Import k8s client deps, support inject k8s API server config

Change-Id: Iaf246a06462b8a878e93ef3f98da399c3600b129
diff --git a/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sApiConfig.java b/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sApiConfig.java
new file mode 100644
index 0000000..0c63733
--- /dev/null
+++ b/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sApiConfig.java
@@ -0,0 +1,157 @@
+/*
+ * 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.k8snode.api;
+
+import org.onlab.packet.IpAddress;
+
+/**
+ * Representation of configuration used in kubernetes API server.
+ */
+public interface K8sApiConfig {
+
+    /**
+     * Lists of authentication schemes.
+     */
+    enum Scheme {
+        /**
+         * Signifies that this is a HTTP authentication scheme.
+         */
+        HTTP,
+
+        /**
+         * Signifies that this is a HTTPS authentication scheme.
+         */
+        HTTPS,
+    }
+
+    /**
+     * Returns the authentication scheme.
+     *
+     * @return authentication scheme
+     */
+    Scheme scheme();
+
+    /**
+     * Returns the IP address of kubernetes API server.
+     *
+     * @return IP address of kubernetes API server
+     */
+    IpAddress ipAddress();
+
+    /**
+     * Returns the port number of kubernetes API server.
+     *
+     * @return port number of kubernetes API server
+     */
+    int port();
+
+    /**
+     * Returns the token used for authenticating to API server.
+     *
+     * @return token value
+     */
+    String token();
+
+    /**
+     * Returns the CA certificate data.
+     *
+     * @return CA certificate data
+     */
+    String caCertData();
+
+    /**
+     * Returns the client certificate data.
+     *
+     * @return client certificate data
+     */
+    String clientCertData();
+
+    /**
+     * Returns the client key data.
+     *
+     * @return client key data
+     */
+    String clientKeyData();
+
+    /**
+     * Builder of new API config entity.
+     */
+    interface Builder {
+
+        /**
+         * Builds an immutable kubernetes API config instance.
+         *
+         * @return kubernetes API config instance
+         */
+        K8sApiConfig build();
+
+        /**
+         * Returns kubernetes API server config builder with supplied scheme.
+         *
+         * @param scheme scheme of authentication
+         * @return kubernetes API config builder
+         */
+        Builder scheme(Scheme scheme);
+
+        /**
+         * Returns kubernetes API server config builder with supplied IP address.
+         *
+         * @param ipAddress IP address of kubernetes API server
+         * @return kubernetes API config builder
+         */
+        Builder ipAddress(IpAddress ipAddress);
+
+        /**
+         * Returns kubernetes API server config builder with supplied port number.
+         *
+         * @param port port number of kubernetes API server
+         * @return kubernetes API config builder
+         */
+        Builder port(int port);
+
+        /**
+         * Returns kubernetes API server config builder with supplied token.
+         *
+         * @param token token for authentication
+         * @return kubernetes API config builder
+         */
+        Builder token(String token);
+
+        /**
+         * Returns kubernetes API server config builder with supplied CA certificate data.
+         *
+         * @param caCertData CA certificate data
+         * @return kubernetes API config builder
+         */
+        Builder caCertData(String caCertData);
+
+        /**
+         * Returns kubernetes API server config builder with supplied client certificate data.
+         *
+         * @param clientCertData client certificate data
+         * @return kubernetes API config builder
+         */
+        Builder clientCertData(String clientCertData);
+
+        /**
+         * Returns kubernetes API server config builder with supplied client key data.
+         *
+         * @param clientKeyData client key data
+         * @return kubernetes API config builder
+         */
+        Builder clientKeyData(String clientKeyData);
+    }
+}