org.apache.whirr.util.Utils.java Source code

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Here is the source code for org.apache.whirr.util.Utils.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.whirr.util;

import java.io.PrintStream;
import java.util.Map;

import org.apache.whirr.Cluster;
import org.apache.whirr.Cluster.Instance;
import org.apache.whirr.ClusterSpec;

import com.google.common.base.Functions;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;

public class Utils {
    /**
     * converts a map to a loading cache.
     */
    public static <K, V> LoadingCache<K, V> convertMapToLoadingCache(Map<K, V> in) {
        return CacheBuilder.newBuilder().build(CacheLoader.from(Functions.forMap(in)));
    }

    /**
     * Prints ssh commands that can be used to login into the nodes
     *
     * @param out
     * @param clusterSpec
     * @param cluster
     */
    public static void printSSHConnectionDetails(PrintStream out, ClusterSpec clusterSpec, Cluster cluster,
            int maxPrint) {
        out.println("\nYou can log into instances using the following ssh commands:");

        String user = clusterSpec.getBootstrapUser() != null ? clusterSpec.getBootstrapUser()
                : clusterSpec.getClusterUser();

        String pkFile = clusterSpec.getPrivateKeyFile().getAbsolutePath();

        int counter = 0;
        for (Instance instance : cluster.getInstances()) {

            out.printf("'ssh -i %s -o \"UserKnownHostsFile /dev/null\" -o StrictHostKeyChecking=no %s@%s'\n",
                    pkFile, user, instance.getPublicIp());

            if (counter > maxPrint) {
                out.println("... Too many instances, truncating.");
                break;
            }
            counter++;
        }
    }
}