org.springframework.cloud.sleuth.zipkin2.sender.ZipkinRestTemplateSenderConfiguration.java Source code

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Here is the source code for org.springframework.cloud.sleuth.zipkin2.sender.ZipkinRestTemplateSenderConfiguration.java

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/*
 * Copyright 2013-2018 the original author or authors.
 *
 * 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 org.springframework.cloud.sleuth.zipkin2.sender;

import java.net.URI;
import java.net.URISyntaxException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.cloud.sleuth.zipkin2.ZipkinLoadBalancer;
import org.springframework.cloud.sleuth.zipkin2.ZipkinProperties;
import org.springframework.cloud.sleuth.zipkin2.ZipkinRestTemplateCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Conditional;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpMethod;
import org.springframework.web.client.RequestCallback;
import org.springframework.web.client.ResponseExtractor;
import org.springframework.web.client.RestClientException;
import org.springframework.web.client.RestTemplate;
import zipkin2.reporter.Sender;

@Configuration
@ConditionalOnMissingBean(Sender.class)
@Conditional(ZipkinSenderCondition.class)
@EnableConfigurationProperties(ZipkinSenderProperties.class)
class ZipkinRestTemplateSenderConfiguration {

    @Autowired
    ZipkinUrlExtractor extractor;

    @Bean
    @ConditionalOnMissingBean
    public Sender restTemplateSender(ZipkinProperties zipkin,
            ZipkinRestTemplateCustomizer zipkinRestTemplateCustomizer) {
        RestTemplate restTemplate = new ZipkinRestTemplateWrapper(zipkin, this.extractor);
        zipkinRestTemplateCustomizer.customize(restTemplate);
        return new RestTemplateSender(restTemplate, zipkin.getBaseUrl(), zipkin.getEncoder());
    }

    @Configuration
    @ConditionalOnMissingClass("org.springframework.cloud.client.loadbalancer.LoadBalancerClient")
    static class DefaultZipkinUrlExtractorConfiguration {

        @Autowired(required = false)
        LoadBalancerClient client;

        @Bean
        @ConditionalOnMissingBean
        ZipkinLoadBalancer noOpLoadBalancer(final ZipkinProperties zipkinProperties) {
            return new NoOpZipkinLoadBalancer(zipkinProperties);
        }

    }

    @Configuration
    @ConditionalOnClass(LoadBalancerClient.class)
    static class DiscoveryClientZipkinUrlExtractorConfiguration {

        @Configuration
        @ConditionalOnProperty(value = "spring.zipkin.discoveryClientEnabled", havingValue = "true", matchIfMissing = true)
        static class ZipkinClientLoadBalancedConfiguration {

            @Autowired(required = false)
            LoadBalancerClient client;

            @Bean
            @ConditionalOnMissingBean
            ZipkinLoadBalancer loadBalancerClientZipkinLoadBalancer(ZipkinProperties zipkinProperties) {
                return new LoadBalancerClientZipkinLoadBalancer(this.client, zipkinProperties);
            }

        }

        @Configuration
        @ConditionalOnProperty(value = "spring.zipkin.discoveryClientEnabled", havingValue = "false")
        static class ZipkinClientNoOpConfiguration {

            @Bean
            @ConditionalOnMissingBean
            ZipkinLoadBalancer noOpLoadBalancer(final ZipkinProperties zipkinProperties) {
                return new NoOpZipkinLoadBalancer(zipkinProperties);
            }

        }

    }

    @Bean
    ZipkinUrlExtractor zipkinUrlExtractor(final ZipkinLoadBalancer zipkinLoadBalancer) {
        return new ZipkinUrlExtractor() {
            @Override
            public URI zipkinUrl(ZipkinProperties zipkinProperties) {
                return zipkinLoadBalancer.instance();
            }
        };
    }

}

/**
 * Resolves at runtime where the Zipkin server is. If there's no discovery client then
 * {@link URI} from the properties is taken. Otherwise service discovery is pinged for
 * current Zipkin address.
 */
class ZipkinRestTemplateWrapper extends RestTemplate {

    private static final Log log = LogFactory.getLog(ZipkinRestTemplateWrapper.class);

    private final ZipkinProperties zipkinProperties;

    private final ZipkinUrlExtractor extractor;

    ZipkinRestTemplateWrapper(ZipkinProperties zipkinProperties, ZipkinUrlExtractor extractor) {
        this.zipkinProperties = zipkinProperties;
        this.extractor = extractor;
    }

    @Override
    protected <T> T doExecute(URI originalUrl, HttpMethod method, RequestCallback requestCallback,
            ResponseExtractor<T> responseExtractor) throws RestClientException {
        URI uri = this.extractor.zipkinUrl(this.zipkinProperties);
        URI newUri = resolvedZipkinUri(originalUrl, uri);
        return super.doExecute(newUri, method, requestCallback, responseExtractor);
    }

    private URI resolvedZipkinUri(URI originalUrl, URI resolvedZipkinUri) {
        try {
            return new URI(resolvedZipkinUri.getScheme(), resolvedZipkinUri.getUserInfo(),
                    resolvedZipkinUri.getHost(), resolvedZipkinUri.getPort(), originalUrl.getPath(),
                    originalUrl.getQuery(), originalUrl.getFragment());
        } catch (URISyntaxException e) {
            if (log.isDebugEnabled()) {
                log.debug("Failed to create the new URI from original [" + originalUrl + "] and new one ["
                        + resolvedZipkinUri + "]");
            }
            return originalUrl;
        }
    }

}

/**
 * Internal interface to provide a way to retrieve Zipkin URI. If there's no discovery
 * client then this value will be taken from the properties. Otherwise host will be
 * assumed to be a service id.
 */
interface ZipkinUrlExtractor {

    URI zipkinUrl(ZipkinProperties zipkinProperties);

}

class NoOpZipkinLoadBalancer implements ZipkinLoadBalancer {

    private final ZipkinProperties zipkinProperties;

    NoOpZipkinLoadBalancer(ZipkinProperties zipkinProperties) {
        this.zipkinProperties = zipkinProperties;
    }

    @Override
    public URI instance() {
        return URI.create(this.zipkinProperties.getBaseUrl());
    }

}