da75e469cc..a308387914 100644
--- a/src/PostgREST/AppState.hs
+++ b/src/PostgREST/AppState.hs
@@ -69,14 +69,13 @@ import PostgREST.SchemaCache             (SchemaCache,
                                           querySchemaCache)
 import PostgREST.SchemaCache.Identifiers (dumpQi)
 
-import Data.Streaming.Network (bindPath, bindPortTCP,
-                               bindRandomPortTCP)
+import Data.Streaming.Network (bindPortTCP, bindRandomPortTCP)
 import Data.String            (IsString (..))
+import Network.Socket         (isUnixDomainSocketAvailable)
 import Protolude
+import System.Directory       (removeFile)
+import System.IO.Error        (isDoesNotExistError)
 import System.Posix.Files     (setFileMode)
-import Network.Socket (isUnixDomainSocketAvailable)
-import System.Directory (removeFile)
-import System.IO.Error (isDoesNotExistError)
 
 data AuthResult = AuthResult
   { authClaims :: KM.KeyMap JSON.Value
@@ -176,7 +175,7 @@ initSockets AppConfig{..} = do
 
   sock <- case cfg'usp of
     Just path -> do
-      unless isUnixDomainSocketAvailable $ 
+      unless isUnixDomainSocketAvailable $
         panic "Cannot run with unix socket on non-unix platforms. Consider deleting the `server-unix-socket` config entry in order to continue."
       createAndBindSocket path cfg'uspm
     Nothing -> do

From 364f2d2cc96b732b3c1049472736563c1fe1fd5b Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Mon, 13 Nov 2023 18:30:11 +0100
Subject: [PATCH 12/28] bind then listen

---
 src/PostgREST/AppState.hs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/PostgREST/AppState.hs b/src/PostgREST/AppState.hs
index a308387914..9576fd818f 100644
--- a/src/PostgREST/AppState.hs
+++ b/src/PostgREST/AppState.hs
@@ -202,6 +202,7 @@ initSockets AppConfig{..} = do
       deleteSocketFileIfExist path
       sock <- NS.socket NS.AF_UNIX NS.Stream NS.defaultProtocol
       NS.bind sock $ NS.SockAddrUnix path
+      NS.listen sock (max 2048 NS.maxListenQueue)
       setFileMode path mode
       return sock
     deleteSocketFileIfExist path =

From 759094a1c7e649e42251e18d54e94fab11d0fe99 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Tue, 14 Nov 2023 17:16:33 +0100
Subject: [PATCH 13/28] use setPerms from unix-compat

---
 postgrest.cabal           |  1 +
 src/PostgREST/App.hs      |  4 ++--
 src/PostgREST/AppState.hs | 18 +---------------
 src/PostgREST/Unix.hs     | 45 ++++++++++++++++++++++++++-------------
 4 files changed, 34 insertions(+), 34 deletions(-)

diff --git a/postgrest.cabal b/postgrest.cabal
index 736d155e5d..3aee90399f 100644
--- a/postgrest.cabal
+++ b/postgrest.cabal
@@ -120,6 +120,7 @@ library
                     , time                      >= 1.6 && < 1.12
                     , timeit                    >= 2.0 && < 2.1
                     , unordered-containers      >= 0.2.8 && < 0.3
+                    , unix-compat               >= 0.7 && < 0.8
                     , vault                     >= 0.3.1.5 && < 0.4
                     , vector                    >= 0.11 && < 0.14
                     , wai                       >= 3.2.1 && < 3.3
diff --git a/src/PostgREST/App.hs b/src/PostgREST/App.hs
index 26b34be67c..6fd52744c7 100644
--- a/src/PostgREST/App.hs
+++ b/src/PostgREST/App.hs
@@ -70,7 +70,7 @@ import           System.TimeIt         (timeItT)
 
 type Handler = ExceptT Error
 
-type SignalHandlerInstaller = AppState -> IO()
+type SignalHandlerInstaller = ThreadId -> IO () -> IO ()-> IO()
 
 type SocketRunner = Warp.Settings -> Wai.Application -> FileMode -> FilePath -> IO()
 
