Java tutorial
/* * Copyright 2016 EPAM Systems * * * This file is part of EPAM Report Portal. * https://github.com/reportportal/service-gateway * * Report Portal is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * Report Portal is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with Report Portal. If not, see <http://www.gnu.org/licenses/>. */ package com.epam.reportportal.gateway; import com.google.common.base.Supplier; import com.google.common.base.Suppliers; import com.netflix.appinfo.InstanceInfo; import com.netflix.discovery.EurekaClient; import org.apache.http.impl.client.HttpClientBuilder; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.cloud.client.ServiceInstance; import org.springframework.cloud.client.discovery.DiscoveryClient; import org.springframework.http.HttpEntity; import org.springframework.http.HttpHeaders; import org.springframework.http.HttpMethod; import org.springframework.http.MediaType; import org.springframework.http.client.HttpComponentsClientHttpRequestFactory; import org.springframework.web.bind.annotation.*; import org.springframework.web.client.RestTemplate; import java.util.*; import java.util.concurrent.TimeUnit; import java.util.function.Function; import java.util.stream.Collectors; import static java.util.stream.Collectors.toMap; /** * Shares information about component versions * * @author Andrei Varabyeu */ @RestController public class CompositeInfoEndpoint { private static final Logger LOGGER = LoggerFactory.getLogger(CompositeInfoEndpoint.class); private static final String EXTENSION_KEY = "extension"; private final DiscoveryClient discoveryClient; private final EurekaClient eurekaClient; private final RestTemplate loadBalancedRestTemplate; private final RestTemplate restTemplate; /* Simple cache for 2 minutes to avoid calling to all services */ private final Supplier<Map<String, ?>> servicesInfos = Suppliers.memoizeWithExpiration(this::composeInfo, 2, TimeUnit.MINUTES); @SuppressWarnings("SpringJavaAutowiringInspection") @Autowired public CompositeInfoEndpoint(RestTemplate loadBalancedRestTemplate, DiscoveryClient discoveryClient, EurekaClient eurekaClient) { this.restTemplate = new RestTemplate(new HttpComponentsClientHttpRequestFactory( HttpClientBuilder.create().setSSLHostnameVerifier((s, sslSession) -> true).build())); this.loadBalancedRestTemplate = loadBalancedRestTemplate; this.discoveryClient = discoveryClient; this.eurekaClient = eurekaClient; } @RequestMapping(value = "/composite/{endpoint}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_UTF8_VALUE) @ResponseBody public Map<String, ?> compose(@PathVariable("endpoint") String endpoint) { return discoveryClient.getServices().stream() .map((Function<String, AbstractMap.SimpleImmutableEntry<String, Object>>) service -> { try { List<ServiceInstance> instances = discoveryClient.getInstances(service); if (instances.isEmpty()) { return new AbstractMap.SimpleImmutableEntry<>(service, "DOWN"); } ServiceInstance instance = instances.get(0); String protocol = instance.isSecure() ? "https" : "http"; HttpHeaders headers = new HttpHeaders(); headers.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON)); return new AbstractMap.SimpleImmutableEntry<>(instance.getServiceId(), loadBalancedRestTemplate.exchange(protocol + "://{service}/{endpoint}", HttpMethod.GET, new HttpEntity<>(null, headers), Map.class, instance.getServiceId(), endpoint).getBody()); } catch (Exception e) { return new AbstractMap.SimpleImmutableEntry<>(service, "DOWN"); } }).collect(toMap(AbstractMap.SimpleImmutableEntry::getKey, AbstractMap.SimpleImmutableEntry::getValue, (value1, value2) -> value2)); } @RequestMapping(value = "/composite/info", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_UTF8_VALUE) @ResponseBody public Map<String, ?> composeInfos() { return servicesInfos.get(); } @RequestMapping(value = "/composite/health", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_UTF8_VALUE) @ResponseBody public Map<String, ?> composeHealth() { return eurekaClient.getApplications().getRegisteredApplications().stream() .flatMap(app -> app.getInstances().stream()) .collect(Collectors.toMap(InstanceInfo::getAppName, InstanceInfo::getStatus)); } private Map<String, ?> composeInfo() { return eurekaClient.getApplications().getRegisteredApplications().stream() .flatMap(app -> app.getInstances().stream()).map(instanceInfo -> { try { HttpHeaders headers = new HttpHeaders(); headers.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON)); return new AbstractMap.SimpleImmutableEntry<>(instanceInfo.getAppName(), restTemplate.exchange(instanceInfo.getStatusPageUrl(), HttpMethod.GET, new HttpEntity<>(null, headers), Map.class).getBody()); } catch (Exception e) { LOGGER.error("Unable to obtain service info", e); return new AbstractMap.SimpleImmutableEntry<>(instanceInfo.getAppName(), "DOWN"); } }).collect(toMap(AbstractMap.SimpleImmutableEntry::getKey, AbstractMap.SimpleImmutableEntry::getValue, (value1, value2) -> value2)); } }