/*
* 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.twill.internal;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.Service;
import org.apache.hadoop.security.Credentials;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.twill.filesystem.Location;
import org.apache.twill.internal.state.Message;
import org.apache.twill.internal.state.SystemMessages;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.util.concurrent.Executor;
/**
* A base implementation of {@link Service} handle secure token update.
*/
public abstract class AbstractTwillService implements Service {
private static final Logger LOG = LoggerFactory.getLogger(AbstractTwillService.class);
protected final Location applicationLocation;
protected volatile Credentials credentials;
protected AbstractTwillService(Location applicationLocation) {
this.applicationLocation = applicationLocation;
}
protected abstract Service getServiceDelegate();
/**
* Returns the location of the secure store, or {@code null} if either not running in secure mode or an error
* occur when trying to acquire the location.
*/
protected final Location getSecureStoreLocation() {
if (!UserGroupInformation.isSecurityEnabled()) {
return null;
}
try {
return applicationLocation.append(Constants.Files.CREDENTIALS);
} catch (IOException e) {
LOG.error("Failed to create secure store location.", e);
return null;
}
}
/**
* Attempts to handle secure store update.
*
* @param message The message received
* @return {@code true} if the message requests for secure store update, {@code false} otherwise.
*/
protected final boolean handleSecureStoreUpdate(Message message) {
if (!SystemMessages.SECURE_STORE_UPDATED.equals(message)) {
return false;
}
// If not in secure mode, simply ignore the message.
if (!UserGroupInformation.isSecurityEnabled()) {
return true;
}
try {
Credentials credentials = new Credentials();
Location location = getSecureStoreLocation();
DataInputStream input = new DataInputStream(new BufferedInputStream(location.getInputStream()));
try {
credentials.readTokenStorageStream(input);
} finally {
input.close();
}
UserGroupInformation.getCurrentUser().addCredentials(credentials);
this.credentials = credentials;
LOG.info("Secure store updated from {}.", location.toURI());
} catch (Throwable t) {
LOG.error("Failed to update secure store.", t);
}
return true;
}
@Override
public final ListenableFuture<State> start() {
return getServiceDelegate().start();
}
@Override
public final State startAndWait() {
return Futures.getUnchecked(start());
}
@Override
public final boolean isRunning() {
return getServiceDelegate().isRunning();
}
@Override
public final State state() {
return getServiceDelegate().state();
}
@Override
public final ListenableFuture<State> stop() {
return getServiceDelegate().stop();
}
@Override
public final State stopAndWait() {
return Futures.getUnchecked(stop());
}
@Override
public final void addListener(Listener listener, Executor executor) {
getServiceDelegate().addListener(listener, executor);
}
}