@@ -78,7 +78,7 @@ run :: SignalHandlerInstaller -> AppState -> IO ()
 run installHandlers appState = do
   conf@AppConfig{..} <- AppState.getConfig appState
   AppState.connectionWorker appState -- Loads the initial SchemaCache
-  installHandlers appState
+  installHandlers (AppState.getMainThreadId appState) (AppState.connectionWorker appState) (AppState.reReadConfig False appState)
   -- reload schema cache + config on NOTIFY
   AppState.runListener conf appState
 
diff --git a/src/PostgREST/AppState.hs b/src/PostgREST/AppState.hs
index 9576fd818f..ce8672ddab 100644
--- a/src/PostgREST/AppState.hs
+++ b/src/PostgREST/AppState.hs
@@ -68,14 +68,12 @@ import PostgREST.Config.PgVersion        (PgVersion (..),
 import PostgREST.SchemaCache             (SchemaCache,
                                           querySchemaCache)
 import PostgREST.SchemaCache.Identifiers (dumpQi)
+import PostgREST.Unix                    (createAndBindSocket)
 
 import Data.Streaming.Network (bindPortTCP, bindRandomPortTCP)
 import Data.String            (IsString (..))
 import Network.Socket         (isUnixDomainSocketAvailable)
 import Protolude
-import System.Directory       (removeFile)
-import System.IO.Error        (isDoesNotExistError)
-import System.Posix.Files     (setFileMode)
 
 data AuthResult = AuthResult
   { authClaims :: KM.KeyMap JSON.Value
@@ -197,20 +195,6 @@ initSockets AppConfig{..} = do
 
   pure (sock, adminSock)
 
-  where
-    createAndBindSocket path mode = do
-      deleteSocketFileIfExist path
-      sock <- NS.socket NS.AF_UNIX NS.Stream NS.defaultProtocol
-      NS.bind sock $ NS.SockAddrUnix path
-      NS.listen sock (max 2048 NS.maxListenQueue)
-      setFileMode path mode
-      return sock
-    deleteSocketFileIfExist path =
-      removeFile path `catch` handleDoesNotExist
-    handleDoesNotExist e
-      | isDoesNotExistError e = return ()
-      | otherwise = throwIO e
-
 initPool :: AppConfig -> IO SQL.Pool
 initPool AppConfig{..} =
   SQL.acquire
diff --git a/src/PostgREST/Unix.hs b/src/PostgREST/Unix.hs
index 13becbefd3..c5d956a656 100644
--- a/src/PostgREST/Unix.hs
+++ b/src/PostgREST/Unix.hs
@@ -1,27 +1,42 @@
 module PostgREST.Unix
   ( installSignalHandlers
+  , createAndBindSocket
   ) where
 
-import qualified System.Posix.Signals as Signals
-
-import qualified PostgREST.AppState as AppState
-
-import Protolude
+import qualified System.Posix.Signals     as Signals
+import           System.Posix.Types       (FileMode)
+import           System.PosixCompat.Files (setFileMode)
 
+import           Data.String      (String)
+import qualified Network.Socket   as NS
+import           Protolude
+import           System.Directory (Permissions, removeFile,
+                                   setOwnerReadable, setPermissions)
+import           System.IO.Error  (isDoesNotExistError)
 
 -- | Set signal handlers, only for systems with signals
-installSignalHandlers :: AppState.AppState -> IO ()
-installSignalHandlers appState = do
-  let interrupt = throwTo (AppState.getMainThreadId appState) UserInterrupt
+installSignalHandlers :: ThreadId -> IO () -> IO () -> IO ()
+installSignalHandlers tid usr1 usr2 = do
+  let interrupt = throwTo tid UserInterrupt
   install Signals.sigINT interrupt
   install Signals.sigTERM interrupt
-
-  -- The SIGUSR1 signal updates the internal 'SchemaCache' by running
-  -- 'connectionWorker' exactly as before.
-  install Signals.sigUSR1 $ AppState.connectionWorker appState
-
-  -- Re-read the config on SIGUSR2
-  install Signals.sigUSR2 $ AppState.reReadConfig False appState
+  install Signals.sigUSR1 usr1
+  install Signals.sigUSR2 usr2
   where
     install signal handler =
       void $ Signals.installHandler signal (Signals.Catch handler) Nothing
+
+createAndBindSocket :: String -> FileMode -> IO NS.Socket
+createAndBindSocket path mode = do
+  deleteSocketFileIfExist path
+  sock <- NS.socket NS.AF_UNIX NS.Stream NS.defaultProtocol
+  NS.bind sock $ NS.SockAddrUnix path
+  NS.listen sock (max 2048 NS.maxListenQueue)
+  setFileMode path mode
+  return sock
+  where
+    deleteSocketFileIfExist path =
+      removeFile path `catch` handleDoesNotExist
+    handleDoesNotExist e
+      | isDoesNotExistError e = return ()
+      | otherwise = throwIO e

