add config option server-unix-socket-mode (#1415)

* added config option server-unix-socket-mode to enable custom socket permissions

* added server-unix-socket-mode input validation

CHANGELOG.md

@@ -7,6 +7,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
+- #1415, Add support for user defined socket permission via `server-unix-socket-mode` config option - @Dansvidania
 - #1383, Add support for HEAD request - @steve-chavez
 - #1378, Add support for `Prefer: count=planned` and `Prefer: count=estimated` on GET /table - @steve-chavez
 

main/Main.hs

@@ -12,6 +12,7 @@ import Control.AutoUpdate       (defaultUpdateSettings, mkAutoUpdate,
 import Control.Retry            (RetryStatus, capDelay,
                                  exponentialBackoff, retrying,
                                  rsPreviousDelay)
+import Data.Either.Combinators  (whenLeft)
 import Data.IORef               (IORef, atomicWriteIORef, newIORef,
                                  readIORef)
 import Data.String              (IsString (..))
@@ -31,6 +32,8 @@ import Network.Wai.Handler.Warp (defaultSettings, runSettings,
 import System.Directory         (removeFile)
 import System.IO                (BufferMode (..), hSetBuffering)
 import System.IO.Error          (isDoesNotExistError)
+import System.Posix.Files       (setFileMode)
+import System.Posix.Types       (FileMode)
 
 import PostgREST.App         (postgrest)
 import PostgREST.Config      (AppConfig (..), configPoolTimeout',
@@ -163,6 +166,7 @@ main = do
       port = configPort conf
       proxy = configProxyUri conf
       maybeSocketAddr = configSocket conf
+      socketFileMode = configSocketMode conf
       pgSettings = toS (configDatabase conf) -- is the db-uri
       roleClaimKey = configRoleClaimKey conf
       appSettings =
@@ -171,13 +175,15 @@ main = do
         . setServerName (toS $ "postgrest/" <> prettyVersion) $
         defaultSettings
 
+  whenLeft socketFileMode panic
+
   -- Checks that the provided proxy uri is formated correctly
   when (isMalformedProxyUri $ toS <$> proxy) $
     panic
       "Malformed proxy uri, a correct example: https://example.com:8443/basePath"
 
   -- Checks that the provided jspath is valid
-  when (isLeft roleClaimKey) $
+  whenLeft roleClaimKey $
     panic $ show roleClaimKey
 
   --
@@ -250,7 +256,7 @@ main = do
              runSettings appSettings postgrestApplication
          Just socketAddr -> do
              -- run postgrest application with user defined socket
-             sock <- createAndBindSocket (unpack socketAddr)
+             sock <- createAndBindSocket (unpack socketAddr) (rightToMaybe socketFileMode)
              listen sock maxListenQueue
              putStrLn $ ("Listening on unix socket " :: Text) <> show socketAddr
              runSettingsSocket appSettings sock postgrestApplication
@@ -324,11 +330,12 @@ loadDbUriFile conf = extractDbUri mDbUri
         Just filename -> strip <$> readFile (toS filename)
     setDbUri dbUri = conf {configDatabase = dbUri}
 
-createAndBindSocket :: FilePath -> IO Socket
-createAndBindSocket filePath = do
-  deleteSocketFileIfExist filePath
+createAndBindSocket :: FilePath -> Maybe FileMode -> IO Socket
+createAndBindSocket socketFilePath maybeSocketFileMode = do
+  deleteSocketFileIfExist socketFilePath
   sock <- socket AF_UNIX Stream defaultProtocol
-  bind sock $ SockAddrUnix filePath
+  bind sock $ SockAddrUnix socketFilePath
+  mapM_ (setFileMode socketFilePath) maybeSocketFileMode
   return sock
   where
     deleteSocketFileIfExist path = removeFile path `catch` handleDoesNotExist

