From 891d0cef66b1c3298c2476776b190b4286fc648f Mon Sep 17 00:00:00 2001
From: Peter Wilcsinszky <peter.wilcsinszky@axoflow.com>
Date: Mon, 24 Jul 2023 17:24:39 +0200
Subject: [PATCH] fix: refuse to reconcile logging with non-unique loggingRef

Signed-off-by: Peter Wilcsinszky <peter.wilcsinszky@axoflow.com>
---
 .../loggingref-check/loggingref-multi.yaml    | 24 +++++++++++++++++++
 controllers/logging/logging_controller.go     | 22 +++++++++++++++++
 2 files changed, 46 insertions(+)
 create mode 100644 config/samples/loggingref-check/loggingref-multi.yaml

diff --git a/config/samples/loggingref-check/loggingref-multi.yaml b/config/samples/loggingref-check/loggingref-multi.yaml
new file mode 100644
index 0000000000..b53ce59be6
--- /dev/null
+++ b/config/samples/loggingref-check/loggingref-multi.yaml
@@ -0,0 +1,24 @@
+apiVersion: logging.banzaicloud.io/v1beta1
+kind: Logging
+metadata:
+  name: one
+spec:
+  controlNamespace: default
+---
+apiVersion: logging.banzaicloud.io/v1beta1
+kind: Logging
+metadata:
+  name: two
+spec:
+  controlNamespace: default
+# this is invalid, as implicitly this will have the same loggingRef as the first one
+---
+apiVersion: logging.banzaicloud.io/v1beta1
+kind: Logging
+metadata:
+  name: three
+spec:
+  loggingRef: custom
+  controlNamespace: default
+  fluentd: {}
+# this must be processed regardless of the above as it has a unique loggingRef
diff --git a/controllers/logging/logging_controller.go b/controllers/logging/logging_controller.go
index 217cb0e269..53e89002dc 100644
--- a/controllers/logging/logging_controller.go
+++ b/controllers/logging/logging_controller.go
@@ -93,6 +93,28 @@ func (r *LoggingReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ct
 		return reconcile.Result{}, client.IgnoreNotFound(err)
 	}
 
+	allLoggings := &loggingv1beta1.LoggingList{}
+	if err := r.Client.List(ctx, allLoggings); err != nil {
+		return reconcile.Result{}, errors.WrapIf(err, "listing logging resources")
+	}
+
+	loggingsForTheSameRef := make([]string, 0)
+	for _, l := range allLoggings.Items {
+		if l.Name == logging.Name {
+			continue
+		}
+		if l.Spec.LoggingRef == logging.Spec.LoggingRef {
+			loggingsForTheSameRef = append(loggingsForTheSameRef, l.Name)
+		}
+	}
+
+	if len(loggingsForTheSameRef) > 0 {
+		problem := fmt.Sprintf("multiple other logging resources exist with the same loggingRef: %s",
+			strings.Join(loggingsForTheSameRef, ","))
+		logging.Status.Problems = []string{problem}
+		return reconcile.Result{}, errors.New(problem)
+	}
+
 	if err := r.Client.List(ctx, &v1.ServiceMonitorList{}); err == nil {
 		//nolint:staticcheck
 		ctx = context.WithValue(ctx, resources.ServiceMonitorKey, true)