From 95f665fe739f448a69b1e3b1d47d8992eced990e Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Tue, 14 Nov 2023 17:24:06 +0100
Subject: [PATCH 14/28] style

---
 src/PostgREST/Unix.hs | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/PostgREST/Unix.hs b/src/PostgREST/Unix.hs
index c5d956a656..cd9b0f1e7e 100644
--- a/src/PostgREST/Unix.hs
+++ b/src/PostgREST/Unix.hs
@@ -10,8 +10,7 @@ import           System.PosixCompat.Files (setFileMode)
 import           Data.String      (String)
 import qualified Network.Socket   as NS
 import           Protolude
-import           System.Directory (Permissions, removeFile,
-                                   setOwnerReadable, setPermissions)
+import           System.Directory (removeFile)
 import           System.IO.Error  (isDoesNotExistError)
 
 -- | Set signal handlers, only for systems with signals
@@ -35,8 +34,8 @@ createAndBindSocket path mode = do
   setFileMode path mode
   return sock
   where
-    deleteSocketFileIfExist path =
-      removeFile path `catch` handleDoesNotExist
+    deleteSocketFileIfExist path' =
+      removeFile path' `catch` handleDoesNotExist
     handleDoesNotExist e
       | isDoesNotExistError e = return ()
       | otherwise = throwIO e

From 50925df57129ce462fb828c7557b747177977d24 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Tue, 14 Nov 2023 17:30:23 +0100
Subject: [PATCH 15/28] pin unix-compat for warp

---
 postgrest.cabal | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/postgrest.cabal b/postgrest.cabal
index 3aee90399f..f8703cc74b 100644
--- a/postgrest.cabal
+++ b/postgrest.cabal
@@ -120,7 +120,7 @@ library
                     , time                      >= 1.6 && < 1.12
                     , timeit                    >= 2.0 && < 2.1
                     , unordered-containers      >= 0.2.8 && < 0.3
-                    , unix-compat               >= 0.7 && < 0.8
+                    , unix-compat               == 0.5.4
                     , vault                     >= 0.3.1.5 && < 0.4
                     , vector                    >= 0.11 && < 0.14
                     , wai                       >= 3.2.1 && < 3.3

From 7d21a4993707cfa4da01f532016c80e71605a1f1 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Wed, 15 Nov 2023 16:04:50 +0100
Subject: [PATCH 16/28] put Unix specifics to Postgrest.Unix

---
 main/Main.hs              | 16 +---------------
 src/PostgREST/App.hs      | 16 +++++-----------
 src/PostgREST/AppState.hs |  4 ++--
 src/PostgREST/CLI.hs      |  6 +++---
 src/PostgREST/Unix.hs     | 12 +++++++++---
 5 files changed, 20 insertions(+), 34 deletions(-)

diff --git a/main/Main.hs b/main/Main.hs
index 82ed56d270..4d23125184 100644
--- a/main/Main.hs
+++ b/main/Main.hs
@@ -1,30 +1,16 @@
-{-# LANGUAGE CPP #-}
-
 module Main (main) where
 
 import System.IO (BufferMode (..), hSetBuffering)
 
-import qualified PostgREST.App as App
 import qualified PostgREST.CLI as CLI
 
 import Protolude
 
-#ifndef mingw32_HOST_OS
-import qualified PostgREST.Unix as Unix
-#endif
-
 main :: IO ()
 main = do
   setBuffering
   opts <- CLI.readCLIShowHelp
-  CLI.main installSignalHandlers opts
-
-installSignalHandlers :: App.SignalHandlerInstaller
-#ifndef mingw32_HOST_OS
-installSignalHandlers = Unix.installSignalHandlers
-#else
-installSignalHandlers _ = pass
-#endif
+  CLI.main opts
 
 setBuffering :: IO ()
 setBuffering = do
diff --git a/src/PostgREST/App.hs b/src/PostgREST/App.hs
index 6fd52744c7..93a055abad 100644
--- a/src/PostgREST/App.hs
+++ b/src/PostgREST/App.hs
@@ -12,9 +12,7 @@ Some of its functionality includes:
 {-# LANGUAGE NamedFieldPuns  #-}
 {-# LANGUAGE RecordWildCards #-}
 module PostgREST.App
-  ( SignalHandlerInstaller
-  , SocketRunner
-  , postgrest
+  ( postgrest
   , run
   ) where
 
