rest-services/http-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RxHttpClient.java

   1 /*
   2  * ============LICENSE_START====================================
   3  * DCAEGEN2-SERVICES-SDK
   4  * =========================================================
   5  * Copyright (C) 2019-2021 Nokia. All rights reserved.
   6  * =========================================================
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *       http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  * ============LICENSE_END=====================================
  19  */
  20
  21 package org.onap.dcaegen2.services.sdk.rest.services.adapters.http;
  22
  23 import io.netty.handler.codec.http.HttpResponseStatus;
  24 import io.vavr.collection.HashSet;
  25 import io.vavr.collection.Stream;
  26 import io.vavr.control.Option;
  27 import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.config.RetryConfig;
  28 import org.onap.dcaegen2.services.sdk.rest.services.model.logging.RequestDiagnosticContext;
  29 import org.slf4j.Logger;
  30 import org.slf4j.LoggerFactory;
  31 import reactor.core.publisher.Flux;
  32 import reactor.core.publisher.Mono;
  33 import reactor.netty.http.client.HttpClient;
  34 import reactor.netty.http.client.HttpClient.ResponseReceiver;
  35 import reactor.netty.http.client.HttpClientRequest;
  36 import reactor.netty.http.client.HttpClientResponse;
  37 import reactor.util.retry.Retry;
  38 import reactor.util.retry.RetryBackoffSpec;
  39
  40 import java.util.stream.Collectors;
  41
  42 /**
  43  * @since 1.1.4
  44  */
  45 public class RxHttpClient {
  46
  47     private static final Logger LOGGER = LoggerFactory.getLogger(RxHttpClient.class);
  48     private final HttpClient httpClient;
  49     private RetryConfig retryConfig;
  50
  51     RxHttpClient(HttpClient httpClient) {
  52         this.httpClient = httpClient;
  53     }
  54
  55     RxHttpClient(HttpClient httpClient, RetryConfig retryConfig) {
  56         this(httpClient);
  57         this.retryConfig = retryConfig;
  58     }
  59
  60     public Mono<HttpResponse> call(HttpRequest request) {
  61         Mono<HttpResponse> httpResponseMono = response(request);
  62         return Option.of(retryConfig)
  63                 .map(rc -> retryConfig(rc, request.diagnosticContext()))
  64                 .map(httpResponseMono::retryWhen)
  65                 .getOrElse(() -> httpResponseMono);
  66     }
  67
  68     ResponseReceiver<?> prepareRequest(HttpRequest request) {
  69         final HttpClient simpleClient = httpClient
  70                 .doOnRequest((req, conn) -> logRequest(request.diagnosticContext(), req))
  71                 .doOnResponse((rsp, conn) -> logResponse(request.diagnosticContext(), rsp))
  72                 .headers(hdrs -> request.headers().forEach(hdr -> hdrs.set(hdr._1, hdr._2)));
  73
  74         final HttpClient theClient = Option.of(request.timeout())
  75                 .map(simpleClient::responseTimeout)
  76                 .getOrElse(simpleClient);
  77
  78         return prepareBody(request, theClient);
  79     }
  80
  81     private Mono<HttpResponse> response(HttpRequest request) {
  82         return prepareRequest(request)
  83                 .responseSingle((resp, content) -> mapResponse(request.url(), resp.status(), content));
  84     }
  85
  86     private Mono<HttpResponse> mapResponse(String url, HttpResponseStatus status, reactor.netty.ByteBufMono content) {
  87         if (shouldRetry(status.code())) {
  88             return Mono.error(new RetryConfig.RetryableException());
  89         }
  90         return content.asByteArray()
  91                 .defaultIfEmpty(new byte[0])
  92                 .map(bytes -> new NettyHttpResponse(url, status, bytes));
  93     }
  94
  95     private boolean shouldRetry(int code) {
  96         return Option.of(retryConfig)
  97                 .map(RetryConfig::retryableHttpResponseCodes)
  98                 .getOrElse(HashSet::empty)
  99                 .contains(code);
 100     }
 101
 102     private ResponseReceiver<?> prepareBody(HttpRequest request, HttpClient theClient) {
 103         if (request.body() == null) {
 104             return prepareBodyWithoutContents(request, theClient);
 105         } else {
 106             return request.body().length() == null
 107                     ? prepareBodyChunked(request, theClient)
 108                     : prepareBodyUnchunked(request, theClient);
 109         }
 110     }
 111
 112     private ResponseReceiver<?> prepareBodyChunked(HttpRequest request, HttpClient theClient) {
 113         return theClient
 114                 .headers(hdrs -> hdrs.set(HttpHeaders.TRANSFER_ENCODING_TYPE, HttpHeaders.CHUNKED))
 115                 .request(request.method().asNetty())
 116                 .send(Flux.from(request.body().contents()))
 117                 .uri(request.url());
 118     }
 119
 120     private ResponseReceiver<?> prepareBodyUnchunked(HttpRequest request, HttpClient theClient) {
 121         return theClient
 122                 .headers(hdrs -> hdrs.set(HttpHeaders.CONTENT_LENGTH, request.body().length().toString()))
 123                 .request(request.method().asNetty())
 124                 .send(Flux.from(request.body().contents()))
 125                 .uri(request.url());
 126     }
 127
 128     private ResponseReceiver<?> prepareBodyWithoutContents(HttpRequest request, HttpClient theClient) {
 129         return theClient
 130                 .request(request.method().asNetty())
 131                 .uri(request.url());
 132     }
 133
 134     private void logRequest(RequestDiagnosticContext context, HttpClientRequest httpClientRequest) {
 135         context.withSlf4jMdc(LOGGER.isDebugEnabled(), () -> {
 136             LOGGER.debug("Request: {} {} {}", httpClientRequest.method(), httpClientRequest.uri(),
 137                     httpClientRequest.requestHeaders());
 138             if (LOGGER.isTraceEnabled()) {
 139                 final String headers = Stream.ofAll(httpClientRequest.requestHeaders())
 140                         .map(entry -> entry.getKey() + "=" + entry.getValue())
 141                         .collect(Collectors.joining("\n"));
 142                 LOGGER.trace(headers);
 143             }
 144         });
 145     }
 146
 147     private void logResponse(RequestDiagnosticContext context, HttpClientResponse httpClientResponse) {
 148         context.withSlf4jMdc(LOGGER.isDebugEnabled(),
 149                 () -> LOGGER.debug("Response status: {}", httpClientResponse.status()));
 150     }
 151
 152     private RetryBackoffSpec retryConfig(RetryConfig retryConfig, RequestDiagnosticContext context) {
 153         RetryBackoffSpec retry = Retry
 154                 .fixedDelay(retryConfig.retryCount(), retryConfig.retryInterval())
 155                 .doBeforeRetry(retrySignal -> context.withSlf4jMdc(
 156                         LOGGER.isTraceEnabled(), () -> LOGGER.trace("Retry: {}", retrySignal)))
 157                 .filter(ex -> isRetryable(retryConfig, ex));
 158
 159         return Option.of(retryConfig.onRetryExhaustedException())
 160                 .map(ex -> retry.onRetryExhaustedThrow((retryBackoffSpec, retrySignal) -> ex))
 161                 .getOrElse(retry);
 162     }
 163
 164     private boolean isRetryable(RetryConfig retryConfig, Throwable ex) {
 165         return retryConfig.retryableExceptions()
 166                 .toStream()
 167                 .exists(clazz -> clazz.isAssignableFrom(ex.getClass()));
 168     }
 169 }