feat: Make GUC names for headers, cookies and jwt claims compatible with PostgreSQL v14

Getting the value for a header GUC on PostgreSQL v14 is done using `current_setting('request.headers')::json->>'name-of-header'` and in a similar way for `request.cookies` and `request.jwt.claims` PostgreSQL versions below 14 can opt in to the new JSON GUCs by setting the `db-use-legacy-gucs` config option to false (true by default)
2021-10-12 12:58:52 -05:00
parent ee56dd5db1
commit 627c3c34b7
27 changed files with 250 additions and 34 deletions
@@ -198,7 +198,7 @@ postgrestResponse conf maybeDbStructure jsonDbS pgVer pool time req = do

  runDbHandler pool (txMode apiRequest) jwtClaims (configDbPreparedStatements conf) .
    Middleware.optionalRollback conf apiRequest $
-      Middleware.runPgLocals conf jwtClaims handleReq apiRequest jsonDbS
+      Middleware.runPgLocals conf jwtClaims handleReq apiRequest jsonDbS pgVer

 runDbHandler :: SQL.Pool -> SQL.Mode -> Auth.JWTClaims -> Bool -> DbHandler a -> Handler IO a
 runDbHandler pool mode jwtClaims prepared handler = do
@@ -166,6 +166,10 @@ exampleConfigFile =
      |## Enable in-database configuration
      |db-config = true
      |
+      |## Determine if GUC request settings for headers, cookies and jwt claims use the legacy names (string with dashes, invalid starting from PostgreSQL v14) with text values instead of the new names (string without dashes, valid on all PostgreSQL versions) with json values.
+      |## For PostgreSQL v14 and up, this setting will be ignored.
+      |db-use-legacy-gucs = true
+      |
      |## how to terminate database transactions
      |## possible values are:
      |## commit (default)
@@ -81,6 +81,7 @@ data AppConfig = AppConfig
  , configDbTxRollbackAll       :: Bool
  , configDbUri                 :: Text
  , configDbEmbedDefaultJoin    :: JoinType
+  , configDbUseLegacyGucs       :: Bool
  , configFilePath              :: Maybe FilePath
  , configJWKS                  :: Maybe JWKSet
  , configJwtAudience           :: Maybe StringOrURI
@@ -135,6 +136,7 @@ toText conf =
      ,("db-tx-end",                 q . showTxEnd)
      ,("db-uri",                    q . configDbUri)
      ,("db-embed-default-join",     q . show . configDbEmbedDefaultJoin)
+      ,("db-use-legacy-gucs",            T.toLower . show . configDbUseLegacyGucs)
      ,("jwt-aud",                       toS . encode . maybe "" toJSON . configJwtAudience)
      ,("jwt-role-claim-key",        q . T.intercalate mempty . fmap show . configJwtRoleClaimKey)
      ,("jwt-secret",                q . toS . showJwtSecret)
@@ -226,6 +228,7 @@ parser optPath env dbSettings =
    <*> parseTxEnd "db-tx-end" fst
    <*> reqString "db-uri"
    <*> parseEmbedDefaultJoin "db-embed-default-join"
+    <*> (fromMaybe True <$> optBool "db-use-legacy-gucs")
    <*> pure optPath
    <*> pure Nothing
    <*> parseJwtAudience "jwt-aud"
@@ -12,6 +12,7 @@ module PostgREST.Config.PgVersion
  , pgVersion114
  , pgVersion121
  , pgVersion130
+  , pgVersion140
  ) where

 import qualified Data.Aeson as JSON
@@ -58,3 +59,6 @@ pgVersion121 = PgVersion 120001 "12.1"

 pgVersion130 :: PgVersion
 pgVersion130 = PgVersion 130000 "13.0"
+
+pgVersion140 :: PgVersion
+pgVersion140 = PgVersion 140000 "14.0"
@@ -14,6 +14,7 @@ module PostgREST.Middleware

 import qualified Data.Aeson                           as JSON
 import qualified Data.ByteString.Char8                as BS
+import qualified Data.ByteString.Lazy.Char8           as BSL
 import qualified Data.CaseInsensitive                 as CI
 import qualified Data.HashMap.Strict                  as M
 import qualified Data.Text                            as T
@@ -30,6 +31,8 @@ import qualified Network.Wai.Middleware.Gzip          as Wai
 import qualified Network.Wai.Middleware.RequestLogger as Wai
 import qualified Network.Wai.Middleware.Static        as Wai

