add: make config log-level reloadable

Closes #5113.

Signed-off-by: Taimoor Zaeem <taimoorzaeem@gmail.com>

test/io/configs/sigusr2-settings.config

@@ -3,3 +3,6 @@ db-schemas = "public"
 
 app.settings.name_var = "John"
 jwt-secret = "invalidinvalidinvalidinvalidinvalid"
+
+# will be replaced in test
+log-level = "error"

test/io/test_io.py

@@ -1931,3 +1931,40 @@ def test_use_legacy_target_names(enabled, defaultenv):
         else:
             assert response.status_code == 400
             assert not has_warning_log and not has_hint_log
+
+
+def test_config_log_level_is_reloadable(tmp_path, defaultenv):
+    "Config log-level should be reloadable on SIGUSR2"
+
+    config = (CONFIGSDIR / "sigusr2-settings.config").read_text()
+    configfile = tmp_path / "test.config"
+    configfile.write_text(config)
+
+    # Delete the env variable for "log-level" so the config file value isn't overridden
+    del defaultenv["PGRST_LOG_LEVEL"]
+
+    with run(configfile, env=defaultenv) as postgrest:
+        response = postgrest.session.get("/projects")
+        assert response.status_code == 200
+        output = postgrest.read_stdout(nlines=5)
+
+        # log-level = error, so this log line shouldn't be logged
+        assert not any(
+            "Trying to borrow a connection from pool" in line for line in output
+        )
+
+        # change setting
+        configfile.write_text(
+            config.replace('log-level = "error"', 'log-level = "debug"')
+        )
+        # reload
+        postgrest.process.send_signal(signal.SIGUSR2)
+
+        sleep_until_postgrest_config_reload()
+
+        response = postgrest.session.get("/projects")
+        assert response.status_code == 200
+        output = postgrest.read_stdout(nlines=5)
+
+        # log-level = debug now, so this log line must be logged
+        assert any("Trying to borrow a connection from pool" in line for line in output)

test/observability/Main.hs

@@ -5,6 +5,7 @@ import qualified Hasql.Pool.Config          as P
 import qualified Hasql.Transaction.Sessions as HT
 
 import Data.Function (id)
+import Data.IORef    (newIORef, readIORef)
 
 import           PostgREST.App             (postgrest)
 import qualified PostgREST.AppState        as AppState
@@ -48,14 +49,15 @@ main = do
 
   -- cached schema cache so most tests run fast
   baseSchemaCache <- loadSCache pool testCfg
-  loggerState <- Logger.init
 
   let
     initApp sCache config = do
       -- duplicate poolChan as a starting point
+      confRef <- newIORef config
+      loggerState <- Logger.init (configLogLevel <$> readIORef confRef)
       obsChan <- dupChan poolChan
       stateObsChan <- newObsChan obsChan
-      appState <- AppState.initWithPool pool config loggerState metricsState (Metrics.observationMetrics metricsState <> writeChan obsChan) mempty
+      appState <- AppState.initWithPool pool confRef loggerState metricsState (Metrics.observationMetrics metricsState <> writeChan obsChan) mempty
       AppState.putPgVersion appState actualPgVersion
       AppState.putSchemaCache appState (Just sCache)
       return (SpecState appState metricsState stateObsChan, postgrest appState (pure ()))

test/spec/Main.hs

@@ -5,6 +5,7 @@ import qualified Hasql.Pool.Config          as P
 import qualified Hasql.Transaction.Sessions as HT
 
 import Data.Function (id)
+import Data.IORef    (newIORef, readIORef)
 
 import Test.Hspec
 
@@ -88,12 +89,13 @@ main = do
 
   -- cached schema cache so most tests run fast
   baseSchemaCache <- loadSCache pool baseCfg
-  loggerState <- Logger.init
   metricsState <- Metrics.init (configDbPoolSize baseCfg)
 
   let
     initApp sCache config = do
-      appState <- AppState.initWithPool pool config loggerState metricsState (Metrics.observationMetrics metricsState) mempty
+      confRef <- newIORef config
+      loggerState <- Logger.init (configLogLevel <$> readIORef confRef)
+      appState <- AppState.initWithPool pool confRef loggerState metricsState (Metrics.observationMetrics metricsState) mempty
       AppState.putPgVersion appState actualPgVersion
       AppState.putSchemaCache appState (Just sCache)
       return ((), postgrest appState (pure ()))