Custom log eval error loop

CHANGELOG.md

@@ -13,6 +13,9 @@ Unreleased changes are available as `avenga/couper:edge` container.
   * Improved the way an SPA `bootstrap_file` gets cached and served in combination with `bootstrap_data` ([#656](https://github.com/avenga/couper/pull/656))
   * Harmonized and improved logged error information for references to undefined blocks ([#651](https://github.com/avenga/couper/pull/651))
 
+* **Fixed**
+  * Loop with evaluation error in [`custom_log_fields`](https://docs.couper.io/observation/logging#custom-logging) if log level is `"debug"` ([#659](https://github.com/avenga/couper/pull/659))
+
 ---
 
 ## [1.11.1](https://github.com/avenga/couper/releases/tag/v1.11.1)

logging/hooks/custom_logs.go

@@ -34,7 +34,13 @@ func init() {
 }
 
 func (c *CustomLogs) Levels() []logrus.Level {
-	return logrus.AllLevels
+	return []logrus.Level{
+		logrus.PanicLevel, // reasonable?
+		logrus.FatalLevel, // reasonable?
+		logrus.ErrorLevel,
+		logrus.WarnLevel, // not used?
+		logrus.InfoLevel,
+	}
 }
 
 func (c *CustomLogs) Fire(entry *logrus.Entry) error {

server/http_custom_logs_test.go

@@ -239,3 +239,18 @@ func TestCustomLogs_Merge(t *testing.T) {
 		t.Errorf("expected\n%#v\ngot\n%#v", exp, got)
 	}
 }
+
+func TestCustomLogs_EvalError(t *testing.T) {
+	client := newClient()
+	helper := test.New(t)
+
+	shutdown, hook := newCouper("testdata/integration/logs/04_couper.hcl", test.New(t))
+	defer shutdown()
+
+	req, err := http.NewRequest(http.MethodGet, "http://localhost:8080/", nil)
+	helper.Must(err)
+
+	hook.Reset()
+	_, err = client.Do(req)
+	helper.Must(err)
+}

server/http_integration_test.go

@@ -137,6 +137,7 @@ func newCouperWithConfig(couperConfig *config.Couper, helper *test.Helper) (func
 	defer testServerMu.Unlock()
 
 	log, hook := test.NewLogger()
+	log.Level, _ = logrus.ParseLevel(couperConfig.Settings.LogLevel)
 
 	ctx, cancelFn := context.WithCancel(context.Background())
 	shutdownFn := func() {

server/testdata/integration/logs/04_couper.hcl

@@ -0,0 +1,14 @@
+server {
+  api {
+    endpoint "/**" {
+      custom_log_fields = foo() # error!
+      response {
+        status = 204
+      }
+    }
+  }
+}
+
+settings {
+  log_level = "debug"
+}