--- /dev/null
+
+/*************************************************************************//**
+ *
+ * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
+ *
+ * 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.onap.vnf.vlb.write;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ *
+ * Class that maintains a map of all the active vDNS instances.
+ * A vDNS instance is represented by its IP address and a flag
+ * that represents its status, i.e. enabled or disabled.
+ *
+ * Clients can update the vDNS map via NETCONF or RESTconf.
+ * Operations are translated by the Honeycomb agent into a JSON
+ * object that is persisted on disk (see Honeycomb distribution
+ * configuration for more information). The ElementCustomizer
+ * class then updates this map. Each operation results in a vLB
+ * setup change, e.g. GRE tunnels that connect the vLB to the
+ * vDNS instances are created or deleted, depending on the kind
+ * of operation that is invoked. Only vDNS instances for which
+ * the isEnabled flag is true are currently served by the vLB.
+ *
+ * The vLB setup and configuration is executed via shell scripts.
+ *
+ */
+
+public class DnsInstanceManager {
+
+ private static final Logger LOG = LoggerFactory.getLogger(DnsInstanceManager.class);
+ private Map<String, Boolean> dnsInstances = new HashMap<String, Boolean>();
+
+ /*
+ * Add a new DNS instance to the map and create a GRE tunnel
+ * towards that instance if isEnabled is set to true.
+ */
+ void addDnsInstance(String ipAddr, Boolean isEnabled) {
+ // Call updateDnsInstance in case the DNS instance already exists.
+ // This is somewhat redundant because Honeycomb already runs this check.
+ if(dnsInstances.containsKey(ipAddr)) {
+ updateDnsInstance(ipAddr, isEnabled);
+ return;
+ }
+
+ dnsInstances.put(ipAddr, isEnabled);
+ LOG.debug("DNS instance " + ipAddr + " with status isEnabled=" + isEnabled + " has been added.");
+
+ // Create a GRE tunnel towards the new DNS instance if isEnabled is true.
+ if(isEnabled) {
+ addGreTunnel(ipAddr);
+ }
+ }
+
+ /*
+ * Update an existing DNS instance and create or remove a GRE
+ * tunnel based on the current value of the isEnabled flag.
+ */
+ void updateDnsInstance(String ipAddr, Boolean isEnabled) {
+ // This is somewhat redundant because Honeycomb already runs this check.
+ if(dnsInstances.get(ipAddr) == isEnabled) {
+ LOG.debug("DNS instance " + ipAddr + " with status isEnabled=" + isEnabled + " already exists. No update is necessary.");
+ return;
+ }
+
+ dnsInstances.put(ipAddr, isEnabled);
+ LOG.debug("DNS instance " + ipAddr + " has been updated with status isEnabled=" + isEnabled + ".");
+
+ if(isEnabled) {
+ addGreTunnel(ipAddr);
+ }
+ else {
+ deleteGreTunnel(ipAddr);
+ }
+ }
+
+ /*
+ * Delete an existing DNS instance from the map and remove the
+ * GRE tunnel if isEnabled was set to true.
+ */
+ void deleteDnsInstance(String ipAddr) {
+ // This is somewhat redundant because Honeycomb already runs this check.
+ if(!dnsInstances.containsKey(ipAddr)) {
+ LOG.debug("DNS instance " + ipAddr + " doesn't exist.");
+ return;
+ }
+
+ // Remove a GRE tunnel towards this DNS instance if it exists.
+ if(dnsInstances.get(ipAddr)) {
+ deleteGreTunnel(ipAddr);
+ }
+
+ dnsInstances.remove(ipAddr);
+ }
+
+ /*
+ * Auxiliary function that calls a shell script to create a GRE tunnel towards a new vDNS instance.
+ */
+ private void addGreTunnel(String ipAddr) {
+ String script = new String("bash /opt/add_dns.sh " + ipAddr);
+ try {
+ Runtime.getRuntime().exec(script);
+ LOG.debug("New GRE tunnel towards DNS instance " + ipAddr + " created.");
+ } catch (IOException e) {
+ LOG.error("add_dns.sh returned an error.");
+ e.printStackTrace();
+ }
+ }
+
+ /*
+ * Auxiliary function that calls a shell script to delete a GRE tunnel towards a vDNS instance.
+ */
+ private void deleteGreTunnel(String ipAddr) {
+ String script = new String("bash /opt/remove_dns.sh " + ipAddr);
+ try {
+ Runtime.getRuntime().exec(script);
+ LOG.debug("GRE tunnel towards DNS instance " + ipAddr + " removed.");
+ } catch (IOException e) {
+ LOG.error("remove_dns.sh returned an error.");
+ e.printStackTrace();
+ }
+ }
+}
Code Review / demo.git / blobdiff