HONEYCOMB-281 Loopback interface management

Change-Id: I7e4d817bb7dfe9ccd779e59347c956233c012e4a
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>

7 files changed, 306 insertions, 4 deletions

diff --git a/v3po/api/src/main/yang/v3po.yang b/v3po/api/src/main/yang/v3po.yang
index f272a489a..18b68620e 100644
--- a/v3po/api/src/main/yang/v3po.yang
+++ b/v3po/api/src/main/yang/v3po.yang
@@ -9,7 +9,8 @@ module v3po {
        - ingress/egress ACLs support
        - moved ACL definitions to vpp-acl module
        - updated l2 container constraint (permit IP address on BVI interface)
-       - added PID of vpp process to vpp-state";
+       - added PID of vpp process to vpp-state
+       - added support for Loopback interfaces";
   }
 
   revision "2015-01-05" {
@@ -70,6 +71,10 @@ module v3po {
     base if:interface-type;
   }
 
+  identity loopback {
+    base if:interface-type;
+  }
+
   identity l2-fib-action {
     description "Base identity for l2-fib actions";
   }
@@ -244,6 +249,14 @@ module v3po {
     }
   }
 
+  grouping loopback-interface-base-attributes {
+    leaf mac {
+      type yang:phys-address;
+      mandatory false;
+      description "Mac address of the loopback interface";
+    }
+  }
+
   grouping ethernet-base-attributes {
     leaf mtu {
       type uint16 {
@@ -436,6 +449,12 @@ module v3po {
       uses tap-interface-config-attributes;
     }
 
