/**
* 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.cli;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import org.apache.whirr.command.Command;
import org.apache.whirr.service.ClusterActionHandler;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.ServiceLoader;
import java.util.SortedSet;
/**
* The entry point for the Whirr CLI.
*/
public class Main {
private Map<String, Command> commandMap = Maps.newLinkedHashMap();
private int maxLen = 0;
Main(Command... commands) throws IOException {
for (Command command : commands) {
commandMap.put(command.getName(), command);
maxLen = Math.max(maxLen, command.getName().length());
}
}
int run(InputStream in, PrintStream out, PrintStream err,
List<String> list) throws Exception {
if (list.isEmpty()) {
printUsage(out);
return -1;
}
Command command = commandMap.get(list.get(0));
if (command == null) {
err.printf("Unrecognized command '%s'\n", list.get(0));
err.println();
printUsage(err);
return -1;
}
return command.run(in, out, err, list.subList(1, list.size()));
}
private void printUsage(PrintStream stream) {
stream.println("Usage: whirr COMMAND [ARGS]");
stream.println("where COMMAND may be one of:");
stream.println();
for (Command command : commandMap.values()) {
stream.printf("%" + maxLen + "s %s\n", command.getName(),
command.getDescription());
}
stream.println();
stream.println("Available roles for instances:");
for(String roleName : getSortedRoleNames()) {
stream.println(" " + roleName);
}
}
private static SortedSet<String> getSortedRoleNames() {
ServiceLoader<ClusterActionHandler> loader =
ServiceLoader.load(ClusterActionHandler.class);
SortedSet<String> roles = Sets.newTreeSet();
for(ClusterActionHandler handler : loader) {
roles.add(handler.getRole());
}
return roles;
}
public static void main(String... args) throws Exception {
ServiceLoader<Command> loader = ServiceLoader.load(Command.class);
Main main = new Main(Lists.newArrayList(loader).toArray(new Command[0]));
int rc = main.run(System.in, System.out, System.err, Arrays.asList(args));
System.exit(rc);
}
}