pmproducer/src/main/java/org/oran/pmproducer/clients/AsyncRestClient.java

   1 /*-
   2  * ========================LICENSE_START=================================
   3  * O-RAN-SC
   4  * %%
   5  * Copyright (C) 2023 Nordix Foundation
   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.oran.pmproducer.clients;
  22
  23 import io.netty.channel.ChannelOption;
  24 import io.netty.handler.ssl.SslContext;
  25 import io.netty.handler.timeout.ReadTimeoutHandler;
  26 import io.netty.handler.timeout.WriteTimeoutHandler;
  27
  28 import java.lang.invoke.MethodHandles;
  29 import java.util.concurrent.atomic.AtomicInteger;
  30
  31 import org.oran.pmproducer.configuration.WebClientConfig.HttpProxyConfig;
  32 import org.oran.pmproducer.oauth2.SecurityContext;
  33 import org.slf4j.Logger;
  34 import org.slf4j.LoggerFactory;
  35 import org.springframework.http.MediaType;
  36 import org.springframework.http.ResponseEntity;
  37 import org.springframework.http.client.reactive.ReactorClientHttpConnector;
  38 import org.springframework.lang.Nullable;
  39 import org.springframework.web.reactive.function.client.ExchangeFilterFunction;
  40 import org.springframework.web.reactive.function.client.ExchangeStrategies;
  41 import org.springframework.web.reactive.function.client.WebClient;
  42 import org.springframework.web.reactive.function.client.WebClient.RequestHeadersSpec;
  43 import org.springframework.web.reactive.function.client.WebClientResponseException;
  44
  45 import reactor.core.publisher.Mono;
  46 import reactor.netty.http.client.HttpClient;
  47 import reactor.netty.transport.ProxyProvider;
  48
  49 /**
  50  * Generic reactive REST client.
  51  */
  52 public class AsyncRestClient {
  53
  54     private static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
  55     private WebClient webClient = null;
  56     private final String baseUrl;
  57     private static final AtomicInteger sequenceNumber = new AtomicInteger();
  58     private final SslContext sslContext;
  59     private final HttpProxyConfig httpProxyConfig;
  60     private final SecurityContext securityContext;
  61
  62     public AsyncRestClient(String baseUrl, @Nullable SslContext sslContext, @Nullable HttpProxyConfig httpProxyConfig,
  63             SecurityContext securityContext) {
  64         this.baseUrl = baseUrl;
  65         this.sslContext = sslContext;
  66         this.httpProxyConfig = httpProxyConfig;
  67         this.securityContext = securityContext;
  68     }
  69
  70     @SuppressWarnings("java:S4449") // contentType, is not @Nullable
  71     public Mono<ResponseEntity<String>> postForEntity(String uri, @Nullable String body,
  72             @Nullable MediaType mediaType) {
  73         Mono<String> bodyProducer = body != null ? Mono.just(body) : Mono.empty();
  74
  75         RequestHeadersSpec<?> request = getWebClient() //
  76                 .post() //
  77                 .uri(uri) //
  78                 .contentType(mediaType) //
  79                 .body(bodyProducer, String.class);
  80         return retrieve(request);
  81     }
  82
  83     public Mono<String> post(String uri, @Nullable String body, @Nullable MediaType mediaType) {
  84         return postForEntity(uri, body, mediaType) //
  85                 .map(this::toBody);
  86     }
  87
  88     public Mono<ResponseEntity<String>> putForEntity(String uri, String body) {
  89         RequestHeadersSpec<?> request = getWebClient() //
  90                 .put() //
  91                 .uri(uri) //
  92                 .contentType(MediaType.APPLICATION_JSON) //
  93                 .bodyValue(body);
  94         return retrieve(request);
  95     }
  96
  97     public Mono<String> put(String uri, String body) {
  98         return putForEntity(uri, body) //
  99                 .map(this::toBody);
 100     }
 101
 102     public Mono<ResponseEntity<String>> getForEntity(String uri) {
 103         RequestHeadersSpec<?> request = getWebClient().get().uri(uri);
 104         return retrieve(request);
 105     }
 106
 107     public Mono<String> get(String uri) {
 108         return getForEntity(uri) //
 109                 .map(this::toBody);
 110     }
 111
 112     public Mono<ResponseEntity<String>> deleteForEntity(String uri) {
 113         RequestHeadersSpec<?> request = getWebClient().delete().uri(uri);
 114         return retrieve(request);
 115     }
 116