@@ -25,7 +23,6 @@ import Data.Maybe               (fromJust)
 import Data.String              (IsString (..))
 import Network.Wai.Handler.Warp (defaultSettings, setHost, setPort,
                                  setServerName)
-import System.Posix.Types       (FileMode)
 
 import qualified Data.HashMap.Strict        as HM
 import qualified Data.Text.Encoding         as T
@@ -44,6 +41,7 @@ import qualified PostgREST.Logger           as Logger
 import qualified PostgREST.Plan             as Plan
 import qualified PostgREST.Query            as Query
 import qualified PostgREST.Response         as Response
+import qualified PostgREST.Unix             as Unix (installSignalHandlers)
 
 import PostgREST.ApiRequest           (Action (..), ApiRequest (..),
                                        Mutation (..), Target (..))
@@ -70,15 +68,11 @@ import           System.TimeIt         (timeItT)
 
 type Handler = ExceptT Error
 
-type SignalHandlerInstaller = ThreadId -> IO () -> IO ()-> IO()
-
-type SocketRunner = Warp.Settings -> Wai.Application -> FileMode -> FilePath -> IO()
-
-run :: SignalHandlerInstaller -> AppState -> IO ()
-run installHandlers appState = do
+run :: AppState -> IO ()
+run appState = do
   conf@AppConfig{..} <- AppState.getConfig appState
   AppState.connectionWorker appState -- Loads the initial SchemaCache
-  installHandlers (AppState.getMainThreadId appState) (AppState.connectionWorker appState) (AppState.reReadConfig False appState)
+  Unix.installSignalHandlers (AppState.getMainThreadId appState) (AppState.connectionWorker appState) (AppState.reReadConfig False appState)
   -- reload schema cache + config on NOTIFY
   AppState.runListener conf appState
 
diff --git a/src/PostgREST/AppState.hs b/src/PostgREST/AppState.hs
index ce8672ddab..e6cd413003 100644
--- a/src/PostgREST/AppState.hs
+++ b/src/PostgREST/AppState.hs
@@ -68,7 +68,7 @@ import PostgREST.Config.PgVersion        (PgVersion (..),
 import PostgREST.SchemaCache             (SchemaCache,
                                           querySchemaCache)
 import PostgREST.SchemaCache.Identifiers (dumpQi)
-import PostgREST.Unix                    (createAndBindSocket)
+import PostgREST.Unix                    (createAndBindDomainSocket)
 
 import Data.Streaming.Network (bindPortTCP, bindRandomPortTCP)
 import Data.String            (IsString (..))
@@ -175,7 +175,7 @@ initSockets AppConfig{..} = do
     Just path -> do
       unless isUnixDomainSocketAvailable $
         panic "Cannot run with unix socket on non-unix platforms. Consider deleting the `server-unix-socket` config entry in order to continue."
-      createAndBindSocket path cfg'uspm
+      createAndBindDomainSocket path cfg'uspm
     Nothing -> do
       (_, sock) <-
         if cfg'port /= 0
diff --git a/src/PostgREST/CLI.hs b/src/PostgREST/CLI.hs
index 86148a36a8..39d4f49dfd 100644
--- a/src/PostgREST/CLI.hs
+++ b/src/PostgREST/CLI.hs
@@ -29,8 +29,8 @@ import qualified PostgREST.Config   as Config
 import Protolude hiding (hPutStrLn)
 
 
-main :: App.SignalHandlerInstaller -> CLI -> IO ()
-main installSignalHandlers CLI{cliCommand, cliPath} = do
+main :: CLI -> IO ()
+main CLI{cliCommand, cliPath} = do
   conf@AppConfig{..} <-
     either panic identity <$> Config.readAppConfig mempty cliPath Nothing mempty mempty
 
@@ -45,7 +45,7 @@ main installSignalHandlers CLI{cliCommand, cliPath} = do
         when configDbConfig $ AppState.reReadConfig True appState
         putStr . Config.toText =<< AppState.getConfig appState
       CmdDumpSchema -> putStrLn =<< dumpSchema appState
-      CmdRun -> App.run installSignalHandlers appState)
+      CmdRun -> App.run appState)
 