+    container loopback {
+      presence "Presence of this container indicates loopback nature of the interface";
+      when "../if:type = 'v3po:loopback'";
+      uses loopback-interface-base-attributes;
+    }
+
     container ethernet {
       when "../if:type = 'ianaift:ethernetCsmacd'";
       uses ethernet-base-attributes;
diff --git a/v3po/postman_rest_collection.json b/v3po/postman_rest_collection.json
index e25cfb6f2..15e61afdc 100644
--- a/v3po/postman_rest_collection.json
+++ b/v3po/postman_rest_collection.json
@@ -34,6 +34,17 @@
 			"collectionId": "e9ba4e80-fb4d-1eae-07e7-97b323164130"
 		},
 		{
+			"id": "f59ae95c-b691-1283-8b2b-539a00da0178",
+			"name": "Loopback",
+			"description": "",
+			"order": [
+				"3090675a-fb54-3cc8-71d7-0675b7b79eb8",
+				"9306bff2-f310-986e-44cf-7845ba82b980"
+			],
+			"owner": "45557",
+			"collectionId": "e9ba4e80-fb4d-1eae-07e7-97b323164130"
+		},
+		{
 			"id": "e742a44e-2e82-fe0c-d7c1-2f6b6bc1f0e9",
 			"name": "Bridge Domain management",
 			"description": "",
@@ -206,6 +217,46 @@
 	"published": false,
 	"requests": [
 		{
+			"id": "3090675a-fb54-3cc8-71d7-0675b7b79eb8",
+			"headers": "Authorization: Basic YWRtaW46YWRtaW4=\nContent-Type: application/json\n",
+			"url": "http://localhost:8183/restconf/config/ietf-interfaces:interfaces/interface/loop1",
+			"preRequestScript": "",
+			"pathVariables": {},
+			"method": "PUT",
+			"data": [],
+			"dataMode": "raw",
+			"version": 2,
+			"tests": "",
+			"currentHelper": "normal",
+			"helperAttributes": {},
+			"time": 1478080135790,
+			"name": "Add loopback ifc - cfg ",
+			"description": "create loop interface",
+			"collectionId": "5bad4634-e5cf-900e-9733-0976aa9bea64",
+			"responses": [],
+			"rawModeData": "{\r\n    \r\n    \"interface\": [\r\n        {\r\n            \"name\": \"loop1\",\r\n            \"description\": \"for testing purposes\",\r\n            \"type\": \"v3po:loopback\",\r\n            \"loopback\" :{\r\n                \"mac\" : \"00:ff:ff:ff:ff:ff\"\r\n            }\r\n        }\r\n    ]\r\n    \r\n}"
+		},
+		{
+			"id": "9306bff2-f310-986e-44cf-7845ba82b980",
+			"headers": "Authorization: Basic YWRtaW46YWRtaW4=\nContent-Type: application/json\n",
+			"url": "http://localhost:8183/restconf/config/ietf-interfaces:interfaces/interface/loop1",
+			"preRequestScript": "",
+			"pathVariables": {},
+			"method": "DELETE",
+			"data": [],
+			"dataMode": "raw",
+			"version": 2,
+			"tests": "",
+			"currentHelper": "normal",
+			"helperAttributes": {},
+			"time": 1478085084456,
+			"name": "Delete loopback ifc - cfg ",
+			"description": "delete loop interface intfc loop1",
+			"collectionId": "5bad4634-e5cf-900e-9733-0976aa9bea64",
+			"responses": [],
+			"rawModeData": ""
+		},
+		{
 			"id": "4fd61184-7a23-f84a-6734-b2c96d10c908",
 			"headers": "Authorization: Basic YWRtaW46YWRtaW4=\nContent-Type: application/json\n",
 			"url": "http://localhost:8183/restconf/config/ietf-interfaces:interfaces/interface/local0",
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/InterfacesWriterFactory.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/InterfacesWriterFactory.java
index 63593afd5..7bf5a432c 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/InterfacesWriterFactory.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/InterfacesWriterFactory.java
@@ -28,15 +28,16 @@ import io.fd.honeycomb.translate.v3po.interfaces.EthernetCustomizer;
 import io.fd.honeycomb.translate.v3po.interfaces.GreCustomizer;
 import io.fd.honeycomb.translate.v3po.interfaces.InterfaceCustomizer;
 import io.fd.honeycomb.translate.v3po.interfaces.L2Customizer;
+import io.fd.honeycomb.translate.v3po.interfaces.LoopbackCustomizer;
 import io.fd.honeycomb.translate.v3po.interfaces.ProxyArpCustomizer;
 import io.fd.honeycomb.translate.v3po.interfaces.RoutingCustomizer;
 import io.fd.honeycomb.translate.v3po.interfaces.TapCustomizer;
 import io.fd.honeycomb.translate.v3po.interfaces.VhostUserCustomizer;
 import io.fd.honeycomb.translate.v3po.interfaces.VxlanCustomizer;
 import io.fd.honeycomb.translate.v3po.interfaces.VxlanGpeCustomizer;
-import io.fd.honeycomb.translate.v3po.interfaces.acl.ingress.IetfAclCustomizer;
 import io.fd.honeycomb.translate.v3po.interfaces.acl.egress.EgressIetfAclWriter;
 import io.fd.honeycomb.translate.v3po.interfaces.acl.ingress.AclCustomizer;
+import io.fd.honeycomb.translate.v3po.interfaces.acl.ingress.IetfAclCustomizer;
 import io.fd.honeycomb.translate.v3po.interfaces.acl.ingress.IngressIetfAclWriter;
 import io.fd.honeycomb.translate.v3po.interfaces.ip.Ipv4AddressCustomizer;
 import io.fd.honeycomb.translate.v3po.interfaces.ip.Ipv4Customizer;
@@ -62,6 +63,7 @@ import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.interfaces._interface.Gre;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.interfaces._interface.IetfAcl;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.interfaces._interface.L2;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.interfaces._interface.Loopback;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.interfaces._interface.ProxyArp;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.interfaces._interface.Routing;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.interfaces._interface.Tap;
@@ -173,6 +175,10 @@ public final class InterfacesWriterFactory implements WriterFactory {
         final InstanceIdentifier<Tap> tapId = VPP_IFC_AUG_ID.child(Tap.class);
         registry.addBefore(new GenericWriter<>(tapId, new TapCustomizer(jvpp, ifcNamingContext)),
                 ifcId);
+        // Loopback(Needs to be executed before Interface customizer) =
+        final InstanceIdentifier<Loopback> loopbackId = VPP_IFC_AUG_ID.child(Loopback.class);
+        registry.addBefore(new GenericWriter<>(loopbackId, new LoopbackCustomizer(jvpp, ifcNamingContext)),
+                ifcId);
 