 117     public Mono<String> delete(String uri) {
 118         return deleteForEntity(uri) //
 119                 .map(this::toBody);
 120     }
 121
 122     public Mono<ResponseEntity<String>> postForEntity(String uri, @Nullable String body) {
 123         Mono<String> bodyProducer = body != null ? Mono.just(body) : Mono.empty();
 124
 125         RequestHeadersSpec<?> request = getWebClient() //
 126                 .post() //
 127                 .uri(uri) //
 128                 .contentType(MediaType.APPLICATION_JSON) //
 129                 .body(bodyProducer, String.class);
 130         return retrieve(request);
 131     }
 132
 133     public Mono<String> post(String uri, @Nullable String body) {
 134         return postForEntity(uri, body) //
 135                 .map(this::toBody);
 136     }
 137
 138     private Mono<ResponseEntity<String>> retrieve(RequestHeadersSpec<?> request) {
 139         if (securityContext.isConfigured()) {
 140             request.headers(h -> h.setBearerAuth(securityContext.getBearerAuthToken()));
 141         }
 142         return request.retrieve() //
 143                 .toEntity(String.class) //
 144                 .doOnError(this::onError); //
 145     }
 146
 147     private void onError(Throwable t) {
 148         if (t instanceof WebClientResponseException) {
 149             WebClientResponseException e = (WebClientResponseException) t;
 150             logger.debug("Response error: {}", e.getResponseBodyAsString());
 151         }
 152     }
 153
 154     private static Object createTraceTag() {
 155         return sequenceNumber.incrementAndGet();
 156     }
 157
 158     private String toBody(ResponseEntity<String> entity) {
 159         if (entity.getBody() == null) {
 160             return "";
 161         } else {
 162             return entity.getBody();
 163         }
 164     }
 165
 166     private boolean isHttpProxyConfigured() {
 167         return httpProxyConfig != null && httpProxyConfig.getHttpProxyPort() > 0
 168                 && !httpProxyConfig.getHttpProxyHost().isEmpty();
 169     }
 170
 171     private HttpClient buildHttpClient() {
 172         HttpClient httpClient = HttpClient.create() //
 173                 .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 10_000) //
 174                 .doOnConnected(connection -> {
 175                     connection.addHandlerLast(new ReadTimeoutHandler(30));
 176                     connection.addHandlerLast(new WriteTimeoutHandler(30));
 177                 });
 178
 179         if (this.sslContext != null) {
 180             httpClient = httpClient.secure(ssl -> ssl.sslContext(sslContext));
 181         }
 182
 183         if (isHttpProxyConfigured()) {
 184             httpClient = httpClient.proxy(proxy -> proxy.type(ProxyProvider.Proxy.HTTP)
 185                     .host(httpProxyConfig.getHttpProxyHost()).port(httpProxyConfig.getHttpProxyPort()));
 186         }
 187         return httpClient;
 188     }
 189
 190     public WebClient buildWebClient(String baseUrl) {
 191         Object traceTag = createTraceTag();
 192
 193         final HttpClient httpClient = buildHttpClient();
 194         ExchangeStrategies exchangeStrategies = ExchangeStrategies.builder() //
 195                 .codecs(configurer -> configurer.defaultCodecs().maxInMemorySize(-1)) //
 196                 .build();
 197
 198         ExchangeFilterFunction reqLogger = ExchangeFilterFunction.ofRequestProcessor(req -> {
 199             logger.debug("{} {} uri = '{}''", traceTag, req.method(), req.url());
 200             return Mono.just(req);
 201         });
 202
 203         ExchangeFilterFunction respLogger = ExchangeFilterFunction.ofResponseProcessor(resp -> {
 204             logger.debug("{} resp: {}", traceTag, resp.statusCode());
 205             return Mono.just(resp);
 206         });
 207
 208         return WebClient.builder() //
 209                 .clientConnector(new ReactorClientHttpConnector(httpClient)) //
 210                 .baseUrl(baseUrl) //
 211                 .exchangeStrategies(exchangeStrategies) //
 212                 .filter(reqLogger) //
 213                 .filter(respLogger) //
 214                 .build();
 215     }
 216
 217     private WebClient getWebClient() {
 218         if (this.webClient == null) {
 219             this.webClient = buildWebClient(baseUrl);
 220         }
 221         return this.webClient;
 222     }
 223 }