postgrest.cabal

@@ -97,6 +97,7 @@ executable postgrest
                     , base64-bytestring >= 1 && < 1.1
                     , bytestring        >= 0.10.8 && < 0.11
                     , directory         >= 1.2.6 && < 1.4
+                    , either            >= 4.4.1 && < 5.1
                     , hasql             >= 1.4 && < 1.5
                     , hasql-pool        >= 0.5 && < 0.6
                     , hasql-transaction >= 0.7.2 && < 0.8

src/PostgREST/Config.hs

@@ -46,8 +46,10 @@ import Data.Text.IO                (hPutStrLn)
 import Data.Version                (versionBranch)
 import Development.GitRev          (gitHash)
 import Network.Wai.Middleware.Cors (CorsResourcePolicy (..))
+import Numeric                     (readOct)
 import Paths_postgrest             (version)
 import System.IO.Error             (IOError)
+import System.Posix.Types          (FileMode)
 
 import Control.Applicative
 import Data.Monoid
@@ -63,6 +65,7 @@ import Protolude         hiding (concat, hPutStrLn, intercalate, null,
                           take, (<>))
 
 
+
 -- | Config file settings for the server
 data AppConfig = AppConfig {
     configDatabase          :: Text
@@ -72,6 +75,7 @@ data AppConfig = AppConfig {
   , configHost              :: Text
   , configPort              :: Int
   , configSocket            :: Maybe Text
+  , configSocketMode        :: Either Text FileMode
 
   , configJwtSecret         :: Maybe B.ByteString
   , configJwtSecretIsBase64 :: Bool
@@ -155,6 +159,7 @@ readOptions = do
         <*> (fromMaybe "!4" <$> optString "server-host")
         <*> (fromMaybe 3000 <$> optInt "server-port")
         <*> optString "server-unix-socket"
+        <*> parseSocketFileMode "server-unix-socket-mode"
         <*> (fmap encodeUtf8 <$> optString "jwt-secret")
         <*> (fromMaybe False <$> optBool "secret-is-base64")
         <*> parseJwtAudience "jwt-aud"
@@ -169,6 +174,19 @@ readOptions = do
         <*> optString "root-spec"
         <*> (maybe [] (fmap encodeUtf8 . splitOnCommas) <$> optValue "raw-media-types")
 
+    parseSocketFileMode :: C.Key -> C.Parser C.Config (Either Text FileMode)
+    parseSocketFileMode k =
+      C.optional k C.string >>= \case
+        Nothing -> pure $ Right 493 -- return default 755 mode if no value was provided
+        Just fileModeText ->
+          case (readOct . unpack) fileModeText of
+            []              ->
+              pure $ Left "Invalid server-unix-socket-mode: not an octal"
+            (fileMode, _):_ ->
+              if fileMode < 384 || fileMode > 511
+                then pure $ Left "Invalid server-unix-socket-mode: needs to be between 600 and 777"
+                else pure $ Right fileMode
+
     parseJwtAudience :: C.Key -> C.Parser C.Config (Maybe StringOrURI)
     parseJwtAudience k =
       C.optional k C.string >>= \case
@@ -248,6 +266,9 @@ readOptions = do
           |## unix socket location
           |## if specified it takes precedence over server-port
           |# server-unix-socket = "/tmp/pgrst.sock"
+          |## unix socket file mode
+          |## when none is provided, 755 is applied by default
+          |# server-unix-socket-mode = "755"
           |
           |## base url for swagger output
           |# server-proxy-uri = ""

test/SpecHelper.hs

@@ -66,6 +66,8 @@ _baseCfg =  -- Connection Settings
   AppConfig mempty "postgrest_test_anonymous" Nothing "test" "localhost" 3000
             -- No user configured Unix Socket
             Nothing
+            -- No user configured Unix Socket file mode (defaults to 755)
+            (Right 493)
             -- Jwt settings
             (Just $ encodeUtf8 "reallyreallyreallyreallyverysafe") False Nothing
             -- Connection Modifiers