[ONOS-7732] Automating switch workflow: api, app, and sample workflows

Change-Id: Iee87d4fe6cf61c1f8904d1d77df5f913a712b64a
diff --git a/apps/workflow/api/src/main/java/org/onosproject/workflow/api/WorkflowDescription.java b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/WorkflowDescription.java
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+++ b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/WorkflowDescription.java
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+/*
+ * Copyright 2018-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.workflow.api;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import java.net.URI;
+
+
+/**
+ * interface for workflow description.
+ */
+public interface WorkflowDescription {
+
+    /**
+     * Workflow workplace field name.
+     */
+    String WF_WORKPLACE = "workplace";
+
+    /**
+     * Workflow ID field name.
+     */
+    String WF_ID = "id";
+
+    /**
+     * Workflow data field name.
+     */
+    String WF_DATA = "data";
+
+    /**
+     * Gets workplace name.
+     * @return workplace name
+     */
+    String workplaceName();
+
+    /**
+     * Gets workflow ID.
+     * @return workflow ID
+     */
+    URI id();
+
+    /**
+     * Gets workflow context name.
+     * @return workflow context name
+     */
+    String workflowContextName();
+
+    /**
+     * Gets workflow data model.
+     * @return workflow data model
+     */
+    JsonNode data();
+
+    /**
+     * Gets json of workflow description.
+     * @return json of workflow description
+     */
+    JsonNode toJson();
+}