ONOS-2744 Adding a small app to manage cluster IP alias; requires arping tool.

Change-Id: Ib7032586206542c1db67d248196ad8a883d67b51

+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 2014 Open Networking Laboratory
+  ~
+  ~ 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.
+  -->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onosproject</groupId>
+        <artifactId>onos-apps</artifactId>
+        <version>1.3.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-app-cip</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>Cluster IP alias</description>
+
+    <properties>
+        <onos.app.name>org.onosproject.cip</onos.app.name>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.osgi</groupId>
+            <artifactId>org.osgi.compendium</artifactId>
+        </dependency>
+    </dependencies>
+
+</project>

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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.cip;
+
+import com.google.common.io.ByteStreams;
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Modified;
+import org.apache.felix.scr.annotations.Property;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.onosproject.cfg.ComponentConfigService;
+import org.onosproject.cluster.ClusterService;
+import org.onosproject.cluster.LeadershipEvent;
+import org.onosproject.cluster.LeadershipEventListener;
+import org.onosproject.cluster.LeadershipService;
+import org.onosproject.cluster.NodeId;
+import org.osgi.service.component.ComponentContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.Dictionary;
+import java.util.Objects;
+import java.util.Properties;
+
+import static com.google.common.base.Strings.isNullOrEmpty;
+import static org.onlab.util.Tools.get;
+
+/**
+ * Manages cluster IP address alias.
+ *
+ * To use the application, simply install it on ONOS and then configure it
+ * with the desired alias IP/mask/adapter configuration.
+ *
+ * If you are running it using upstart, you can also add the following
+ * command to the /opt/onos/options file:
+ *
+ * sudo ifconfig eth0:0 down       # use the desired alias adapter
+ *
+ * This will make sure that if the process is killed abruptly, the IP alias
+ * will be dropped upon respawn.
+ */
+@Component(immediate = true)
+public class ClusterIpManager {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private static final String CLUSTER_IP = "cluster/ip";
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ClusterService clusterService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected LeadershipService leadershipService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ComponentConfigService cfgService;
+
+    private final LeadershipEventListener listener = new InternalLeadershipListener();
+
+    private NodeId localId;
+    private boolean wasLeader = false;
+
+    // By default there is no IP; this has to be configured
+    @Property(name = "aliasIp", value = "", label = "Alias IP address")
+    private String aliasIp = "";
+
+    public static final String DEFAULT_MASK = "255.255.0.0";
+    @Property(name = "aliasMask", value = DEFAULT_MASK, label = "Alias IP mask")
+    private String aliasMask = DEFAULT_MASK;
+
+    public static final String ETH_0 = "eth0:0";
+    @Property(name = "aliasAdapter", value = ETH_0, label = "Alias IP adapter")
+    private String aliasAdapter = ETH_0;
+
+    @Activate
+    protected void activate(ComponentContext context) {
+        cfgService.registerProperties(getClass());
+
+        localId = clusterService.getLocalNode().id();
+        processLeadershipChange(leadershipService.getLeader(CLUSTER_IP));
+
+        leadershipService.addListener(listener);
+        leadershipService.runForLeadership(CLUSTER_IP);
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate(ComponentContext context) {
+        cfgService.unregisterProperties(getClass(), false);
+
+        removeIpAlias(aliasIp, aliasMask, aliasAdapter);
+
+        leadershipService.removeListener(listener);
+        leadershipService.withdraw(CLUSTER_IP);
+        log.info("Stopped");
+    }
+
+    @Modified
+    protected void modified(ComponentContext context) {
+        log.info("Received configuration change...");
+        Dictionary<?, ?> properties = context != null ? context.getProperties() : new Properties();
+        String newIp = get(properties, "aliasIp");
+        String newMask = get(properties, "aliasMask");
+        String newAdapter = get(properties, "aliasAdapter");
+
+        // Process any changes in the parameters...
+        if (!Objects.equals(newIp, aliasIp) ||
+                !Objects.equals(newMask, aliasMask) ||
+                !Objects.equals(newAdapter, aliasAdapter)) {
+            synchronized (this) {
+                log.info("Reconfiguring with aliasIp={}, aliasMask={}, aliasAdapter={}, wasLeader={}",
+                         newIp, newMask, newAdapter, wasLeader);
+                if (wasLeader) {
+                    removeIpAlias(aliasIp, aliasMask, aliasAdapter);
+                    addIpAlias(newIp, newMask, newAdapter);
+                }
+                aliasIp = newIp;
+                aliasMask = newMask;
+                aliasAdapter = newAdapter;
+            }
+        }
+    }
+
+    private synchronized void processLeadershipChange(NodeId newLeader) {
+        if (newLeader == null) {
+            return;
+        }
+        boolean isLeader = Objects.equals(newLeader, localId);
+        log.info("Processing leadership change; wasLeader={}, isLeader={}", wasLeader, isLeader);
+        if (!wasLeader && isLeader) {
+            // Gaining leadership, so setup the IP alias
+            addIpAlias(aliasIp, aliasMask, aliasAdapter);
+            wasLeader = true;
+        } else if (wasLeader && !isLeader) {
+            // Loosing leadership, so drop the IP alias
+            removeIpAlias(aliasIp, aliasMask, aliasAdapter);
+            wasLeader = false;
+        }
+    }
+
+    private synchronized void addIpAlias(String ip, String mask, String adapter) {
+        if (!isNullOrEmpty(ip) && !isNullOrEmpty(mask) && !isNullOrEmpty(adapter)) {
+            log.info("Adding IP alias {}/{} to {}", ip, mask, adapter);
+            execute("sudo ifconfig " + adapter + " " + ip + " netmask " + mask + " up", false);
+            execute("sudo /usr/sbin/arping -c 1 -I " + adapter + " " + ip, true);
+        }
+    }
+
+    private synchronized void removeIpAlias(String ip, String mask, String adapter) {
+        if (!isNullOrEmpty(ip) && !isNullOrEmpty(mask) && !isNullOrEmpty(adapter)) {
+            log.info("Removing IP alias from {}", adapter, false);
+            execute("sudo ifconfig " + adapter + " down", true);
+        }
+    }
+
+    private void execute(String command, boolean ignoreCode) {
+        try {
+            log.info("Executing [{}]", command);
+            Process process = Runtime.getRuntime().exec(command);
+            byte[] output = ByteStreams.toByteArray(process.getInputStream());
+            byte[] error = ByteStreams.toByteArray(process.getErrorStream());
+            int code = process.waitFor();
+            if (code != 0 && !ignoreCode) {
+                log.info("Command failed: status={}, output={}, error={}",
+                         code, new String(output), new String(error));
+            }
+        } catch (IOException e) {
+            log.error("Unable to execute command {}", command, e);
+        } catch (InterruptedException e) {
+            log.error("Interrupted executing command {}", command, e);
+        }
+    }
+
+    // Listens for leadership changes.
+    private class InternalLeadershipListener implements LeadershipEventListener {
+        @Override
+        public void event(LeadershipEvent event) {
+            if (event.subject().topic().equals(CLUSTER_IP)) {
+                processLeadershipChange(event.subject().leader());
+            }
+        }
+    }
+
+}

@@ -52,6 +52,7 @@
         <module>xos-integration</module>
         <module>xos-integration</module>
         <module>pcep-api</module>
         <module>pcep-api</module>
         <module>olt</module>
         <module>olt</module>
+        <module>cip</module>
         <module>flowanalyzer</module>
         <module>flowanalyzer</module>
         <module>vtnrsc</module>
         <module>vtnrsc</module>
         <module>vtn</module>
         <module>vtn</module>