org.apache.inlong.sort.filesystem.shaded.com.amazonaws.regions.InstanceMetadataRegionProvider Maven / Gradle / Ivy
/*
* Copyright 2011-2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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 com.amazonaws.regions;
import com.amazonaws.AmazonClientException;
import com.amazonaws.SDKGlobalConfiguration;
import com.amazonaws.util.EC2MetadataUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Attempts to load region information from the EC2 Metadata service. If the application is not
* running on EC2 or {@link SDKGlobalConfiguration#isEc2MetadataDisabled()} returns true,
* this provider will return null.
*/
public class InstanceMetadataRegionProvider extends AwsRegionProvider {
private static final Log LOG = LogFactory.getLog(InstanceMetadataRegionProvider.class);
/**
* Cache region as it will not change during the lifetime of the JVM.
*/
private volatile String region;
/**
* @throws AmazonClientException if {@link SDKGlobalConfiguration#isEc2MetadataDisabled()} is true
*/
@Override
public String getRegion() {
if (SDKGlobalConfiguration.isEc2MetadataDisabled()) {
throw new AmazonClientException("AWS_EC2_METADATA_DISABLED is set to true, not loading region from EC2 Instance "
+ "Metadata service");
}
if (region == null) {
synchronized (this) {
if (region == null) {
this.region = tryDetectRegion();
}
}
}
return region;
}
private String tryDetectRegion() {
try {
return EC2MetadataUtils.getEC2InstanceRegion();
} catch (AmazonClientException sce) {
LOG.debug("Ignoring failure to retrieve the region: " + sce.getMessage());
return null;
}
}
}