io.bootique.job.consul.lock.ConsulLockHandler Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of bootique-job-consul Show documentation
Provides the means to use Consul for locking job instances
There is a newer version: 3.0.M2
/*
 * Licensed to ObjectStyle LLC under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ObjectStyle LLC 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 io.bootique.job.consul.lock;

import com.orbitz.consul.KeyValueClient;
import io.bootique.job.JobMetadata;
import io.bootique.job.lock.LockHandler;
import io.bootique.job.runnable.JobOutcome;
import io.bootique.job.runnable.JobResult;
import io.bootique.job.runnable.RunnableJob;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.function.Supplier;

/**
 * @since 1.0.RC1
 */
public class ConsulLockHandler implements LockHandler {

    private static final Logger LOGGER = LoggerFactory.getLogger(ConsulLockHandler.class);

    private final KeyValueClient kvClient;
    private final Supplier consulSessionSupplier;
    private final String serviceGroup;

    public ConsulLockHandler(KeyValueClient kvClient, Supplier consulSessionSupplier, String serviceGroup) {
        this.kvClient = kvClient;
        this.consulSessionSupplier = consulSessionSupplier;
        this.serviceGroup = serviceGroup;
    }

    @Override
    public RunnableJob lockingJob(RunnableJob executable, JobMetadata metadata) {
        return () -> {
            String lockName = getLockName(metadata);

            String sessionId = consulSessionSupplier.get();

            LOGGER.info("Attempting to lock '{}'", lockName);
            boolean acquired = kvClient.acquireLock(lockName, sessionId);
            if (!acquired) {
                LOGGER.info("** Another job instance owns the lock. Skipping execution of '{}'", lockName);
                return new JobResult(metadata, JobOutcome.SKIPPED, null,
                        "Another job instance owns the lock. Skipping execution");
            }

            try {
                return executable.run();
            } finally {
                if (!kvClient.releaseLock(lockName, consulSessionSupplier.get())) {
                    LOGGER.error("Failed to release lock, manual intervention might be needed: " + lockName);
                }
            }
        };
    }

    private String getLockName(JobMetadata metadata) {
        String jobName = metadata.getName();
        return (serviceGroup == null || serviceGroup.isEmpty()) ?
                jobName : (serviceGroup + "/" + jobName);
    }
}