[memcached] Fix ServerListWithInet for IPv4

The brackets are required only for IPv6, with IPv4
it causes issues because cache doesn't get used as all the
servers are marked as dead as not resolved.

Resolves: https://issues.redhat.com/browse/OSPRH-20517
Related-Issue: https://issues.redhat.com/browse/OSPRH-12221

Author: karelyatin

apis/test/helpers/memcached.go

@@ -152,7 +152,7 @@ func (tc *TestHelper) SimulateMemcachedReady(name types.NamespacedName) {
 		serverListWithInet := []string{}
 		for i := 0; i < int(*mc.Spec.Replicas); i++ {
 			serverList = append(serverList, fmt.Sprintf("%s-%d.%s.%s.svc:11211", mc.Name, i, mc.Name, mc.Namespace))
-			serverListWithInet = append(serverListWithInet, fmt.Sprintf("inet:[%s-%d.%s.%s.svc]:11211", mc.Name, i, mc.Name, mc.Namespace))
+			serverListWithInet = append(serverListWithInet, fmt.Sprintf("inet:%s-%d.%s.%s.svc:11211", mc.Name, i, mc.Name, mc.Namespace))
 		}
 		mc.Status.ServerList = serverList
 		mc.Status.ServerListWithInet = serverListWithInet
@@ -177,7 +177,7 @@ func (tc *TestHelper) SimulateTLSMemcachedReady(name types.NamespacedName) {
 		serverListWithInet := []string{}
 		for i := 0; i < int(*mc.Spec.Replicas); i++ {
 			serverList = append(serverList, fmt.Sprintf("%s-%d.%s.%s.svc:11211", mc.Name, i, mc.Name, mc.Namespace))
-			serverListWithInet = append(serverListWithInet, fmt.Sprintf("inet:[%s-%d.%s.%s.svc]:11211", mc.Name, i, mc.Name, mc.Namespace))
+			serverListWithInet = append(serverListWithInet, fmt.Sprintf("inet:%s-%d.%s.%s.svc:11211", mc.Name, i, mc.Name, mc.Namespace))
 		}
 		mc.Status.ServerList = serverList
 		mc.Status.ServerListWithInet = serverListWithInet
@@ -203,7 +203,7 @@ func (tc *TestHelper) SimulateMTLSMemcachedReady(name types.NamespacedName) {
 		serverListWithInet := []string{}
 		for i := 0; i < int(*mc.Spec.Replicas); i++ {
 			serverList = append(serverList, fmt.Sprintf("%s-%d.%s.%s.svc:11211", mc.Name, i, mc.Name, mc.Namespace))
-			serverListWithInet = append(serverListWithInet, fmt.Sprintf("inet:[%s-%d.%s.%s.svc]:11211", mc.Name, i, mc.Name, mc.Namespace))
+			serverListWithInet = append(serverListWithInet, fmt.Sprintf("inet:%s-%d.%s.%s.svc:11211", mc.Name, i, mc.Name, mc.Namespace))
 		}
 		mc.Status.ServerList = serverList
 		mc.Status.ServerListWithInet = serverListWithInet
@@ -226,3 +226,28 @@ func (tc *TestHelper) GetDefaultMemcachedSpec() memcachedv1.MemcachedSpec {
 		},
 	}
 }
+
+// SimulateIPv6MemcachedReady simulates a ready state for a Memcached instance in a Kubernetes cluster with IPv6 server list formatting.
+func (tc *TestHelper) SimulateIPv6MemcachedReady(name types.NamespacedName) {
+	t.Eventually(func(g t.Gomega) {
+		mc := tc.GetMemcached(name)
+		mc.Status.ObservedGeneration = mc.Generation
+		mc.Status.Conditions.MarkTrue(condition.ReadyCondition, condition.ReadyMessage)
+		mc.Status.ReadyCount = *mc.Spec.Replicas
+
+		serverList := []string{}
+		serverListWithInet := []string{}
+		for i := 0; i < int(*mc.Spec.Replicas); i++ {
+			serverList = append(serverList, fmt.Sprintf("%s-%d.%s.%s.svc:11211", mc.Name, i, mc.Name, mc.Namespace))
+			serverListWithInet = append(serverListWithInet, fmt.Sprintf("inet6:[%s-%d.%s.%s.svc]:11211", mc.Name, i, mc.Name, mc.Namespace))
+		}
+		mc.Status.ServerList = serverList
+		mc.Status.ServerListWithInet = serverListWithInet
+
+		// This can return conflict so we have the t.Eventually block to retry
+		g.Expect(tc.K8sClient.Status().Update(tc.Ctx, mc)).To(t.Succeed())
+
+	}, tc.Timeout, tc.Interval).Should(t.Succeed())
+
+	tc.Logger.Info("Simulated IPv6 memcached ready", "on", name)
+}

controllers/memcached/memcached_controller.go

@@ -683,8 +683,11 @@ func (r *Reconciler) GetServerLists(
 		serverList = append(serverList, fmt.Sprintf("%s:%d", server, port))
 
