feat: add timezone to Prefer header

CHANGELOG.md

@@ -15,7 +15,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
  - #2983, Add more data to `Server-Timing` header - @develop7
  - #2441, Add config `server-cors-allowed-origins` to specify CORS origins - @taimoorzaeem
  - #2825, SQL handlers for custom media types - @steve-chavez
-  - Solves #1548, #2699, #2763, #2170, #1462, #1102, #1374, #2901
+   + Solves #1548, #2699, #2763, #2170, #1462, #1102, #1374, #2901
+ - #2799, Add timezone in Prefer header - @taimoorzaeem
 
 ### Fixed
 

nix/tools/withTools.nix

@@ -72,7 +72,7 @@ let
         # We try to make the database cluster as independent as possible from the host
         # by specifying the timezone, locale and encoding.
         # initdb -U creates a superuser(man initdb)
-        PGTZ=UTC initdb --no-locale --encoding=UTF8 --nosync -U "${superuserRole}" --auth=trust \
+        TZ=$PGTZ initdb --no-locale --encoding=UTF8 --nosync -U "${superuserRole}" --auth=trust \
           >> "$setuplog"
 
         log "Starting the database cluster..."

src/PostgREST/ApiRequest/Preferences.hs

@@ -10,12 +10,12 @@
 module PostgREST.ApiRequest.Preferences
   ( Preferences(..)
   , PreferCount(..)
+  , PreferHandling(..)
   , PreferMissing(..)
   , PreferParameters(..)
   , PreferRepresentation(..)
   , PreferResolution(..)
   , PreferTransaction(..)
-  , PreferHandling(..)
   , fromHeaders
   , shouldCount
   , prefAppliedHeader
@@ -49,6 +49,7 @@ data Preferences
     , preferTransaction    :: Maybe PreferTransaction
     , preferMissing        :: Maybe PreferMissing
     , preferHandling       :: Maybe PreferHandling
+    , preferTimezone       :: Maybe ByteString
     , invalidPrefs         :: [ByteString]
     }
 
@@ -57,7 +58,7 @@ data Preferences
 --
 -- One header with comma-separated values can be used to set multiple preferences:
 --
--- >>> pPrint $ fromHeaders True [("Prefer", "resolution=ignore-duplicates, count=exact")]
+-- >>> pPrint $ fromHeaders True [("Prefer", "resolution=ignore-duplicates, count=exact, timezone=America/Los_Angeles")]
 -- Preferences
 --     { preferResolution = Just IgnoreDuplicates
 --     , preferRepresentation = Nothing
@@ -66,6 +67,7 @@ data Preferences
 --     , preferTransaction = Nothing
 --     , preferMissing = Nothing
 --     , preferHandling = Nothing
+--     , preferTimezone = Just "America/Los_Angeles"
 --     , invalidPrefs = []
 --     }
 --
@@ -80,6 +82,7 @@ data Preferences
 --     , preferTransaction = Nothing
 --     , preferMissing = Just ApplyNulls
 --     , preferHandling = Just Lenient
+--     , preferTimezone = Nothing
 --     , invalidPrefs = [ "invalid" ]
 --     }
 --
@@ -110,6 +113,7 @@ data Preferences
 --     , preferTransaction = Just Commit
 --     , preferMissing = Just ApplyDefaults
 --     , preferHandling = Just Strict
+--     , preferTimezone = Nothing
 --     , invalidPrefs = [ "anything" ]
 --     }
 --
@@ -123,7 +127,8 @@ fromHeaders allowTxEndOverride headers =
     , preferTransaction    = if allowTxEndOverride then parsePrefs [Commit, Rollback] else Nothing
     , preferMissing        = parsePrefs [ApplyDefaults, ApplyNulls]
     , preferHandling       = parsePrefs [Strict, Lenient]
-    , invalidPrefs         = filter (`notElem` acceptedPrefs) prefs
+    , preferTimezone       = listToMaybe timezonePref -- In "timezone=America/Los_Angeles", drop timezone= and get "America/Los_Angeles"
+    , invalidPrefs         = filter ((/= "timezone=") . BS.take 9) $ filter (`notElem` acceptedPrefs) prefs
     }
   where
     mapToHeadVal :: ToHeaderValue a => [a] -> [ByteString]
@@ -138,6 +143,7 @@ fromHeaders allowTxEndOverride headers =
 