 -- | Dump SchemaCache schema to JSON
 dumpSchema :: AppState -> IO LBS.ByteString
diff --git a/src/PostgREST/Unix.hs b/src/PostgREST/Unix.hs
index cd9b0f1e7e..ec1b5bab31 100644
--- a/src/PostgREST/Unix.hs
+++ b/src/PostgREST/Unix.hs
@@ -1,6 +1,8 @@
+{-# LANGUAGE CPP #-}
+
 module PostgREST.Unix
   ( installSignalHandlers
-  , createAndBindSocket
+  , createAndBindDomainSocket
   ) where
 
 import qualified System.Posix.Signals     as Signals
@@ -15,6 +17,7 @@ import           System.IO.Error  (isDoesNotExistError)
 
 -- | Set signal handlers, only for systems with signals
 installSignalHandlers :: ThreadId -> IO () -> IO () -> IO ()
+#ifndef mingw32_HOST_OS
 installSignalHandlers tid usr1 usr2 = do
   let interrupt = throwTo tid UserInterrupt
   install Signals.sigINT interrupt
@@ -24,9 +27,12 @@ installSignalHandlers tid usr1 usr2 = do
   where
     install signal handler =
       void $ Signals.installHandler signal (Signals.Catch handler) Nothing
+#else
+installSignalHandlers _ = pass
+#endif
 
-createAndBindSocket :: String -> FileMode -> IO NS.Socket
-createAndBindSocket path mode = do
+createAndBindDomainSocket :: String -> FileMode -> IO NS.Socket
+createAndBindDomainSocket path mode = do
   deleteSocketFileIfExist path
   sock <- NS.socket NS.AF_UNIX NS.Stream NS.defaultProtocol
   NS.bind sock $ NS.SockAddrUnix path

From 846bf5d5675ab87e432f4d26545d0d61a49d076d Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Wed, 15 Nov 2023 16:11:19 +0100
Subject: [PATCH 17/28] forgot .cabal

---
 postgrest.cabal | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/postgrest.cabal b/postgrest.cabal
index f8703cc74b..35826a4ff0 100644
--- a/postgrest.cabal
+++ b/postgrest.cabal
@@ -64,6 +64,7 @@ library
                       PostgREST.Plan.ReadPlan
                       PostgREST.Plan.Types
                       PostgREST.RangeQuery
+                      PostgREST.Unix
                       PostgREST.ApiRequest
                       PostgREST.ApiRequest.Preferences
                       PostgREST.ApiRequest.QueryParams
@@ -120,6 +121,7 @@ library
                     , time                      >= 1.6 && < 1.12
                     , timeit                    >= 2.0 && < 2.1
                     , unordered-containers      >= 0.2.8 && < 0.3
+                    -- pinning unix-compat to match one's version in warp
                     , unix-compat               == 0.5.4
                     , vault                     >= 0.3.1.5 && < 0.4
                     , vector                    >= 0.11 && < 0.14
@@ -151,8 +153,6 @@ library
     build-depends:
       unix
       , directory >= 1.2.6 && < 1.4
-    exposed-modules:
-      PostgREST.Unix
 
 executable postgrest
   default-language:   Haskell2010
@@ -162,6 +162,7 @@ executable postgrest
   main-is:            Main.hs
   build-depends:      base                >= 4.9 && < 4.17
                     , containers          >= 0.5.7 && < 0.7
+                    , network                   >= 2.6 && < 3.2
                     , postgrest
                     , protolude           >= 0.3.1 && < 0.4
   ghc-options:        -threaded -rtsopts "-with-rtsopts=-N -I0 -qg"

From 30495e6b64bd8bbdf7d471e42aa2af6d9ba68b42 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Wed, 15 Nov 2023 16:21:15 +0100
Subject: [PATCH 18/28] fix windows build

---
 postgrest.cabal       | 2 +-
 src/PostgREST/Unix.hs | 8 +++++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/postgrest.cabal b/postgrest.cabal
index 35826a4ff0..3b160e7688 100644
--- a/postgrest.cabal
+++ b/postgrest.cabal
@@ -90,6 +90,7 @@ library
                     , containers                >= 0.5.7 && < 0.7
                     , contravariant-extras      >= 0.3.3 && < 0.4
                     , cookie                    >= 0.4.2 && < 0.5
+                    , directory                 >= 1.2.6 && < 1.4
                     , either                    >= 4.4.1 && < 5.1
                     , extra                     >= 1.7.0 && < 2.0
                     , fuzzyset                  >= 0.2.3
@@ -152,7 +153,6 @@ library
   if !os(windows)
     build-depends:
       unix
-      , directory >= 1.2.6 && < 1.4
 
 executable postgrest
   default-language:   Haskell2010
diff --git a/src/PostgREST/Unix.hs b/src/PostgREST/Unix.hs
index ec1b5bab31..a38da26369 100644
--- a/src/PostgREST/Unix.hs
+++ b/src/PostgREST/Unix.hs
@@ -5,9 +5,11 @@ module PostgREST.Unix
   , createAndBindDomainSocket
   ) where
 