 		// python-memcached requires inet(6) prefix according to the IP version
-		// used by the memcached server.
-		serverListWithInet = append(serverListWithInet, fmt.Sprintf("%s:[%s]:%d", prefix, server, memcached.MemcachedPort))
+		// used by the memcached server. IPv6 addresses also need to be wrapped in brackets.
+		if ipFamily == corev1.IPv6Protocol {
+			server = fmt.Sprintf("[%s]", server)
+		}
+		serverListWithInet = append(serverListWithInet, fmt.Sprintf("%s:%s:%d", prefix, server, memcached.MemcachedPort))
 	}
 
 	return serverList, serverListWithInet

tests/functional/memcached_controller_test.go

@@ -290,4 +290,70 @@ var _ = Describe("Memcached Controller", func() {
 			)
 		})
 	})
+
+	When("testing server list formatting", func() {
+		It("should format IPv4 server lists correctly (without brackets)", func() {
+			// Create a memcached instance for testing
+			memcachedSpec := GetDefaultMemcachedSpec()
+			memcachedSpec["replicas"] = 3
+			memcached := CreateMemcachedConfig(namespace, memcachedSpec)
+			memcachedName := types.NamespacedName{
+				Name:      memcached.GetName(),
+				Namespace: memcached.GetNamespace(),
+			}
+			DeferCleanup(th.DeleteInstance, memcached)
+
+			// Simulate IPv4 memcached ready (this uses the helper method which now correctly formats IPv4)
+			th.SimulateMemcachedReady(memcachedName)
+
+			// Verify the server list formatting
+			instance := GetMemcached(memcachedName)
+
+			// Verify serverList (should not have brackets)
+			Expect(instance.Status.ServerList).To(HaveLen(3))
+			for i := 0; i < 3; i++ {
+				expectedServer := fmt.Sprintf("%s-%d.%s.%s.svc:11211", instance.Name, i, instance.Name, instance.Namespace)
+				Expect(instance.Status.ServerList[i]).To(Equal(expectedServer))
+			}
+
+			// Verify serverListWithInet for IPv4 (should not have brackets around hostname)
+			Expect(instance.Status.ServerListWithInet).To(HaveLen(3))
+			for i := 0; i < 3; i++ {
+				expectedServerWithInet := fmt.Sprintf("inet:%s-%d.%s.%s.svc:11211", instance.Name, i, instance.Name, instance.Namespace)
+				Expect(instance.Status.ServerListWithInet[i]).To(Equal(expectedServerWithInet))
+			}
+		})
+
+		It("should format IPv6 server lists correctly (with brackets)", func() {
+			// Create a memcached instance for testing
+			memcachedSpec := GetDefaultMemcachedSpec()
+			memcachedSpec["replicas"] = 3
+			memcached := CreateMemcachedConfig(namespace, memcachedSpec)
+			memcachedName := types.NamespacedName{
+				Name:      memcached.GetName(),
+				Namespace: memcached.GetNamespace(),
+			}
+			DeferCleanup(th.DeleteInstance, memcached)
+
+			// Simulate IPv6 memcached ready
+			th.SimulateIPv6MemcachedReady(memcachedName)
+
+			// Verify the server list formatting
+			instance := GetMemcached(memcachedName)
+
+			// Verify serverList (should not have brackets - same as IPv4)
+			Expect(instance.Status.ServerList).To(HaveLen(3))
+			for i := 0; i < 3; i++ {
+				expectedServer := fmt.Sprintf("%s-%d.%s.%s.svc:11211", instance.Name, i, instance.Name, instance.Namespace)
+				Expect(instance.Status.ServerList[i]).To(Equal(expectedServer))
+			}
+
+			// Verify serverListWithInet for IPv6 (should have brackets around hostname)
+			Expect(instance.Status.ServerListWithInet).To(HaveLen(3))
+			for i := 0; i < 3; i++ {
+				expectedServerWithInet := fmt.Sprintf("inet6:[%s-%d.%s.%s.svc]:11211", instance.Name, i, instance.Name, instance.Namespace)
+				Expect(instance.Status.ServerListWithInet[i]).To(Equal(expectedServerWithInet))
+			}
+		})
+	})
 })

tests/kuttl/tests/memcached/02-assert.yaml

@@ -12,7 +12,7 @@ commands:
   - script: |
       # get the first memcached from serverListWithInet and validate
       template='{{ (index .status.serverListWithInet 0) }}'
-      regex="inet:\[memcached-0.memcached.$NAMESPACE.svc\]:11211"
+      regex="inet:memcached-0.memcached.$NAMESPACE.svc:11211"
       memcached=$(oc get -n $NAMESPACE memcached memcached -o go-template="$template")
       matches=$(echo "$memcached" | sed -e "s?$regex??")
       if [ -z "$matches" ]; then

tests/kuttl/tests/memcached/04-assert.yaml

@@ -34,7 +34,7 @@ commands:
       # Whether or not TLS is configured, the serverListWithInit always exposes port 11211
       # get the first memcached from serverListWithInet and validate
       template='{{ (index .status.serverListWithInet 0) }}'
-      regex="inet:\[memcached-0.memcached.$NAMESPACE.svc\]:11211"
+      regex="inet:memcached-0.memcached.$NAMESPACE.svc:11211"
       memcached=$(oc get -n $NAMESPACE memcached memcached -o go-template="$template")
       matches=$(echo "$memcached" | sed -e "s?$regex??")
       if [ -z "$matches" ]; then