     prefHeaders = filter ((==) HTTP.hPrefer . fst) headers
     prefs = fmap BS.strip . concatMap (BS.split ',' . snd) $ prefHeaders
+    timezonePref = [ BS.drop 9 p | p <- prefs, BS.take 9 p == "timezone="]
 
     parsePrefs :: ToHeaderValue a => [a] -> Maybe a
     parsePrefs vals =

src/PostgREST/AppState.hs

@@ -57,7 +57,8 @@ import PostgREST.Config                  (AppConfig (..),
                                           readAppConfig)
 import PostgREST.Config.Database         (queryDbSettings,
                                           queryPgVersion,
-                                          queryRoleSettings)
+                                          queryRoleSettings,
+                                          queryTimezones)
 import PostgREST.Config.PgVersion        (PgVersion (..),
                                           minimumPgVersion)
 import PostgREST.SchemaCache             (SchemaCache,
@@ -405,7 +406,18 @@ reReadConfig startingUp appState = do
         Right x -> pure x
     else
       pure mempty
-  readAppConfig dbSettings configFilePath (Just configDbUri) roleSettings roleIsolationLvl >>= \case
+  timezoneNames <-
+    if configDbConfig then do
+      names <- usePool appState $ queryTimezones configDbPreparedStatements
+      case names of
+        Left e -> do
+          logWithZTime appState "An error ocurred when trying to query the timezones"
+          logPgrstError appState e
+          pure mempty
+        Right x -> pure x
+    else
+      pure mempty
+  readAppConfig dbSettings configFilePath (Just configDbUri) roleSettings roleIsolationLvl timezoneNames >>= \case
     Left err   ->
       if startingUp then
         panic err -- die on invalid config if the program is starting up

src/PostgREST/CLI.hs

@@ -32,7 +32,7 @@ import Protolude hiding (hPutStrLn)
 main :: App.SignalHandlerInstaller -> Maybe App.SocketRunner -> CLI -> IO ()
 main installSignalHandlers runAppWithSocket CLI{cliCommand, cliPath} = do
   conf@AppConfig{..} <-
-    either panic identity <$> Config.readAppConfig mempty cliPath Nothing mempty mempty
+    either panic identity <$> Config.readAppConfig mempty cliPath Nothing mempty mempty mempty
 
   -- Per https://github.com/PostgREST/postgrest/issues/268, we want to
   -- explicitly close the connections to PostgreSQL on shutdown.

src/PostgREST/Config.hs

@@ -56,7 +56,7 @@ import System.Environment      (getEnvironment)
 import System.Posix.Types      (FileMode)
 
 import PostgREST.Config.Database         (RoleIsolationLvl,
-                                          RoleSettings)
+                                          RoleSettings, TimezoneNames)
 import PostgREST.Config.JSPath           (JSPath, JSPathExp (..),
                                           dumpJSPath, pRoleClaimKey)
 import PostgREST.Config.Proxy            (Proxy (..),
@@ -110,6 +110,7 @@ data AppConfig = AppConfig
   , configAdminServerPort          :: Maybe Int
   , configRoleSettings             :: RoleSettings
   , configRoleIsoLvl               :: RoleIsolationLvl
+  , configTimezoneNames            :: TimezoneNames
   , configInternalSCSleep          :: Maybe Int32
   }
 
