refactor: Simplify App.initServerSocket

This change gets rid of unnecessary explicit bindRandomPortTCP in initServerSocket. Returned port value was ignored in removed code anyway as assigned port retrieval from an open socket is handled elsewhere.

src/PostgREST/App.hs

@@ -63,8 +63,7 @@ import PostgREST.Version              (docsVersion, prettyVersion)
 
 import qualified Data.ByteString.Char8     as BS
 import qualified Data.List                 as L
-import           Data.Streaming.Network    (bindPortTCP,
-                                            bindRandomPortTCP)
+import           Data.Streaming.Network    (bindPortTCP)
 import qualified Data.Text                 as T
 import qualified Network.HTTP.Types        as HTTP
 import qualified Network.HTTP.Types.Header as HTTP (hVary)
@@ -262,33 +261,15 @@ type AppSockets = (NS.Socket, Maybe NS.Socket)
 
 initSockets :: AppConfig -> IO AppSockets
 initSockets AppConfig{..} = do
-  let
-    cfg'usp = configServerUnixSocket
-    cfg'uspm = configServerUnixSocketMode
-    cfg'host = configServerHost
-    cfg'port = configServerPort
-    cfg'adminHost = configAdminServerHost
-    cfg'adminPort = configAdminServerPort
-
-  sock <- case cfg'usp of
+  sock <- case configServerUnixSocket of
     -- 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
-          then 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
+    Just path -> createAndBindDomainSocket path configServerUnixSocketMode
+    Nothing -> bindPortTCP configServerPort (fromString $ T.unpack configServerHost)
 
-  adminSock <- case cfg'adminPort of
+  adminSock <- case configAdminServerPort of
     Just adminPort -> do
-      adminSock <- bindPortTCP adminPort (fromString $ T.unpack cfg'adminHost)
+      adminSock <- bindPortTCP adminPort (fromString $ T.unpack configAdminServerHost)
       pure $ Just adminSock
     Nothing -> pure Nothing