istioctl miss to append ipv6 domain when using istioctl pc route (ist…

…io#38262)

* istioctl miss to append ipv6 domain when using istioctl pc route

* add test case for describeRouteDomains

istioctl/pkg/writer/envoy/configdump/route.go

@@ -100,6 +100,12 @@ func describeRouteDomains(domains []string) string {
 	for _, d := range domains {
 		if !strings.Contains(d, ":") {
 			withoutPort = append(withoutPort, d)
+			// if the domain contains IPv6, such as [fd00:10:96::7fc7] and [fd00:10:96::7fc7]:8090
+		} else if strings.Count(d, ":") > 2 {
+			// if the domain is only a IPv6 address, such as [fd00:10:96::7fc7], append it
+			if strings.HasSuffix(d, "]") {
+				withoutPort = append(withoutPort, d)
+			}
 		}
 	}
 	withoutPort = unexpandDomains(withoutPort)

istioctl/pkg/writer/envoy/configdump/route_test.go

@@ -13,3 +13,54 @@
 // limitations under the License.
 
 package configdump
+
+import (
+	"testing"
+)
+
+func TestDescribeRouteDomains(t *testing.T) {
+	tests := []struct {
+		desc     string
+		domains  []string
+		expected string
+	}{
+		{
+			desc:     "test zero domain",
+			domains:  []string{},
+			expected: "",
+		},
+		{
+			desc:     "test only one domain",
+			domains:  []string{"example.com"},
+			expected: "example.com",
+		},
+		{
+			desc:     "test domains with port",
+			domains:  []string{"example.com", "example.com:8080"},
+			expected: "example.com",
+		},
+		{
+			desc:     "test domains with ipv4 addresses",
+			domains:  []string{"example.com", "example.com:8080", "1.2.3.4", "1.2.3.4:8080"},
+			expected: "example.com, 1.2.3.4",
+		},
+		{
+			desc:     "test domains with ipv6 addresses",
+			domains:  []string{"example.com", "example.com:8080", "[fd00:10:96::7fc7]", "[fd00:10:96::7fc7]:8080"},
+			expected: "example.com, [fd00:10:96::7fc7]",
+		},
+		{
+			desc:     "test with more domains",
+			domains:  []string{"example.com", "example.com:8080", "www.example.com", "www.example.com:8080", "[fd00:10:96::7fc7]", "[fd00:10:96::7fc7]:8080"},
+			expected: "example.com, www.example.com + 1 more...",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.desc, func(t *testing.T) {
+			if got := describeRouteDomains(tt.domains); got != tt.expected {
+				t.Errorf("%s: expect %v got %v", tt.desc, tt.expected, got)
+			}
+		})
+	}
+}