com.alibaba.nacos.naming.selector.LabelSelector Maven / Gradle / Ivy
/*
* Copyright 1999-2021 Alibaba Group Holding Ltd.
*
* 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.alibaba.nacos.naming.selector;
import com.alibaba.nacos.api.cmdb.pojo.Entity;
import com.alibaba.nacos.api.exception.NacosException;
import com.alibaba.nacos.api.naming.pojo.Instance;
import com.alibaba.nacos.api.selector.AbstractCmdbSelector;
import com.alibaba.nacos.api.selector.context.CmdbContext;
import com.alibaba.nacos.common.utils.CollectionUtils;
import com.alibaba.nacos.common.utils.StringUtils;
import com.alibaba.nacos.naming.selector.interpreter.ExpressionInterpreter;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.Set;
import java.util.stream.Collectors;
/**
* The {@link LabelSelector} will return the instances labels in {@link #labels} and providers' label value is same with consumer.
* If none matched, then will return all providers instead of.
*
* @author chenglu
* @date 2021-07-16 16:26
*/
public class LabelSelector extends AbstractCmdbSelector {
private static final String TYPE = "label";
/**
* {@link Entity} labels key.
*/
private Set labels;
public Set getLabels() {
return labels;
}
public void setLabels(Set labels) {
this.labels = labels;
}
@Override
protected List doSelect(CmdbContext context) {
if (CollectionUtils.isEmpty(labels)) {
return context.getProviders()
.stream()
.map(CmdbContext.CmdbInstance::getInstance)
.collect(Collectors.toList());
}
CmdbContext.CmdbInstance consumer = context.getConsumer();
Map consumerLabels = Optional.ofNullable(consumer.getEntity())
.map(Entity::getLabels)
.orElse(Collections.emptyMap());
// filter the instance if consumer and providers' label values equals.
List result = context.getProviders()
.stream()
.filter(ci -> {
Entity providerEntity = ci.getEntity();
if (Objects.isNull(providerEntity)) {
return false;
}
Map providerLabels = Optional.ofNullable(ci.getEntity().getLabels())
.orElse(Collections.emptyMap());
return labels.stream()
.allMatch(label -> {
String consumerLabelValue = consumerLabels.get(label);
if (StringUtils.isBlank(consumerLabelValue)) {
return false;
}
return Objects.equals(consumerLabelValue, providerLabels.get(label));
});
})
.map(CmdbContext.CmdbInstance::getInstance)
.collect(Collectors.toList());
// if none match, then return all providers.
if (CollectionUtils.isEmpty(result)) {
return context.getProviders()
.stream()
.map(CmdbContext.CmdbInstance::getInstance)
.collect(Collectors.toList());
}
return result;
}
@Override
protected void doParse(String expression) throws NacosException {
this.labels = ExpressionInterpreter.parseExpression(expression);
}
@Override
public String getType() {
return TYPE;
}
}