+import Control.Arrow ((***))
+
 import Data.Function             (id)
 import Data.List                 (lookup)
 import Data.Scientific           (FPFormat (..), formatScientific,
@@ -40,6 +43,7 @@ import System.IO.Unsafe          (unsafePerformIO)
 import System.Log.FastLogger     (toLogStr)

 import PostgREST.Config             (AppConfig (..), LogLevel (..))
+import PostgREST.Config.PgVersion   (PgVersion (..), pgVersion140)
 import PostgREST.Error              (Error, errorResponseFor)
 import PostgREST.GucHeader          (addHeadersIfNotIncluded)
 import PostgREST.Query.SqlFragment  (fromQi, intercalateSnippet,
@@ -54,8 +58,8 @@ import Protolude.Conv (toS)
 -- | Runs local(transaction scoped) GUCs for every request, plus the pre-request function
 runPgLocals :: AppConfig   -> M.HashMap Text JSON.Value ->
               (ApiRequest -> ExceptT Error H.Transaction Wai.Response) ->
-               ApiRequest  -> ByteString -> ExceptT Error H.Transaction Wai.Response
-runPgLocals conf claims app req jsonDbS = do
+               ApiRequest  -> ByteString -> PgVersion -> ExceptT Error H.Transaction Wai.Response
+runPgLocals conf claims app req jsonDbS actualPgVersion = do
  lift $ H.statement mempty $ H.dynamicallyParameterized
    ("select " <> intercalateSnippet ", " (searchPathSql : roleSql ++ claimsSql ++ [methodSql, pathSql] ++ headersSql ++ cookiesSql ++ appSettingsSql ++ specSql))
    HD.noResult (configDbPreparedStatements conf)
@@ -64,12 +68,18 @@ runPgLocals conf claims app req jsonDbS = do
  where
    methodSql = setConfigLocal mempty ("request.method", iMethod req)
    pathSql = setConfigLocal mempty ("request.path", iPath req)
-    headersSql = setConfigLocal "request.header." <$> iHeaders req
-    cookiesSql = setConfigLocal "request.cookie." <$> iCookies req
+    headersSql = if usesLegacyGucs
+                   then setConfigLocal "request.header." <$> iHeaders req
+                   else setConfigLocalJson "request.headers" (iHeaders req)
+    cookiesSql = if usesLegacyGucs
+                   then setConfigLocal "request.cookie." <$> iCookies req
+                   else setConfigLocalJson "request.cookies" (iCookies req)
    claimsWithRole =
      let anon = JSON.String . toS $ configDbAnonRole conf in -- role claim defaults to anon if not specified in jwt
      M.union claims (M.singleton "role" anon)
-    claimsSql = setConfigLocal "request.jwt.claim." <$> [(toS c, toS $ unquoted v) | (c,v) <- M.toList claimsWithRole]
+    claimsSql = if usesLegacyGucs
+                  then setConfigLocal "request.jwt.claim." <$> [(toS c, toS $ unquoted v) | (c,v) <- M.toList claimsWithRole]
+                  else [setConfigLocal mempty ("request.jwt.claims", BSL.toStrict $ JSON.encode claimsWithRole)]
    roleSql = maybeToList $ (\x -> setConfigLocal mempty ("role", toS $ unquoted x)) <$> M.lookup "role" claimsWithRole
    appSettingsSql = setConfigLocal mempty <$> (join bimap toS <$> configAppSettings conf)
    searchPathSql =
@@ -79,10 +89,7 @@ runPgLocals conf claims app req jsonDbS = do
    specSql = case iTarget req of
      TargetProc{tpIsRootSpec=True} -> [setConfigLocal mempty ("request.spec", jsonDbS)]
      _                             -> mempty
-    -- | Do a pg set_config(setting, value, true) call. This is equivalent to a SET LOCAL.
-    setConfigLocal :: ByteString -> (ByteString, ByteString) -> H.Snippet
-    setConfigLocal prefix (k, v) =
-      "set_config(" <> unknownEncoder (prefix <> k) <> ", " <> unknownEncoder v <> ", true)"
+    usesLegacyGucs = configDbUseLegacyGucs conf && actualPgVersion < pgVersion140

 -- | Log in apache format. Only requests that have a status greater than minStatus are logged.
 -- | There's no way to filter logs in the apache format on wai-extra: https://hackage.haskell.org/package/wai-extra-3.0.29.2/docs/Network-Wai-Middleware-RequestLogger.html#t:OutputFormat.
@@ -181,3 +188,18 @@ optionalRollback AppConfig{..} ApiRequest{..} transaction = do
            [(HTTP.hPreferenceApplied, BS.pack (show Rollback))]
      | otherwise =
          identity
+
+-- | Do a pg set_config(setting, value, true) call. This is equivalent to a SET LOCAL.
+setConfigLocal :: ByteString -> (ByteString, ByteString) -> H.Snippet
+setConfigLocal prefix (k, v) =
+  "set_config(" <> unknownEncoder (prefix <> k) <> ", " <> unknownEncoder v <> ", true)"
+
+-- | Starting from PostgreSQL v14, some characters are not allowed for config names (mostly affecting headers with "-").
+-- | A JSON format string is used to avoid this problem. See https://github.com/PostgREST/postgrest/issues/1857
+setConfigLocalJson :: ByteString -> [(ByteString, ByteString)] -> [H.Snippet]
+setConfigLocalJson prefix keyVals = [setConfigLocal mempty (prefix, gucJsonVal keyVals)]
+  where
+    gucJsonVal :: [(ByteString, ByteString)] -> ByteString
+    gucJsonVal = BSL.toStrict . JSON.encode . M.fromList . arrayByteStringToText
+    arrayByteStringToText :: [(ByteString, ByteString)] -> [(Text,Text)]
+    arrayByteStringToText keyVal = (toS *** toS) <$> keyVal