         // Gre(Needs to be executed before Interface customizer) =
         final InstanceIdentifier<Gre> greId = VPP_IFC_AUG_ID.child(Gre.class);
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfaces/LoopbackCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfaces/LoopbackCustomizer.java
new file mode 100644
index 000000000..47a71750d
--- /dev/null
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfaces/LoopbackCustomizer.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed 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 io.fd.honeycomb.translate.v3po.interfaces;
+
+import io.fd.honeycomb.translate.vpp.util.AbstractInterfaceTypeCustomizer;
+import io.fd.honeycomb.translate.vpp.util.JvppReplyConsumer;
+import io.fd.honeycomb.translate.vpp.util.MacTranslator;
+import io.fd.honeycomb.translate.vpp.util.NamingContext;
+import io.fd.honeycomb.translate.write.WriteContext;
+import io.fd.honeycomb.translate.write.WriteFailedException;
+import io.fd.vpp.jvpp.core.dto.CreateLoopback;
+import io.fd.vpp.jvpp.core.dto.CreateLoopbackReply;
+import io.fd.vpp.jvpp.core.dto.DeleteLoopback;
+import io.fd.vpp.jvpp.core.future.FutureJVppCore;
+import javax.annotation.Nonnull;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.InterfaceType;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.interfaces._interface.Loopback;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public final class LoopbackCustomizer extends AbstractInterfaceTypeCustomizer<Loopback>
+        implements MacTranslator, JvppReplyConsumer {
+
+    private static final Logger LOG = LoggerFactory.getLogger(LoopbackCustomizer.class);
+    private final NamingContext interfaceContext;
+
+    public LoopbackCustomizer(final FutureJVppCore vppApi, final NamingContext interfaceContext) {
+        super(vppApi);
+        this.interfaceContext = interfaceContext;
+    }
+
+    @Override
+    protected Class<? extends InterfaceType> getExpectedInterfaceType() {
+        return org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.Loopback.class;
+    }
+
+    @Override
+    protected final void writeInterface(@Nonnull final InstanceIdentifier<Loopback> id, @Nonnull final Loopback dataAfter,
+                                        @Nonnull final WriteContext writeContext)
+            throws WriteFailedException {
+        final String ifcName = id.firstKeyOf(Interface.class).getName();
+        createLoopback(id, ifcName, dataAfter, writeContext);
+    }
+
+    @Override
+    public void updateCurrentAttributes(@Nonnull final InstanceIdentifier<Loopback> id, @Nonnull final Loopback dataBefore,
+                                        @Nonnull final Loopback dataAfter, @Nonnull final WriteContext writeContext)
+            throws WriteFailedException {
+        throw new WriteFailedException.UpdateFailedException(id, dataBefore, dataAfter,
+                new UnsupportedOperationException("Modification of loopback interface is not supported"));
+    }
+
+    @Override
+    public void deleteCurrentAttributes(@Nonnull final InstanceIdentifier<Loopback> id, @Nonnull final Loopback dataBefore,
+                                        @Nonnull final WriteContext writeContext)
+            throws WriteFailedException {
+        final String ifcName = id.firstKeyOf(Interface.class).getName();
+
+        final int index;
+        try {
+            index = interfaceContext.getIndex(ifcName, writeContext.getMappingContext());
+        } catch (IllegalArgumentException e) {
+            throw new WriteFailedException.DeleteFailedException(id, e);
+        }
+
+        deleteLoopback(id, ifcName, index, dataBefore, writeContext);
+    }
+
+    private void createLoopback(final InstanceIdentifier<Loopback> id, final String swIfName, final Loopback loopback,
+                                final WriteContext writeContext) throws WriteFailedException {
+        LOG.debug("Setting loopback interface: {}. Loopback: {}", swIfName, loopback);
+
+        final CreateLoopback createLoopback = new CreateLoopback();
+        if (loopback.getMac() != null) {
+            createLoopback.macAddress = parseMac(loopback.getMac().getValue());
+        }
+        final CreateLoopbackReply reply =
+                getReplyForCreate(getFutureJVpp().createLoopback(createLoopback).toCompletableFuture(), id, loopback);
+
+        LOG.debug("Loopback set successfully for: {}, loopback: {}", swIfName, loopback);
+        // Add new interface to our interface context
+        interfaceContext.addName(reply.swIfIndex, swIfName, writeContext.getMappingContext());
+    }
+
+    private void deleteLoopback(final InstanceIdentifier<Loopback> id, final String swIfName, final int index,
+                           final Loopback dataBefore, final WriteContext writeContext)
+            throws WriteFailedException {
+        LOG.debug("Deleting loopback interface: {}. Loopback: {}", swIfName, dataBefore);
+        final DeleteLoopback deleteLoopback = new DeleteLoopback();
+        deleteLoopback.swIfIndex = index;
+        getReplyForDelete(getFutureJVpp().deleteLoopback(deleteLoopback).toCompletableFuture(), id);
+        LOG.debug("Loopback deleted successfully for: {}, loopback: {}", swIfName, dataBefore);
+        // Remove deleted interface from interface context
+        interfaceContext.removeName(swIfName, writeContext.getMappingContext());
+    }
+}
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfacesstate/InterfaceCustomizer.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfacesstate/InterfaceCustomizer.java
index fdb8397dd..4308f34a0 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfacesstate/InterfaceCustomizer.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfacesstate/InterfaceCustomizer.java
@@ -72,6 +72,11 @@ public class InterfaceCustomizer extends FutureJVppCustomizer
         this.interfaceDisableContext = interfaceDisableContext;
     }
 
