org.zodiac.loadbalancer.ribbon.predicate.MetadataAwarePredicate Maven / Gradle / Ivy

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package org.zodiac.loadbalancer.ribbon.predicate;

import org.zodiac.commons.support.SpringContextHolder;
import org.zodiac.core.application.AppContext;
import org.zodiac.core.bootstrap.discovery.AppDiscoveryStrategyInfo;
import org.zodiac.core.bootstrap.discovery.SameTagPreferredStrategy;
import org.zodiac.loadbalancer.common.constants.LoadBalancerConstants;
import org.zodiac.loadbalancer.ribbon.config.PlatformRibbonRuleInfo;
import org.zodiac.sdk.toolkit.util.lang.StrUtil;

import com.netflix.client.config.IClientConfig;
import com.netflix.loadbalancer.IRule;
import com.netflix.loadbalancer.LoadBalancerStats;

import java.util.Map;

/**
 * 基于 Metadata 的服务筛选。
 *
 */
public class MetadataAwarePredicate extends DiscoveryEnabledPredicate {

    @Deprecated
    public static final MetadataAwarePredicate DEFAULT_INSTANCE = new MetadataAwarePredicate();

    private AppDiscoveryStrategyInfo discoveryStrategyInfo;
    private PlatformRibbonRuleInfo platfromRibbonRule;

    @Deprecated
    public MetadataAwarePredicate() {
        this(null);
    }

    public MetadataAwarePredicate(AppDiscoveryStrategyInfo discoveryStrategyInfo) {
        this.discoveryStrategyInfo = discoveryStrategyInfo;
    }

    public MetadataAwarePredicate(AppDiscoveryStrategyInfo discoveryStrategyInfo, PlatformRibbonRuleInfo platfromRibbonRule) {
        super();
        this.platfromRibbonRule = platfromRibbonRule;
        this.discoveryStrategyInfo = discoveryStrategyInfo;
    }

    public MetadataAwarePredicate(IRule rule, IClientConfig clientConfig, AppDiscoveryStrategyInfo discoveryStrategyInfo, PlatformRibbonRuleInfo platfromRibbonRule) {
        super(rule, clientConfig);
        this.platfromRibbonRule = platfromRibbonRule;
    }

    public MetadataAwarePredicate(IRule rule, AppDiscoveryStrategyInfo discoveryStrategyInfo, PlatformRibbonRuleInfo platfromRibbonRule) {
        this(rule, null, discoveryStrategyInfo, platfromRibbonRule);
    }

    public MetadataAwarePredicate(LoadBalancerStats lbStats, IClientConfig clientConfig, AppDiscoveryStrategyInfo discoveryStrategyInfo, PlatformRibbonRuleInfo platfromRibbonRule) {
        super(lbStats, clientConfig);
        this.discoveryStrategyInfo = discoveryStrategyInfo;
        this.platfromRibbonRule = platfromRibbonRule;
    }

    public PlatformRibbonRuleInfo getPlatfromRibbonRoutingInfo() {
        return platfromRibbonRule;
    }

    @Override
    protected void init() {
        if (null == this.platfromRibbonRule) {
            this.platfromRibbonRule = SpringContextHolder.getBean(PlatformRibbonRuleInfo.class);
        }
    }

    @Override
    protected boolean apply(MetadataServer server) {
        /*服务里的配置。*/
        String localTag = platfromRibbonRule.getTag();
        if (StrUtil.isBlank(localTag)) {
            return true;
        }
        Map metadata = server.getMetadata();
        /*本地有 tag，服务没有，返回 false。*/
        String metaDataTag = metadata.get(LoadBalancerConstants.LOAD_BALANCER_TAG_KEY);
        if (StrUtil.isBlank(metaDataTag)) {
            /*如果统一发现策略存在，则尝试使用。*/
            if (null != discoveryStrategyInfo && discoveryStrategyInfo.isEnabled()) {
                SameTagPreferredStrategy sameTagPreferredStrategy = discoveryStrategyInfo.getSameTagPreferred();
                if (sameTagPreferredStrategy.isLocalTagEnabled()) {
                    /*如果开启了local tag，则尝试使用。*/
                    Map instanceMetadata = obtainInstanceMetadata();
                    localTag = instanceMetadata.get(sameTagPreferredStrategy.getDefaultTagKey());
                }
            }
        }
        if (StrUtil.isBlank(metaDataTag)) {
            return false;
        }
        return metaDataTag.equals(localTag);
    }

    protected Map obtainInstanceMetadata() {
        return AppContext.getInstance().getAppMetadata();
    }

}