com.predic8.membrane.core.cloud.etcd.EtcdResolver Maven / Gradle / Ivy
/*
* Copyright 2015 predic8 GmbH, www.predic8.com
* 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.predic8.membrane.core.cloud.etcd;
import com.google.common.collect.Lists;
import com.predic8.membrane.annot.MCAttribute;
import com.predic8.membrane.annot.MCElement;
import com.predic8.membrane.core.util.functionalInterfaces.ExceptionThrowingConsumer;
import com.predic8.membrane.core.resolver.ResourceRetrievalException;
import com.predic8.membrane.core.resolver.SchemaResolver;
import java.io.ByteArrayInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.util.HashSet;
import java.util.List;
import java.util.regex.Matcher;
@MCElement(name="etcdResolver")
public class EtcdResolver implements SchemaResolver{
private String url;
HashSet etcdWatchThreads = new HashSet<>();
public String getUrl() {
return url;
}
@MCAttribute
public void setUrl(String url) {
this.url = url;
}
@Override
public List getSchemas() {
return Lists.newArrayList("etcd");
}
@Override
public InputStream resolve(String url) throws ResourceRetrievalException {
String normalizedUrl = normalize(url);
if(normalizedUrl.startsWith("etcd://")){
// we keep the last slash
normalizedUrl = normalizedUrl.substring(6);
}
int lastSlash = normalizedUrl.lastIndexOf("/");
String baseKey = normalizedUrl.substring(0,lastSlash);
String valueName = normalizedUrl.substring(lastSlash+1);
EtcdResponse respGetValue = EtcdRequest.create(this.url,baseKey,"").getValue(valueName).sendRequest();
if(!respGetValue.is2XX()) {
throw new ResourceRetrievalException(url);
}
String value = respGetValue.getValue();
return new ByteArrayInputStream(value.getBytes());
}
private String normalize(String url) {
return url.replaceAll(Matcher.quoteReplacement("\\"),"/");
}
@Override
public void observeChange(final String url, final ExceptionThrowingConsumer consumer) throws ResourceRetrievalException {
final Thread etcdWatcher = new Thread(() -> {
String normalizedUrl = normalize(url);
if(normalizedUrl.startsWith("etcd://")){
// we keep the last slash
normalizedUrl = normalizedUrl.substring(6);
}
int lastSlash = normalizedUrl.lastIndexOf("/");
String baseKey = normalizedUrl.substring(0,lastSlash);
String valueName = normalizedUrl.substring(lastSlash+1,normalizedUrl.length());
EtcdResponse respLongPollForChange = EtcdRequest.create(EtcdResolver.this.url,baseKey,"").getValue(valueName).longPoll().sendRequest();
if(!respLongPollForChange.is2XX()){
}
try {
consumer.accept(resolve(normalizedUrl));
} catch (Exception ignored) {
}
synchronized (etcdWatchThreads) {
etcdWatchThreads.remove(Thread.currentThread());
}
});
synchronized (etcdWatchThreads) {
etcdWatchThreads.add(etcdWatcher);
}
etcdWatcher.start();
}
@Override
public List getChildren(String url) throws FileNotFoundException {
return null;
}
@Override
public long getTimestamp(String url) throws FileNotFoundException {
return 0;
}
}