+    public static void cacheInterfaceDump(final @Nonnull ReadContext context, final SwInterfaceDetailsReplyDump ifaces) {
+        context.getModificationCache().put(DUMPED_IFCS_CONTEXT_KEY, ifaces.swInterfaceDetails.stream()
+                .collect(Collectors.toMap(t -> t.swIfIndex, swInterfaceDetails -> swInterfaceDetails)));
+    }
+
     @Nonnull
     @SuppressWarnings("unchecked")
     public static Map<Integer, SwInterfaceDetails> getCachedInterfaceDump(@Nonnull final ModificationCache ctx) {
@@ -155,8 +160,7 @@ public class InterfaceCustomizer extends FutureJVppCustomizer
         }
 
         // Cache interfaces dump in per-tx context to later be used in readCurrentAttributes
-        context.getModificationCache().put(DUMPED_IFCS_CONTEXT_KEY, ifaces.swInterfaceDetails.stream()
-                .collect(Collectors.toMap(t -> t.swIfIndex, swInterfaceDetails -> swInterfaceDetails)));
+        cacheInterfaceDump(context, ifaces);
 
         final MappingContext mappingCtx = context.getMappingContext();
         final Set<Integer> interfacesIdxs = ifaces.swInterfaceDetails.stream()
diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfacesstate/InterfaceDataTranslator.java b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfacesstate/InterfaceDataTranslator.java
index 376b7863f..2864c6e6a 100644
--- a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfacesstate/InterfaceDataTranslator.java
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfacesstate/InterfaceDataTranslator.java
@@ -40,6 +40,7 @@ import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.Interface;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.Gauge64;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.GreTunnel;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.Loopback;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.Tap;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.VhostUser;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.VxlanGpeTunnel;
@@ -253,6 +254,10 @@ public interface InterfaceDataTranslator extends ByteDataTranslator, JvppReplyCo
             return VhostUser.class;
         }
 
+        if (interfaceName.startsWith("loop")) {
+            return Loopback.class;
+        }
+
         return EthernetCsmacd.class;
     }
 
