org.apache.tamaya.etcd.EtcdPropertySource Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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.apache.tamaya.etcd;
import org.apache.tamaya.mutableconfig.propertysources.AbstractMutablePropertySource;
import org.apache.tamaya.mutableconfig.propertysources.ConfigChangeContext;
import org.apache.tamaya.spi.PropertyValue;
import org.apache.tamaya.spi.PropertyValueBuilder;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Propertysource that is reading configuration from a configured etcd endpoint. Setting
* {@code etcd.prefix} as system property maps the etcd based onfiguration
* to this prefix namespace. Etcd servers are configured as {@code etcd.server.urls} system or environment property.
* ETcd can be disabled by setting {@code tamaya.etcdprops.disable} either as env or system property.
*/
public class EtcdPropertySource extends AbstractMutablePropertySource{
private static final Logger LOG = Logger.getLogger(EtcdPropertySource.class.getName());
private String prefix = System.getProperty("tamaya.etcd.prefix", "");
private final boolean disabled = evaluateDisabled();
private boolean evaluateDisabled() {
String value = System.getProperty("tamaya.etcdprops.disable");
if(value==null){
value = System.getenv("tamaya.etcdprops.disable");
}
if(value==null){
return false;
}
return value.isEmpty() || Boolean.parseBoolean(value);
}
@Override
public int getOrdinal() {
PropertyValue configuredOrdinal = get(TAMAYA_ORDINAL);
if(configuredOrdinal!=null){
try{
return Integer.parseInt(configuredOrdinal.getValue());
} catch(Exception e){
Logger.getLogger(getClass().getName()).log(Level.WARNING,
"Configured Ordinal is not an int number: " + configuredOrdinal, e);
}
}
return getDefaultOrdinal();
}
/**
* Returns the default ordinal used, when no ordinal is set, or the ordinal was not parseable to an int value.
* @return the default ordinal used, by default 0.
*/
public int getDefaultOrdinal(){
return 1000;
}
@Override
public String getName() {
return "etcd";
}
@Override
public PropertyValue get(String key) {
if(disabled){
return null;
}
// check prefix, if key does not start with it, it is not part of our name space
// if so, the prefix part must be removedProperties, so etcd can resolve without it
if(!key.startsWith(prefix)){
return null;
} else{
key = key.substring(prefix.length());
}
Map props;
String reqKey = key;
if(key.startsWith("_")){
reqKey = key.substring(1);
if(reqKey.endsWith(".createdIndex")){
reqKey = reqKey.substring(0,reqKey.length()-".createdIndex".length());
} else if(reqKey.endsWith(".modifiedIndex")){
reqKey = reqKey.substring(0,reqKey.length()-".modifiedIndex".length());
} else if(reqKey.endsWith(".ttl")){
reqKey = reqKey.substring(0,reqKey.length()-".ttl".length());
} else if(reqKey.endsWith(".expiration")){
reqKey = reqKey.substring(0,reqKey.length()-".expiration".length());
} else if(reqKey.endsWith(".source")){
reqKey = reqKey.substring(0,reqKey.length()-".source".length());
}
}
for(EtcdAccessor accessor: EtcdBackends.getEtcdBackends()){
try{
props = accessor.get(reqKey);
if(!props.containsKey("_ERROR")) {
// No repfix mapping necessary here, since we only access/return the value...
return new PropertyValueBuilder(key, props.get(reqKey), getName()).setContextData(props).build();
} else{
LOG.log(Level.FINE, "etcd error on " + accessor.getUrl() + ": " + props.get("_ERROR"));
}
} catch(Exception e){
LOG.log(Level.FINE, "etcd access failed on " + accessor.getUrl() + ", trying next...", e);
}
}
return null;
}
@Override
public Map getProperties() {
if(disabled){
return Collections.emptyMap();
}
if(!EtcdBackends.getEtcdBackends().isEmpty()){
for(EtcdAccessor accessor: EtcdBackends.getEtcdBackends()){
try{
Map props = accessor.getProperties("");
if(!props.containsKey("_ERROR")) {
return mapPrefix(props);
} else{
LOG.log(Level.FINE, "etcd error on " + accessor.getUrl() + ": " + props.get("_ERROR"));
}
} catch(Exception e){
LOG.log(Level.FINE, "etcd access failed on " + accessor.getUrl() + ", trying next...", e);
}
}
}
return Collections.emptyMap();
}
private Map mapPrefix(Map props) {
if(prefix.isEmpty()){
return props;
}
Map map = new HashMap<>();
for(Map.Entry entry:props.entrySet()){
if(entry.getKey().startsWith("_")){
map.put("_" + prefix + entry.getKey().substring(1), entry.getValue());
} else{
map.put(prefix+ entry.getKey(), entry.getValue());
}
}
return map;
}
@Override
public boolean isScannable() {
return true;
}
@Override
protected void commitInternal(ConfigChangeContext context) {
for(EtcdAccessor accessor: EtcdBackends.getEtcdBackends()){
try{
for(String k: context.getRemovedProperties()){
Map res = accessor.delete(k);
if(res.get("_ERROR")!=null){
LOG.info("Failed to remove key from etcd: " + k);
}
}
for(Map.Entry en:context.getAddedProperties().entrySet()){
String key = en.getKey();
Integer ttl = null;
int index = en.getKey().indexOf('?');
if(index>0){
key = en.getKey().substring(0, index);
String rawQuery = en.getKey().substring(index+1);
String[] queries = rawQuery.split("&");
for(String query:queries){
if(query.contains("ttl")){
int qIdx = query.indexOf('=');
ttl = qIdx>0?Integer.parseInt(query.substring(qIdx+1).trim()):null;
}
}
}
Map res = accessor.set(key, en.getValue(), ttl);
if(res.get("_ERROR")!=null){
LOG.info("Failed to add key to etcd: " + en.getKey() + "=" + en.getValue());
}
}
// success, stop here
break;
} catch(Exception e){
LOG.log(Level.FINE, "etcd access failed on " + accessor.getUrl() + ", trying next...", e);
}
}
}
}
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