@@ -207,13 +208,13 @@ instance JustIfMaybe a (Maybe a) where
 
 -- | Reads and parses the config and overrides its parameters from env vars,
 -- files or db settings.
-readAppConfig :: [(Text, Text)] -> Maybe FilePath -> Maybe Text -> RoleSettings -> RoleIsolationLvl -> IO (Either Text AppConfig)
-readAppConfig dbSettings optPath prevDbUri roleSettings roleIsolationLvl = do
+readAppConfig :: [(Text, Text)] -> Maybe FilePath -> Maybe Text -> RoleSettings -> RoleIsolationLvl -> TimezoneNames -> IO (Either Text AppConfig)
+readAppConfig dbSettings optPath prevDbUri roleSettings roleIsolationLvl timezoneNames = do
   env <- readPGRSTEnvironment
   -- if no filename provided, start with an empty map to read config from environment
   conf <- maybe (return $ Right M.empty) loadConfig optPath
 
-  case C.runParser (parser optPath env dbSettings roleSettings roleIsolationLvl) =<< mapLeft show conf of
+  case C.runParser (parser optPath env dbSettings roleSettings roleIsolationLvl timezoneNames) =<< mapLeft show conf of
     Left err ->
       return . Left $ "Error in config " <> err
     Right parsedConfig ->
@@ -228,8 +229,8 @@ readAppConfig dbSettings optPath prevDbUri roleSettings roleIsolationLvl = do
       decodeJWKS <$>
         (decodeSecret =<< readSecretFile =<< readDbUriFile prevDbUri parsedConfig)
 
-parser :: Maybe FilePath -> Environment -> [(Text, Text)] -> RoleSettings -> RoleIsolationLvl -> C.Parser C.Config AppConfig
-parser optPath env dbSettings roleSettings roleIsolationLvl =
+parser :: Maybe FilePath -> Environment -> [(Text, Text)] -> RoleSettings -> RoleIsolationLvl -> TimezoneNames -> C.Parser C.Config AppConfig
+parser optPath env dbSettings roleSettings roleIsolationLvl timezoneNames =
   AppConfig
     <$> parseAppSettings "app.settings"
     <*> (fmap encodeUtf8 <$> optString "db-anon-role")
@@ -280,6 +281,7 @@ parser optPath env dbSettings roleSettings roleIsolationLvl =
     <*> optInt "admin-server-port"
     <*> pure roleSettings
     <*> pure roleIsolationLvl
+    <*> pure timezoneNames
     <*> optInt "internal-schema-cache-sleep"
   where
     parseAppSettings :: C.Key -> C.Parser C.Config [(Text, Text)]

src/PostgREST/Config/Database.hs

@@ -3,10 +3,12 @@
 module PostgREST.Config.Database
   ( pgVersionStatement
   , queryDbSettings
-  , queryRoleSettings
   , queryPgVersion
+  , queryRoleSettings
+  , queryTimezones
   , RoleSettings
   , RoleIsolationLvl
+  , TimezoneNames
   , toIsolationLevel
   ) where
 
@@ -29,6 +31,7 @@ import Protolude
 
 type RoleSettings     = (HM.HashMap ByteString (HM.HashMap ByteString ByteString))
 type RoleIsolationLvl = HM.HashMap ByteString SQL.IsolationLevel
+type TimezoneNames    = [Text] -- cache timezone names for prefer timezone=
 
 toIsolationLevel :: (Eq a, IsString a) => a -> SQL.IsolationLevel
 toIsolationLevel a = case a of
@@ -174,6 +177,15 @@ queryRoleSettings prepared =
     rows :: HD.Result [(Text, Maybe Text, [(Text, Text)])]
     rows = HD.rowList $ (,,) <$> column HD.text <*> nullableColumn HD.text <*> compositeArrayColumn ((,) <$> compositeField HD.text <*> compositeField HD.text)
 
