ONOS audit REST API support

Change-Id: Ic2910785f1f16fe5e36b33c1a73f44539cd8fbea
diff --git a/utils/rest/src/main/java/org/onlab/rest/AuditFilter.java b/utils/rest/src/main/java/org/onlab/rest/AuditFilter.java
new file mode 100644
index 0000000..0f098ac
--- /dev/null
+++ b/utils/rest/src/main/java/org/onlab/rest/AuditFilter.java
@@ -0,0 +1,136 @@
+/*
+ * Copyright 2016-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.onlab.rest;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.apache.commons.io.IOUtils;
+import org.slf4j.Logger;
+
+import javax.ws.rs.container.ContainerRequestContext;
+import javax.ws.rs.container.ContainerRequestFilter;
+import javax.ws.rs.container.ContainerResponseContext;
+import javax.ws.rs.container.ContainerResponseFilter;
+import java.io.IOException;
+
+import static org.onlab.util.Tools.readTreeFromStream;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * FIlter for logging all REST Api http requests and details of request and response.
+ */
+
+public class AuditFilter implements ContainerRequestFilter, ContainerResponseFilter {
+
+    private static Logger log = getLogger(AuditFilter.class);
+    private ObjectMapper mapper = new ObjectMapper();
+    private final String separator = "  |  ";
+
+    private static boolean disableForTests = false;
+    private static String auditFile = "all";
+    private static boolean auditEnabled = false;
+
+    @Override
+    public void filter(ContainerRequestContext requestContext) throws IOException {
+        if (disableForTests) {
+            return;
+        }
+        if (isEnabled()) {
+            String requestBody = (requestContext.hasEntity() ?
+                    (readTreeFromStream(mapper, requestContext.getEntityStream()).toString()) : "");
+            requestContext.setProperty("requestBody", requestBody);
+            requestContext.setProperty("auditLog", "Path: " + requestContext.getUriInfo().getPath() + separator
+                    + "Method: " + requestContext.getMethod() + separator
+                    + (requestContext.getMethod().equals("PUT") ?
+                    ("Path_Parameters: " + requestContext.getUriInfo().getPathParameters().toString() + separator
+                            + "Query_Parameters: " + requestContext.getUriInfo().getQueryParameters().toString()
+                            + separator + "Request_Body: " + requestBody) : ""));
+            requestContext.setEntityStream(IOUtils.toInputStream(requestBody));
+        }
+    }
+
+    @Override
+    public void filter(ContainerRequestContext containerRequestContext,
+                       ContainerResponseContext containerResponseContext) throws IOException {
+        if (disableForTests) {
+            return;
+        }
+        if (isEnabled()) {
+            containerRequestContext.setProperty("auditLog", containerRequestContext.getProperty("auditLog") + separator
+                    + "Status: " + containerResponseContext.getStatusInfo().toString());
+            saveAuditLog(containerRequestContext.getProperty("auditLog").toString());
+        }
+    }
+
+    /**
+     * To disable unit testing for this class.
+     */
+    public static void disableForTests() {
+        disableForTests = true;
+    }
+
+    /**
+     * To save audit logs into the log file.
+     *
+     * @param msg audit message.
+     */
+    private void saveAuditLog(String msg) {
+        if (isEnabled()) {
+            if (auditFile.equals("all")) {
+                log.info(msg);
+                log.info("AuditLog : " + msg);
+            } else if (auditFile.equals("karaf")) {
+                log.info(msg);
+            } else if (auditFile.equals("audit")) {
+                log.info("AuditLog : " + msg);
+            }
+        }
+    }
+
+    /**
+     * To check if REST API Audit is enabled.
+     *
+     * @return true if the REST API Audit is enabled.
+     */
+    private static boolean isEnabled() {
+        return auditEnabled;
+    }
+
+    /**
+     * To enable REST API Audit.
+     */
+    public static void enableAudit() {
+        auditEnabled = true;
+    }
+
+    /**
+     * To disable REST API Audit.
+     */
+    public static void disableAudit() {
+        auditEnabled = false;
+    }
+
+    /**
+     * To set audit file type which REST API Audit logs must be saved.
+     *
+     * @param auditFile file that REST API Audit logs are saved.
+     */
+    public static void setAuditFile(String auditFile) {
+        AuditFilter.auditFile = auditFile;
+    }
+
+
+}