com.netflix.iep.dynprop.RemoteConfigurationSource.java Source code

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Here is the source code for com.netflix.iep.dynprop.RemoteConfigurationSource.java

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/*
 * Copyright 2015 Netflix, Inc.
 *
 * Licensed 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 com.netflix.iep.dynprop;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Properties;
import java.util.HashMap;

import org.apache.commons.configuration.AbstractConfiguration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.netflix.appinfo.AmazonInfo;
import com.netflix.appinfo.InstanceInfo;
import com.netflix.discovery.DiscoveryClient;

import com.netflix.config.ConfigurationManager;
import com.netflix.config.PollResult;
import com.netflix.config.PolledConfigurationSource;

/**
 * A polled configuration source backed remote service.
 */
public class RemoteConfigurationSource implements PolledConfigurationSource {

    private static final Logger logger = LoggerFactory.getLogger(RemoteConfigurationSource.class);

    private static final String USE_IP = "platformservice.niws.client.UseIpAddress";
    private static final String CONNECT_TIMEOUT = "platformservice.niws.client.ConnectTimeout";
    private static final String READ_TIMEOUT = "platformservice.niws.client.ReadTimeout";
    private static final String NUM_RETRIES = "platformservice.niws.client.MaxAutoRetriesNextServer";
    private static final String VIP = "platformservice.niws.client.DeploymentContextBasedVipAddresses";

    private final InstanceInfo info;
    private final DiscoveryClient client;

    public RemoteConfigurationSource(InstanceInfo info, DiscoveryClient client) {
        this.info = info;
        this.client = client;
    }

    private String getAsgName() {
        return info.getASGName();
    }

    private String getInstanceId() {
        return info.getId();
    }

    private String getZone() {
        return ((AmazonInfo) info.getDataCenterInfo()).get(AmazonInfo.MetaDataKey.availabilityZone);
    }

    private List<String> getHostsForVip(String vip, boolean useIp) {
        List<InstanceInfo> instances = client.getInstancesByVipAddress(vip, false);
        List<String> filtered = new ArrayList<>(instances.size());
        for (InstanceInfo info : instances) {
            if (info.getStatus() == InstanceInfo.InstanceStatus.UP) {
                String host = useIp ? info.getIPAddr() : info.getHostName();
                filtered.add(host + ":" + info.getPort());
            }
        }
        Collections.shuffle(filtered);
        return filtered;
    }

    private Properties getProperties() throws IOException {
        AbstractConfiguration config = ConfigurationManager.getConfigInstance();
        String vip = config.getString(VIP, "atlas_archaius-main:7001");
        List<String> hosts = getHostsForVip(vip, config.getBoolean(USE_IP, false));

        int numAttempts = config.getInt(NUM_RETRIES, 2) + 1;
        for (int i = 1; i <= numAttempts; ++i) {
            String host = hosts.get(i % hosts.size());
            String url = "http://" + host + "/api/v1/property" + "?asg=" + getAsgName() + "&instanceId="
                    + getInstanceId() + "&zone=" + getZone();
            logger.debug("attempt {} of {}, requesting properties from: {}", i, numAttempts, url);

            try {
                URLConnection con = new URL(url).openConnection();
                con.setConnectTimeout(config.getInt(CONNECT_TIMEOUT, 1000));
                con.setReadTimeout(config.getInt(READ_TIMEOUT, 5000));

                Properties props = new Properties();
                try (InputStream in = con.getInputStream()) {
                    props.load(in);
                }

                logger.debug("fetched {} properties from: {}", props.size(), url);
                return props;
            } catch (IOException e) {
                String msg = String.format("attempt %d of %d failed, url: %s", i, numAttempts, url);
                if (i == numAttempts) {
                    logger.error(msg, e);
                    throw e;
                } else {
                    logger.warn(msg, e);
                }
            }
        }

        // Shouldn't get here
        throw new IllegalStateException("failed to get properties");
    }

    @Override
    public PollResult poll(boolean initial, Object checkPoint) throws IOException {

        Properties props = getProperties();
        HashMap<String, Object> mProps = new HashMap<>();
        for (String key : props.stringPropertyNames())
            mProps.put(key, props.getProperty(key));

        PollResult pollResult = PollResult.createFull(mProps);
        if (initial) {
            logger.info("initialized dynamic properties");
        }
        return pollResult;
    }
}