org.apache.aurora.scheduler.base.CommandUtil.java Source code

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Here is the source code for org.apache.aurora.scheduler.base.CommandUtil.java

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/**
 * 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.apache.aurora.scheduler.base;

import java.util.List;

import com.google.common.base.Function;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.collect.Iterables;
import com.twitter.common.base.MorePreconditions;

import org.apache.mesos.Protos.CommandInfo;
import org.apache.mesos.Protos.CommandInfo.URI;

/**
 * Utility class for constructing {@link CommandInfo} objects given an executor URI.
 */
public final class CommandUtil {

    private static final Function<String, URI> STRING_TO_URI_RESOURCE = new Function<String, URI>() {
        @Override
        public URI apply(String resource) {
            return URI.newBuilder().setValue(resource).setExecutable(true).build();
        }
    };

    private CommandUtil() {
        // Utility class.
    }

    /**
     * Gets the last part of the path of a URI.
     *
     * @param uri URI to parse
     * @return The last segment of the URI.
     */
    public static String uriBasename(String uri) {
        int lastSlash = uri.lastIndexOf('/');
        if (lastSlash == -1) {
            return uri;
        } else {
            String basename = uri.substring(lastSlash + 1);
            MorePreconditions.checkNotBlank(basename, "URI must not end with a slash.");

            return basename;
        }
    }

    /**
     * Creates a description of a command that will fetch and execute the given URI to an executor
     * binary.
     *
     * @param executorUri A URI to the executor
     * @param executorResources A list of URIs to be fetched into the sandbox with the executor.
     * @return A populated CommandInfo with correct resources set and command set.
     */
    public static CommandInfo create(String executorUri, List<String> executorResources) {
        return create(executorUri, executorResources, "./", Optional.<String>absent()).build();
    }

    /**
     * Creates a description of a command that will fetch and execute the given URI to an executor
     * binary.
     *
     * @param executorUri A URI to the executor
     * @param executorResources A list of URIs to be fetched into the sandbox with the executor.
     * @param commandBasePath The relative base path of the executor.
     * @param extraArguments Extra command line arguments to add to the generated command.
     * @return A CommandInfo.Builder populated with resources and a command.
     */
    public static CommandInfo.Builder create(String executorUri, List<String> executorResources,
            String commandBasePath, Optional<String> extraArguments) {

        Preconditions.checkNotNull(executorResources);
        MorePreconditions.checkNotBlank(executorUri);
        MorePreconditions.checkNotBlank(commandBasePath);
        CommandInfo.Builder builder = CommandInfo.newBuilder();

        builder.addAllUris(Iterables.transform(executorResources, STRING_TO_URI_RESOURCE));
        builder.addUris(STRING_TO_URI_RESOURCE.apply(executorUri));

        String cmdLine = commandBasePath + uriBasename(executorUri) + " " + extraArguments.or("");
        return builder.setValue(cmdLine.trim());
    }
}