-import qualified System.Posix.Signals     as Signals
-import           System.Posix.Types       (FileMode)
-import           System.PosixCompat.Files (setFileMode)
+#ifndef mingw32_HOST_OS
+import qualified System.Posix.Signals as Signals
+#endif
+import System.Posix.Types       (FileMode)
+import System.PosixCompat.Files (setFileMode)
 
 import           Data.String      (String)
 import qualified Network.Socket   as NS

From 93c39536f1fb8ad6941cd2b478afa6ca86d8b4b8 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Thu, 16 Nov 2023 12:35:05 +0100
Subject: [PATCH 19/28] fix installSignalHandlers stub

---
 src/PostgREST/Unix.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/PostgREST/Unix.hs b/src/PostgREST/Unix.hs
index a38da26369..46bfec5fe4 100644
--- a/src/PostgREST/Unix.hs
+++ b/src/PostgREST/Unix.hs
@@ -30,7 +30,7 @@ installSignalHandlers tid usr1 usr2 = do
     install signal handler =
       void $ Signals.installHandler signal (Signals.Catch handler) Nothing
 #else
-installSignalHandlers _ = pass
+installSignalHandlers _ _ _ = pass
 #endif
 
 createAndBindDomainSocket :: String -> FileMode -> IO NS.Socket

From b09804edf9cae3ef96f4674a0bfc18c2ee138b02 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Fri, 17 Nov 2023 14:46:36 +0100
Subject: [PATCH 20/28] move domain socket avail check to Unix

---
 src/PostgREST/AppState.hs | 9 ++++-----
 src/PostgREST/Unix.hs     | 4 ++++
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/PostgREST/AppState.hs b/src/PostgREST/AppState.hs
index e6cd413003..77c8633eff 100644
--- a/src/PostgREST/AppState.hs
+++ b/src/PostgREST/AppState.hs
@@ -72,7 +72,6 @@ import PostgREST.Unix                    (createAndBindDomainSocket)
 
 import Data.Streaming.Network (bindPortTCP, bindRandomPortTCP)
 import Data.String            (IsString (..))
-import Network.Socket         (isUnixDomainSocketAvailable)
 import Protolude
 
 data AuthResult = AuthResult
@@ -172,10 +171,9 @@ initSockets AppConfig{..} = do
     cfg'adminport = configAdminServerPort
 
   sock <- case cfg'usp of
-    Just path -> do
-      unless isUnixDomainSocketAvailable $
-        panic "Cannot run with unix socket on non-unix platforms. Consider deleting the `server-unix-socket` config entry in order to continue."
-      createAndBindDomainSocket path cfg'uspm
+    -- I'm not using `streaming-commons`' bindPath function here because it's not defined for Windows, 
+    -- but we need to have runtime error if we try to use it in Windows, not compile time error
+    Just path -> createAndBindDomainSocket path cfg'uspm
     Nothing -> do
       (_, sock) <-
         if cfg'port /= 0
@@ -183,6 +181,7 @@ initSockets AppConfig{..} = do
             sock <- bindPortTCP cfg'port (fromString $ T.unpack cfg'host)
             pure (cfg'port, sock)
           else do
+            -- explicitly bind to a random port, returning bound port number
             (num, sock) <- bindRandomPortTCP (fromString $ T.unpack cfg'host)
             pure (num, sock)
       pure sock
diff --git a/src/PostgREST/Unix.hs b/src/PostgREST/Unix.hs
index 46bfec5fe4..2027cac023 100644
--- a/src/PostgREST/Unix.hs
+++ b/src/PostgREST/Unix.hs
@@ -33,8 +33,12 @@ installSignalHandlers tid usr1 usr2 = do
 installSignalHandlers _ _ _ = pass
 #endif
 
