fix: log db-schemas and db-extra-search-path in schema cache load error (#4108)

CHANGELOG.md

@@ -14,7 +14,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ### Fixed
 
 - Fix jwt error returning HTTP status `400` for invalid role by @taimoorzaeem in #3601
-- Allow `db-extra-search-path` to accept empty value by @taimoorzaeem in #4074
+- Fix `db-extra-search-path` cannot be set to nothing by @taimoorzaeem in #4074
+  + It can now be disabled by setting it to empty string.
+  + Schema Cache load error is now logged including `db-schemas` and `db-extra-search-path` config values.
 
 ## [13.0.0] - 2025-05-08
 

src/PostgREST/AppState.hs

@@ -407,7 +407,7 @@ retryingSchemaCacheLoad appState@AppState{stateObserver=observer, stateMainThrea
         Left e -> do
           putSCacheStatus appState SCPending
           putSchemaCache appState Nothing
-          observer $ SchemaCacheErrorObs e
+          observer $ SchemaCacheErrorObs configDbSchemas configDbExtraSearchPath e
           return Nothing
 
         Right sCache -> do

src/PostgREST/CLI.hs

@@ -60,7 +60,7 @@ dumpSchema appState = do
   case result of
     Left e -> do
       let observer = AppState.getObserver appState
-      observer $ SchemaCacheErrorObs e
+      observer $ SchemaCacheErrorObs configDbSchemas configDbExtraSearchPath e
       exitFailure
     Right sCache -> return $ JSON.encode sCache
 

src/PostgREST/Metrics.hs

@@ -52,7 +52,7 @@ observationMetrics (MetricsState poolTimeouts poolAvailable poolWaiting _ schema
   SchemaCacheLoadedObs resTime -> do
     withLabel schemaCacheLoads "SUCCESS" incCounter
     setGauge schemaCacheQueryTime resTime
-  SchemaCacheErrorObs _ -> do
+  SchemaCacheErrorObs{} -> do
     withLabel schemaCacheLoads "FAIL" incCounter
   _ ->
     pure ()

src/PostgREST/Observation.hs

@@ -14,6 +14,7 @@ module PostgREST.Observation
   ) where
 
 import qualified Data.ByteString.Lazy       as LBS
+import           Data.List.NonEmpty         (toList)
 import qualified Data.Text                  as T
 import qualified Data.Text.Encoding         as T
 import qualified Hasql.Connection           as SQL
@@ -25,7 +26,7 @@ import           Numeric                    (showFFloat)
 import           PostgREST.Config.PgVersion
 import qualified PostgREST.Error            as Error
 
-import Protolude
+import Protolude         hiding (toList)
 import Protolude.Partial (fromJust)
 
 data Observation
@@ -37,7 +38,7 @@ data Observation
   | ExitDBNoRecoveryObs
   | ExitDBFatalError ObsFatalError SQL.UsageError
   | DBConnectedObs Text
-  | SchemaCacheErrorObs SQL.UsageError
+  | SchemaCacheErrorObs (NonEmpty Text) [Text] SQL.UsageError
   | SchemaCacheQueriedObs Double
   | SchemaCacheSummaryObs Text
   | SchemaCacheLoadedObs Double
@@ -88,8 +89,12 @@ observationMessage = \case
     "If you are using connection poolers in transaction mode, try setting db-prepared-statements to false. " <> jsonMessage usageErr
   ExitDBFatalError ServerError08P01 usageErr ->
     "Connection poolers in statement mode are not supported." <> jsonMessage usageErr
-  SchemaCacheErrorObs usageErr ->
-    "Failed to load the schema cache. " <> jsonMessage usageErr
+  SchemaCacheErrorObs dbSchemas extraPaths usageErr ->
+    "Failed to load the schema cache using "
+      <> "db-schemas=" <> T.intercalate "," (toList dbSchemas)
+      <> " and "
+      <> "db-extra-search-path=" <> T.intercalate "," extraPaths
+      <> ". " <> jsonMessage usageErr
   SchemaCacheQueriedObs resultTime ->
     "Schema cache queried in " <> showMillis resultTime  <> " milliseconds"
   SchemaCacheSummaryObs summary ->

test/io/test_io.py

@@ -1909,3 +1909,23 @@ def test_allow_configs_to_be_set_to_empty(defaultenv):
     with run(env=env) as postgrest:
         response = postgrest.session.get("/projects")
         assert response.status_code == 200
+
+
+def test_schema_cache_error_observation(defaultenv):
+    "schema cache error observation should be logged with invalid db-schemas or db-extra-search-path"
+
+    env = {
+        **defaultenv,
+        "PGRST_DB_EXTRA_SEARCH_PATH": "x",
+    }
+
+    with run(env=env, no_startup_stdout=False, wait_for_readiness=False) as postgrest:
+        # TODO: postgrest should exit here, instead it keeps retrying
+        # exitCode = wait_until_exit(postgrest)
+        # assert exitCode == 1
+
+        output = postgrest.read_stdout(nlines=9)
+        assert (
+            "Failed to load the schema cache using db-schemas=public and db-extra-search-path=x"
+            in output[7]
+        )