[ONOS-7914] Hostprovider support for kubernetes network

Change-Id: I1bbc08b7c819875932d0b72fa4bdee4de47c35dd
diff --git a/apps/k8s-networking/app/src/main/java/org/onosproject/k8snetworking/cli/K8sNetworkListCommand.java b/apps/k8s-networking/app/src/main/java/org/onosproject/k8snetworking/cli/K8sNetworkListCommand.java
new file mode 100644
index 0000000..82904a6
--- /dev/null
+++ b/apps/k8s-networking/app/src/main/java/org/onosproject/k8snetworking/cli/K8sNetworkListCommand.java
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2019-present Open Networking Foundation
+ *
+ * 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 org.onosproject.k8snetworking.cli;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.google.common.collect.Lists;
+import org.apache.karaf.shell.api.action.Command;
+import org.apache.karaf.shell.api.action.lifecycle.Service;
+import org.onosproject.cli.AbstractShellCommand;
+import org.onosproject.k8snetworking.api.K8sNetwork;
+import org.onosproject.k8snetworking.api.K8sNetworkService;
+
+import java.util.Comparator;
+import java.util.List;
+
+import static org.onosproject.k8snetworking.util.K8sNetworkingUtil.prettyJson;
+
+/**
+ * Lists kubernetes networks.
+ */
+@Service
+@Command(scope = "onos", name = "k8s-networks",
+        description = "Lists all kubernetes networks")
+public class K8sNetworkListCommand extends AbstractShellCommand {
+
+    private static final String FORMAT = "%-40s%-20s%-20s%-20s%-16s";
+
+    @Override
+    protected void doExecute() {
+        K8sNetworkService service = get(K8sNetworkService.class);
+        List<K8sNetwork> networks = Lists.newArrayList(service.networks());
+        networks.sort(Comparator.comparing(K8sNetwork::name));
+
+        if (outputJson()) {
+            print("%s", json(networks));
+        } else {
+            print(FORMAT, "ID", "Name", "Type", "SegId", "Gateway");
+
+            for (K8sNetwork net: networks) {
+                print(FORMAT, net.networkId(),
+                        net.name(),
+                        net.type().toString(),
+                        net.segmentId(),
+                        net.gatewayIp() == null ? "" : net.gatewayIp().toString());
+            }
+        }
+    }
+
+    private String json(List<K8sNetwork> networks) {
+        ObjectMapper mapper = new ObjectMapper();
+        ArrayNode result = mapper.createArrayNode();
+
+        for (K8sNetwork network : networks) {
+            result.add(jsonForEntity(network, K8sNetwork.class));
+        }
+        return prettyJson(mapper, result.toString());
+    }
+}