+queryTimezones :: Bool -> Session TimezoneNames
+queryTimezones prepared =
+  let transaction = if prepared then SQL.transaction else SQL.unpreparedTransaction in
+  transaction SQL.ReadCommitted SQL.Read $ SQL.statement mempty $ SQL.Statement sql HE.noParams decodeTimezones prepared
+  where
+    sql = "SELECT name FROM pg_timezone_names"
+    decodeTimezones :: HD.Result [Text]
+    decodeTimezones = HD.rowList $ column HD.text
+
 column :: HD.Value a -> HD.Row a
 column = HD.column . HD.nonNullable
 

src/PostgREST/Query.hs

@@ -19,6 +19,7 @@ import qualified Data.Aeson.KeyMap                 as KM
 import qualified Data.ByteString                   as BS
 import qualified Data.ByteString.Lazy.Char8        as LBS
 import qualified Data.HashMap.Strict               as HM
+import qualified Data.List                         as L
 import qualified Data.Set                          as S
 import qualified Data.Text.Encoding                as T
 import qualified Hasql.Decoders                    as HD
@@ -239,29 +240,32 @@ optionalRollback AppConfig{..} ApiRequest{iPreferences=Preferences{..}} = do
 -- | Runs local (transaction scoped) GUCs for every request.
 setPgLocals :: AppConfig  -> KM.KeyMap JSON.Value -> BS.ByteString -> [(ByteString, ByteString)] ->
                ApiRequest -> PgVersion -> DbHandler ()
-setPgLocals AppConfig{..} claims role roleSettings req actualPgVersion = lift $
+setPgLocals AppConfig{..} claims role roleSettings ApiRequest{..} actualPgVersion = lift $
   SQL.statement mempty $ SQL.dynamicallyParameterized
-    ("select " <> intercalateSnippet ", " (searchPathSql : roleSql ++ roleSettingsSql ++ claimsSql ++ [methodSql, pathSql] ++ headersSql ++ cookiesSql ++ appSettingsSql))
+    ("select " <> intercalateSnippet ", " (searchPathSql : roleSql ++ roleSettingsSql ++ claimsSql ++ [methodSql, pathSql] ++ headersSql ++ cookiesSql ++ timezoneSql ++ appSettingsSql))
     HD.noResult configDbPreparedStatements
   where
-    methodSql = setConfigLocal mempty ("request.method", iMethod req)
-    pathSql = setConfigLocal mempty ("request.path", iPath req)
+    methodSql = setConfigLocal mempty ("request.method", iMethod)
+    pathSql = setConfigLocal mempty ("request.path", iPath)
     headersSql = if usesLegacyGucs
-                   then setConfigLocal "request.header." <$> iHeaders req
-                   else setConfigLocalJson "request.headers" (iHeaders req)
+                   then setConfigLocal "request.header." <$> iHeaders
+                   else setConfigLocalJson "request.headers" iHeaders
     cookiesSql = if usesLegacyGucs
-                   then setConfigLocal "request.cookie." <$> iCookies req
-                   else setConfigLocalJson "request.cookies" (iCookies req)
+                   then setConfigLocal "request.cookie." <$> iCookies
+                   else setConfigLocalJson "request.cookies" iCookies
     claimsSql = if usesLegacyGucs
                   then setConfigLocal "request.jwt.claim." <$> [(toUtf8 $ K.toText c, toUtf8 $ unquoted v) | (c,v) <- KM.toList claims]
                   else [setConfigLocal mempty ("request.jwt.claims", LBS.toStrict $ JSON.encode claims)]
     roleSql = [setConfigLocal mempty ("role", role)]
     roleSettingsSql = setConfigLocal mempty <$> roleSettings
     appSettingsSql = setConfigLocal mempty <$> (join bimap toUtf8 <$> configAppSettings)
     searchPathSql =
-      let schemas = escapeIdentList (iSchema req : configDbExtraSearchPath) in
+      let schemas = escapeIdentList (iSchema : configDbExtraSearchPath) in
       setConfigLocal mempty ("search_path", schemas)
     usesLegacyGucs = configDbUseLegacyGucs && actualPgVersion < pgVersion140
+    getTimezone tz = if isJust $ L.find (== T.decodeUtf8 tz) configTimezoneNames then [setConfigLocal mempty ("timezone", tz)] else mempty
+    timezoneSql = maybe mempty getTimezone $ preferTimezone iPreferences
+    -- remove '' from
 
