Java tutorial
/* * Licensed to Elasticsearch under one or more contributor * license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright * ownership. Elasticsearch 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.elasticsearch.discovery.ec2; import java.io.Closeable; import java.io.IOException; import java.util.Random; import com.amazonaws.AmazonClientException; import com.amazonaws.AmazonWebServiceRequest; import com.amazonaws.ClientConfiguration; import com.amazonaws.auth.AWSCredentialsProvider; import com.amazonaws.auth.BasicAWSCredentials; import com.amazonaws.auth.DefaultAWSCredentialsProviderChain; import com.amazonaws.http.IdleConnectionReaper; import com.amazonaws.internal.StaticCredentialsProvider; import com.amazonaws.retry.RetryPolicy; import com.amazonaws.services.ec2.AmazonEC2; import com.amazonaws.services.ec2.AmazonEC2Client; import org.apache.logging.log4j.Logger; import org.elasticsearch.common.Randomness; import org.elasticsearch.common.Strings; import org.elasticsearch.common.component.AbstractComponent; import org.elasticsearch.common.settings.SecureString; import org.elasticsearch.common.settings.Settings; class AwsEc2ServiceImpl extends AbstractComponent implements AwsEc2Service, Closeable { public static final String EC2_METADATA_URL = "http://169.254.169.254/latest/meta-data/"; private AmazonEC2Client client; AwsEc2ServiceImpl(Settings settings) { super(settings); } @Override public synchronized AmazonEC2 client() { if (client != null) { return client; } this.client = new AmazonEC2Client(buildCredentials(logger, settings), buildConfiguration(logger, settings)); String endpoint = findEndpoint(logger, settings); if (endpoint != null) { client.setEndpoint(endpoint); } return this.client; } protected static AWSCredentialsProvider buildCredentials(Logger logger, Settings settings) { AWSCredentialsProvider credentials; try (SecureString key = ACCESS_KEY_SETTING.get(settings); SecureString secret = SECRET_KEY_SETTING.get(settings)) { if (key.length() == 0 && secret.length() == 0) { logger.debug( "Using either environment variables, system properties or instance profile credentials"); credentials = new DefaultAWSCredentialsProviderChain(); } else { logger.debug("Using basic key/secret credentials"); credentials = new StaticCredentialsProvider( new BasicAWSCredentials(key.toString(), secret.toString())); } } return credentials; } protected static ClientConfiguration buildConfiguration(Logger logger, Settings settings) { ClientConfiguration clientConfiguration = new ClientConfiguration(); // the response metadata cache is only there for diagnostics purposes, // but can force objects from every response to the old generation. clientConfiguration.setResponseMetadataCacheSize(0); clientConfiguration.setProtocol(PROTOCOL_SETTING.get(settings)); if (PROXY_HOST_SETTING.exists(settings)) { String proxyHost = PROXY_HOST_SETTING.get(settings); Integer proxyPort = PROXY_PORT_SETTING.get(settings); try (SecureString proxyUsername = PROXY_USERNAME_SETTING.get(settings); SecureString proxyPassword = PROXY_PASSWORD_SETTING.get(settings)) { clientConfiguration.withProxyHost(proxyHost).withProxyPort(proxyPort) .withProxyUsername(proxyUsername.toString()).withProxyPassword(proxyPassword.toString()); } } // Increase the number of retries in case of 5xx API responses final Random rand = Randomness.get(); RetryPolicy retryPolicy = new RetryPolicy(RetryPolicy.RetryCondition.NO_RETRY_CONDITION, new RetryPolicy.BackoffStrategy() { @Override public long delayBeforeNextRetry(AmazonWebServiceRequest originalRequest, AmazonClientException exception, int retriesAttempted) { // with 10 retries the max delay time is 320s/320000ms (10 * 2^5 * 1 * 1000) logger.warn("EC2 API request failed, retry again. Reason was:", exception); return 1000L * (long) (10d * Math.pow(2, retriesAttempted / 2.0d) * (1.0d + rand.nextDouble())); } }, 10, false); clientConfiguration.setRetryPolicy(retryPolicy); clientConfiguration.setSocketTimeout((int) READ_TIMEOUT_SETTING.get(settings).millis()); return clientConfiguration; } protected static String findEndpoint(Logger logger, Settings settings) { String endpoint = null; if (ENDPOINT_SETTING.exists(settings)) { endpoint = ENDPOINT_SETTING.get(settings); logger.debug("using explicit ec2 endpoint [{}]", endpoint); } return endpoint; } @Override public void close() throws IOException { if (client != null) { client.shutdown(); } // Ensure that IdleConnectionReaper is shutdown IdleConnectionReaper.shutdown(); } }