+-- | Create a unix domain socket and bind it to the given path.
+-- | The socket file will be deleted if it already exists.
 createAndBindDomainSocket :: String -> FileMode -> IO NS.Socket
 createAndBindDomainSocket path mode = do
+  unless NS.isUnixDomainSocketAvailable $
+    panic "Cannot run with unix socket on non-unix platforms. Consider deleting the `server-unix-socket` config entry in order to continue."
   deleteSocketFileIfExist path
   sock <- NS.socket NS.AF_UNIX NS.Stream NS.defaultProtocol
   NS.bind sock $ NS.SockAddrUnix path

From b9642a3a1132a18fe125402bed6111074e039c9d Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Fri, 17 Nov 2023 14:47:28 +0100
Subject: [PATCH 21/28] exe: drop network from deps

---
 postgrest.cabal | 1 -
 1 file changed, 1 deletion(-)

diff --git a/postgrest.cabal b/postgrest.cabal
index 3b160e7688..e1b848c112 100644
--- a/postgrest.cabal
+++ b/postgrest.cabal
@@ -162,7 +162,6 @@ executable postgrest
   main-is:            Main.hs
   build-depends:      base                >= 4.9 && < 4.17
                     , containers          >= 0.5.7 && < 0.7
-                    , network                   >= 2.6 && < 3.2
                     , postgrest
                     , protolude           >= 0.3.1 && < 0.4
   ghc-options:        -threaded -rtsopts "-with-rtsopts=-N -I0 -qg"

From 7fe26dcfce7abb32ffb166d4aed263f8d03e9ce8 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Fri, 17 Nov 2023 15:04:26 +0100
Subject: [PATCH 22/28] style

---
 src/PostgREST/AppState.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/PostgREST/AppState.hs b/src/PostgREST/AppState.hs
index 77c8633eff..8fff8edc85 100644
--- a/src/PostgREST/AppState.hs
+++ b/src/PostgREST/AppState.hs
@@ -171,7 +171,7 @@ initSockets AppConfig{..} = do
     cfg'adminport = configAdminServerPort
 
   sock <- case cfg'usp of
-    -- I'm not using `streaming-commons`' bindPath function here because it's not defined for Windows, 
+    -- I'm not using `streaming-commons`' bindPath function here because it's not defined for Windows,
     -- but we need to have runtime error if we try to use it in Windows, not compile time error
     Just path -> createAndBindDomainSocket path cfg'uspm
     Nothing -> do

From e56e857b349d192e1a81fa5a6b234cf17722bbb9 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Wed, 22 Nov 2023 17:34:44 +0100
Subject: [PATCH 23/28] unpin unix-compat

---
 postgrest.cabal | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/postgrest.cabal b/postgrest.cabal
index e1b848c112..262fc956ba 100644
--- a/postgrest.cabal
+++ b/postgrest.cabal
@@ -122,8 +122,7 @@ library
                     , time                      >= 1.6 && < 1.12
                     , timeit                    >= 2.0 && < 2.1
                     , unordered-containers      >= 0.2.8 && < 0.3
-                    -- pinning unix-compat to match one's version in warp
-                    , unix-compat               == 0.5.4
+                    , unix-compat
                     , vault                     >= 0.3.1.5 && < 0.4
                     , vector                    >= 0.11 && < 0.14
                     , wai                       >= 3.2.1 && < 3.3

From 56d524c4825fde31e05d6306a38890b9c74fb5fe Mon Sep 17 00:00:00 2001
From: Steve Chavez <stevechavezast@gmail.com>
Date: Wed, 22 Nov 2023 12:30:44 -0500
Subject: [PATCH 24/28] Update postgrest.cabal

---
 postgrest.cabal | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/postgrest.cabal b/postgrest.cabal
index 262fc956ba..b97d88a2ba 100644
--- a/postgrest.cabal
+++ b/postgrest.cabal
@@ -122,7 +122,7 @@ library
                     , time                      >= 1.6 && < 1.12
                     , timeit                    >= 2.0 && < 2.1
                     , unordered-containers      >= 0.2.8 && < 0.3
-                    , unix-compat
+                    , unix-compat >= 0.6 && < 0.7
                     , vault                     >= 0.3.1.5 && < 0.4
                     , vector                    >= 0.11 && < 0.14
                     , wai                       >= 3.2.1 && < 3.3

From 9df15e10246d3fe2c517f0c9316d94f4d8112785 Mon Sep 17 00:00:00 2001
From: Steve Chavez <stevechavezast@gmail.com>
Date: Wed, 22 Nov 2023 12:51:47 -0500
Subject: [PATCH 25/28] Update postgrest.cabal