     unquoted :: JSON.Value -> Text
     unquoted (JSON.String t) = t

src/PostgREST/Response.hs

@@ -74,7 +74,7 @@ readResponse WrappedReadPlan{wrMedia} headersOnly identifier ctxApiRequest@ApiRe
     RSStandard{..} -> do
       let
         (status, contentRange) = RangeQuery.rangeStatusHeader iTopLevelRange rsQueryTotal rsTableTotal
-        prefHeader = maybeToList . prefAppliedHeader $ Preferences Nothing Nothing Nothing preferCount preferTransaction Nothing preferHandling []
+        prefHeader = maybeToList . prefAppliedHeader $ Preferences Nothing Nothing Nothing preferCount preferTransaction Nothing preferHandling Nothing []
         headers =
           [ contentRange
           , ( "Content-Location"
@@ -105,7 +105,7 @@ createResponse QualifiedIdentifier{..} MutateReadPlan{mrMutatePlan, mrMedia} ctx
       pkCols = case mrMutatePlan of { Insert{insPkCols} -> insPkCols; _ -> mempty;}
       prefHeader = prefAppliedHeader $
         Preferences (if null pkCols && isNothing (qsOnConflict iQueryParams) then Nothing else preferResolution)
-        preferRepresentation Nothing preferCount preferTransaction preferMissing preferHandling []
+        preferRepresentation Nothing preferCount preferTransaction preferMissing preferHandling Nothing []
       headers =
         catMaybes
           [ if null rsLocation then
@@ -146,7 +146,7 @@ updateResponse MutateReadPlan{mrMedia} ctxApiRequest@ApiRequest{iPreferences=Pre
       contentRangeHeader =
         Just . RangeQuery.contentRangeH 0 (rsQueryTotal - 1) $
           if shouldCount preferCount then Just rsQueryTotal else Nothing
-      prefHeader = prefAppliedHeader $ Preferences Nothing preferRepresentation Nothing preferCount preferTransaction preferMissing preferHandling []
+      prefHeader = prefAppliedHeader $ Preferences Nothing preferRepresentation Nothing preferCount preferTransaction preferMissing preferHandling Nothing []
       headers = catMaybes [contentRangeHeader, prefHeader]
 
     let (status, headers', body) =
@@ -166,7 +166,7 @@ singleUpsertResponse :: MutateReadPlan -> ApiRequest -> ResultSet -> Either Erro
 singleUpsertResponse MutateReadPlan{mrMedia} ctxApiRequest@ApiRequest{iPreferences=Preferences{..}} resultSet = case resultSet of
   RSStandard {..} -> do
     let
-      prefHeader = maybeToList . prefAppliedHeader $ Preferences Nothing preferRepresentation Nothing preferCount preferTransaction Nothing preferHandling []
+      prefHeader = maybeToList . prefAppliedHeader $ Preferences Nothing preferRepresentation Nothing preferCount preferTransaction Nothing preferHandling Nothing []
       cTHeader = contentTypeHeaders mrMedia ctxApiRequest
 
     let isInsertIfGTZero i = if i > 0 then HTTP.status201 else HTTP.status200
@@ -190,7 +190,7 @@ deleteResponse MutateReadPlan{mrMedia} ctxApiRequest@ApiRequest{iPreferences=Pre
       contentRangeHeader =
         RangeQuery.contentRangeH 1 0 $
           if shouldCount preferCount then Just rsQueryTotal else Nothing
-      prefHeader = maybeToList . prefAppliedHeader $ Preferences Nothing preferRepresentation Nothing preferCount preferTransaction Nothing preferHandling []
+      prefHeader = maybeToList . prefAppliedHeader $ Preferences Nothing preferRepresentation Nothing preferCount preferTransaction Nothing preferHandling Nothing []
       headers = contentRangeHeader : prefHeader
 
