From d3a52e214a4e03ab7d3cdd3d1c7d8bd102807704 Mon Sep 17 00:00:00 2001
From: AlinsRan <rongxin@api7.ai>
Date: Wed, 22 Jul 2026 08:38:28 +0800
Subject: [PATCH] fix: trim whitespace in comma-separated annotation values

GetStringsAnnotation split values on commas without trimming, so values
like "127.0.0.1, 0.0.0.0" produced a leading-space element that broke IP
validation and stalled sync. Trim each element and drop blanks.

Sync from apache/apisix-ingress-controller#2815 (fixes #2723)
---
 internal/adc/translator/annotations/types.go  |  8 +-
 .../adc/translator/annotations/types_test.go  | 74 +++++++++++++++++++
 2 files changed, 81 insertions(+), 1 deletion(-)
 create mode 100644 internal/adc/translator/annotations/types_test.go

diff --git a/internal/adc/translator/annotations/types.go b/internal/adc/translator/annotations/types.go
index 61ef517f..4117b3f2 100644
--- a/internal/adc/translator/annotations/types.go
+++ b/internal/adc/translator/annotations/types.go
@@ -131,7 +131,13 @@ func (e *extractor) GetStringsAnnotation(name string) []string {
 	if value == "" {
 		return nil
 	}
-	return strings.Split(value, ",")
+	var result []string
+	for _, item := range strings.Split(value, ",") {
+		if item = strings.TrimSpace(item); item != "" {
+			result = append(result, item)
+		}
+	}
+	return result
 }
 
 func (e *extractor) GetBoolAnnotation(name string) bool {
diff --git a/internal/adc/translator/annotations/types_test.go b/internal/adc/translator/annotations/types_test.go
new file mode 100644
index 00000000..1f324d51
--- /dev/null
+++ b/internal/adc/translator/annotations/types_test.go
@@ -0,0 +1,74 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License.  You may obtain a copy of the License at
+//
+//	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package annotations
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetStringsAnnotation(t *testing.T) {
+	const key = "test-key"
+	testCases := []struct {
+		name        string
+		annotations map[string]string
+		expected    []string
+	}{
+		{
+			name:        "no spaces",
+			annotations: map[string]string{key: "127.0.0.1,0.0.0.0"},
+			expected:    []string{"127.0.0.1", "0.0.0.0"},
+		},
+		{
+			name:        "spaces after comma",
+			annotations: map[string]string{key: "127.0.0.1, 0.0.0.0"},
+			expected:    []string{"127.0.0.1", "0.0.0.0"},
+		},
+		{
+			name:        "tabs and surrounding spaces",
+			annotations: map[string]string{key: " 127.0.0.1 ,\t0.0.0.0\t"},
+			expected:    []string{"127.0.0.1", "0.0.0.0"},
+		},
+		{
+			name:        "empty and blank elements",
+			annotations: map[string]string{key: "127.0.0.1,, ,0.0.0.0,"},
+			expected:    []string{"127.0.0.1", "0.0.0.0"},
+		},
+		{
+			name:        "single value",
+			annotations: map[string]string{key: "127.0.0.1"},
+			expected:    []string{"127.0.0.1"},
+		},
+		{
+			name:        "all blank elements",
+			annotations: map[string]string{key: " , ,\t"},
+			expected:    nil,
+		},
+		{
+			name:        "absent annotation",
+			annotations: map[string]string{},
+			expected:    nil,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			e := NewExtractor(tc.annotations)
+			assert.Equal(t, tc.expected, e.GetStringsAnnotation(key))
+		})
+	}
+}