diff --git a/v3po/v3po2vpp/src/test/java/io/fd/honeycomb/translate/v3po/interfaces/LoopbackCustomizerTest.java b/v3po/v3po2vpp/src/test/java/io/fd/honeycomb/translate/v3po/interfaces/LoopbackCustomizerTest.java
new file mode 100644
index 000000000..60af7a143
--- /dev/null
+++ b/v3po/v3po2vpp/src/test/java/io/fd/honeycomb/translate/v3po/interfaces/LoopbackCustomizerTest.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed 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 io.fd.honeycomb.translate.v3po.interfaces;
+
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import io.fd.honeycomb.translate.vpp.util.NamingContext;
+import io.fd.honeycomb.vpp.test.write.WriterCustomizerTest;
+import io.fd.vpp.jvpp.core.dto.CreateLoopback;
+import io.fd.vpp.jvpp.core.dto.CreateLoopbackReply;
+import io.fd.vpp.jvpp.core.dto.DeleteLoopback;
+import io.fd.vpp.jvpp.core.dto.DeleteLoopbackReply;
+import org.junit.Test;
+import org.mockito.invocation.InvocationOnMock;
+import org.mockito.stubbing.Answer;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.Interfaces;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.InterfaceKey;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.PhysAddress;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.VppInterfaceAugmentation;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.interfaces._interface.Loopback;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.interfaces._interface.LoopbackBuilder;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+public class LoopbackCustomizerTest extends WriterCustomizerTest {
+
+    private static final String IFC_TEST_INSTANCE = "ifc-test-instance";
+    private LoopbackCustomizer loopCustomizer;
+
+    @Override
+    public void setUp() throws Exception {
+        InterfaceTypeTestUtils.setupWriteContext(writeContext,
+            org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev161214.Loopback.class);
+        loopCustomizer = new LoopbackCustomizer(api, new NamingContext("ifcintest", IFC_TEST_INSTANCE));
+    }
+
+    @Test
+    public void testCreate() throws Exception {
+        doAnswer(new Answer() {
+
+            int idx = 0;
+
+            @Override
+            public Object answer(final InvocationOnMock invocation) throws Throwable {
+                final CreateLoopbackReply t = new CreateLoopbackReply();
+                t.swIfIndex = idx++;
+                return future(t);
+            }
+        }).when(api).createLoopback(any(CreateLoopback.class));
+
+        loopCustomizer.writeCurrentAttributes(getLoopbackId("loop"), getLoopbackData("ff:ff:ff:ff:ff:ff"), writeContext);
+        loopCustomizer.writeCurrentAttributes(getLoopbackId("loop2"), getLoopbackData("ff:ff:ff:ff:ff:ff"), writeContext);
+
+        verify(api, times(2)).createLoopback(any(CreateLoopback.class));
+        verify(mappingContext).put(eq(mappingIid("loop", IFC_TEST_INSTANCE)), eq(
+                mapping("loop", 0).get()));
+        verify(mappingContext).put(eq(mappingIid("loop2", IFC_TEST_INSTANCE)), eq(
+                mapping("loop2", 1).get()));
+    }
+
+    @Test
+    public void testDelete() throws Exception {
+        final CreateLoopbackReply t = new CreateLoopbackReply();
+        t.swIfIndex = 0;
+        doReturn(future(t)).when(api).createLoopback(any(CreateLoopback.class));
+
+        doReturn(future(new DeleteLoopbackReply())).when(api).deleteLoopback(any(DeleteLoopback.class));
+
+        loopCustomizer.writeCurrentAttributes(getLoopbackId("loop"), getLoopbackData("ff:ff:ff:ff:ff:ff"), writeContext);
+        defineMapping(mappingContext, "loop", 1, IFC_TEST_INSTANCE);
+        loopCustomizer.deleteCurrentAttributes(getLoopbackId("loop"), getLoopbackData("ff:ff:ff:ff:ff:ff"), writeContext);
+
+        verify(api).createLoopback(any(CreateLoopback.class));
+        verify(api).deleteLoopback(any(DeleteLoopback.class));
+        verify(mappingContext).delete(eq(mappingIid("loop", IFC_TEST_INSTANCE)));
+    }
+
+    private InstanceIdentifier<Loopback> getLoopbackId(final String loop) {
+        return InstanceIdentifier.create(Interfaces.class).child(Interface.class, new InterfaceKey(loop)).augmentation(
+            VppInterfaceAugmentation.class).child(Loopback.class);
+    }
+
+    private Loopback getLoopbackData(final String mac) {
+        return new LoopbackBuilder().setMac(new PhysAddress(mac)).build();
+    }
+}
\ No newline at end of file