     let (status, headers', body) =
@@ -243,7 +243,7 @@ invokeResponse CallReadPlan{crMedia} invMethod proc ctxApiRequest@ApiRequest{iPr
         then Error.errorPayload $ Error.ApiRequestError $ ApiRequestTypes.InvalidRange
           $ ApiRequestTypes.OutOfBounds (show $ RangeQuery.rangeOffset iTopLevelRange) (maybe "0" show rsTableTotal)
         else LBS.fromStrict rsBody
-      prefHeader = maybeToList . prefAppliedHeader $ Preferences Nothing Nothing preferParameters preferCount preferTransaction Nothing preferHandling []
+      prefHeader = maybeToList . prefAppliedHeader $ Preferences Nothing Nothing preferParameters preferCount preferTransaction Nothing preferHandling Nothing []
       headers = contentRange : prefHeader
 
     let (status', headers', body) =

test/io/fixtures.sql

@@ -178,3 +178,13 @@ $$;
 create function terminate_pgrst() returns setof record as $$
 select pg_terminate_backend(pid) from pg_stat_activity where application_name iLIKE '%postgrest%';
 $$ language sql security definer;
+
+create table timezone_values (
+  t timestamp with time zone
+);
+grant all on timezone_values to postgrest_test_anonymous;
+
+truncate table timezone_values cascade;
+insert into timezone_values values ('2023-10-18 12:37:59.611000+0000');
+insert into timezone_values values ('2023-10-18 14:37:59.611000+0000');
+insert into timezone_values values ('2023-10-18 16:37:59.611000+0000');

test/io/test_io.py

@@ -1294,3 +1294,33 @@ def test_no_preflight_request_with_CORS_config_should_not_return_header(defaulte
     with run(env=env) as postgrest:
         response = postgrest.session.get("/items", headers=headers)
         assert "Access-Control-Allow-Origin" not in response.headers
+
+
+def test_prefer_timezone(defaultenv):
+    "timezone=America/Los_Angeles should change timezone successfully"
+
+    env = {**defaultenv, "PGRST_DB_CONFIG": "true", "PGRST_JWT_SECRET": SECRET}
+
+    headers = {
+        "Prefer": "handling=strict, timezone=America/Los_Angeles",
+    }
+
+    with run(env=env) as postgrest:
+        response = postgrest.session.get("/timezone_values", headers=headers)
+        response_body = '[{"t":"2023-10-18T05:37:59.611-07:00"}, \n {"t":"2023-10-18T07:37:59.611-07:00"}, \n {"t":"2023-10-18T09:37:59.611-07:00"}]'
+        assert response.text == response_body
+
+
+def test_prefer_timezone_with_invalid_timezone(defaultenv):
+    "timezone=Invalid/XXX should set time to default timezone"
+
+    env = {**defaultenv, "PGRST_DB_CONFIG": "true", "PGRST_JWT_SECRET": SECRET}
+
+    headers = {
+        "Prefer": "handling=strict, timezone=Invalid/XXX",
+    }
+
+    with run(env=env) as postgrest:
+        response = postgrest.session.get("/timezone_values", headers=headers)
+        response_body = '[{"t":"2023-10-18T12:37:59.611+00:00"}, \n {"t":"2023-10-18T14:37:59.611+00:00"}, \n {"t":"2023-10-18T16:37:59.611+00:00"}]'
+        assert response.text == response_body

test/spec/SpecHelper.hs

@@ -139,6 +139,7 @@ baseCfg = let secret = Just $ encodeUtf8 "reallyreallyreallyreallyverysafe" in
   , configAdminServerPort           = Nothing
   , configRoleSettings              = mempty
   , configRoleIsoLvl                = mempty
+  , configTimezoneNames             = mempty
   , configInternalSCSleep           = Nothing
   }