---
 postgrest.cabal | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/postgrest.cabal b/postgrest.cabal
index b97d88a2ba..c2d692f06e 100644
--- a/postgrest.cabal
+++ b/postgrest.cabal
@@ -122,7 +122,7 @@ library
                     , time                      >= 1.6 && < 1.12
                     , timeit                    >= 2.0 && < 2.1
                     , unordered-containers      >= 0.2.8 && < 0.3
-                    , unix-compat >= 0.6 && < 0.7
+                    , unix-compat               >= 0.5.4 && < 0.6
                     , vault                     >= 0.3.1.5 && < 0.4
                     , vector                    >= 0.11 && < 0.14
                     , wai                       >= 3.2.1 && < 3.3

From 77a93450eec9374b7ad199ccd6f393efe3d058f0 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Thu, 23 Nov 2023 11:06:04 +0100
Subject: [PATCH 26/28] test/io: test random port assignment

---
 test/io/test_io.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/test/io/test_io.py b/test/io/test_io.py
index 9209463d13..efc76d49ca 100644
--- a/test/io/test_io.py
+++ b/test/io/test_io.py
@@ -196,6 +196,11 @@ def sleep():
 
         t.join()
 
+def test_random_port_bound(defaultenv):
+    "PostgREST should bind to a random port when PGRST_SERVER_PORT is 0."
+
+    with run(env=defaultenv, port="0") as postgrest:
+        assert True # liveness check is done by run(), so we just need to check that it doesn't fail
 
 def test_app_settings_reload(tmp_path, defaultenv):
     "App settings should be reloaded from file when PostgREST is sent SIGUSR2."

From 904f01d58d8134035c6b2c60a17979fa16da3e53 Mon Sep 17 00:00:00 2001
From: Andrei Dziahel <develop7@develop7.info>
Date: Thu, 23 Nov 2023 11:23:40 +0100
Subject: [PATCH 27/28] style

---
 test/io/test_io.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/test/io/test_io.py b/test/io/test_io.py
index efc76d49ca..3993de751b 100644
--- a/test/io/test_io.py
+++ b/test/io/test_io.py
@@ -196,11 +196,13 @@ def sleep():
 
         t.join()
 
+
 def test_random_port_bound(defaultenv):
     "PostgREST should bind to a random port when PGRST_SERVER_PORT is 0."
 
     with run(env=defaultenv, port="0") as postgrest:
-        assert True # liveness check is done by run(), so we just need to check that it doesn't fail
+        assert True  # liveness check is done by run(), so we just need to check that it doesn't fail
+
 
 def test_app_settings_reload(tmp_path, defaultenv):
     "App settings should be reloaded from file when PostgREST is sent SIGUSR2."

From bee8c8b0d55f65f81acb9e3913f40f6d7000e8a7 Mon Sep 17 00:00:00 2001
From: steve-chavez <stevechavezast@gmail.com>
Date: Thu, 23 Nov 2023 17:53:52 -0500
Subject: [PATCH 28/28] delete outdated comment add CHANGELOG

---
 CHANGELOG.md           | 1 +
 src/PostgREST/Admin.hs | 2 --
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ac956f5329..8c9321a80b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
  - #3019, Transaction-Scoped Settings are now shown clearly in the Postgres logs - @laurenceisla
    + Shows `set_config('pgrst.setting_name', $1)` instead of `setconfig($1, $2)`
    + Does not apply to role settings and `app.settings.*`
+ - #2420, Fix bogus message when listening on port 0 - @develop7
 
 ### Changed
 
diff --git a/src/PostgREST/Admin.hs b/src/PostgREST/Admin.hs
index 64ef9372af..f7f8648e6c 100644
--- a/src/PostgREST/Admin.hs
+++ b/src/PostgREST/Admin.hs
@@ -50,8 +50,6 @@ admin appState appConfig req respond  = do
 
 -- Try to connect to the main app socket
 -- Note that it doesn't even send a valid HTTP request, we just want to check that the main app is accepting connections
--- The code for resolving the "*4", "!4", "*6", "!6", "*" special values is taken from
--- https://hackage.haskell.org/package/streaming-commons-0.2.2.4/docs/src/Data.Streaming.Network.html#bindPortGenEx
 reachMainApp :: Socket -> IO (Either IOException ())
 reachMainApp appSock = do
   sockAddr <- getSocketName appSock