dmaap-adaptor-java/src/main/java/org/oran/dmaapadapter/clients/AsyncRestClient.java

   1 /*-
   2  * ========================LICENSE_START=================================
   3  * O-RAN-SC
   4  * %%
   5  * Copyright (C) 2021 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.dmaapadapter.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.dmaapadapter.configuration.WebClientConfig.HttpProxyConfig;
  32 import org.slf4j.Logger;
  33 import org.slf4j.LoggerFactory;
  34 import org.springframework.http.MediaType;
  35 import org.springframework.http.ResponseEntity;
  36 import org.springframework.http.client.reactive.ReactorClientHttpConnector;
  37 import org.springframework.lang.Nullable;
  38 import org.springframework.web.reactive.function.client.ExchangeStrategies;
  39 import org.springframework.web.reactive.function.client.WebClient;
  40 import org.springframework.web.reactive.function.client.WebClient.RequestHeadersSpec;
  41 import org.springframework.web.reactive.function.client.WebClientResponseException;
  42
  43 import reactor.core.publisher.Mono;
  44 import reactor.netty.http.client.HttpClient;
  45 import reactor.netty.transport.ProxyProvider;
  46
  47 /**
  48  * Generic reactive REST client.
  49  */
  50 public class AsyncRestClient {
  51
  52     private static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
  53     private WebClient webClient = null;
  54     private final String baseUrl;
  55     private static final AtomicInteger sequenceNumber = new AtomicInteger();
  56     private final SslContext sslContext;
  57     private final HttpProxyConfig httpProxyConfig;
  58
  59     public AsyncRestClient(String baseUrl, @Nullable SslContext sslContext, @Nullable HttpProxyConfig httpProxyConfig) {
  60         this.baseUrl = baseUrl;
  61         this.sslContext = sslContext;
  62         this.httpProxyConfig = httpProxyConfig;
  63     }
  64
  65     public Mono<ResponseEntity<String>> postForEntity(String uri, @Nullable String body) {
  66         Object traceTag = createTraceTag();
  67         logger.debug("{} POST uri = '{}{}''", traceTag, baseUrl, uri);
  68         logger.trace("{} POST body: {}", traceTag, body);
  69         Mono<String> bodyProducer = body != null ? Mono.just(body) : Mono.empty();
  70         return getWebClient() //
  71                 .flatMap(client -> {
  72                     RequestHeadersSpec<?> request = client.post() //
  73                             .uri(uri) //
  74                             .contentType(MediaType.APPLICATION_JSON) //
  75                             .body(bodyProducer, String.class);
  76                     return retrieve(traceTag, request);
  77                 });
  78     }
  79
  80     public Mono<String> post(String uri, @Nullable String body) {
  81         return postForEntity(uri, body) //
  82                 .flatMap(this::toBody);
  83     }
  84
  85     public Mono<String> postWithAuthHeader(String uri, String body, String username, String password) {
  86         Object traceTag = createTraceTag();
  87         logger.debug("{} POST (auth) uri = '{}{}''", traceTag, baseUrl, uri);
  88         logger.trace("{} POST body: {}", traceTag, body);
  89         return getWebClient() //
  90                 .flatMap(client -> {
  91                     RequestHeadersSpec<?> request = client.post() //
  92                             .uri(uri) //
  93                             .headers(headers -> headers.setBasicAuth(username, password)) //
  94                             .contentType(MediaType.APPLICATION_JSON) //
  95                             .bodyValue(body);
  96                     return retrieve(traceTag, request) //
  97                             .flatMap(this::toBody);
  98                 });
  99     }
 100
 101     public Mono<ResponseEntity<String>> putForEntity(String uri, String body) {
 102         Object traceTag = createTraceTag();
 103         logger.debug("{} PUT uri = '{}{}''", traceTag, baseUrl, uri);
 104         logger.trace("{} PUT body: {}", traceTag, body);
 105         return getWebClient() //
 106                 .flatMap(client -> {
 107                     RequestHeadersSpec<?> request = client.put() //
 108                             .uri(uri) //
 109                             .contentType(MediaType.APPLICATION_JSON) //
 110                             .bodyValue(body);
 111                     return retrieve(traceTag, request);
 112                 });
 113     }
 114
 115     public Mono<ResponseEntity<String>> putForEntity(String uri) {
 116         Object traceTag = createTraceTag();
 117         logger.debug("{} PUT uri = '{}{}''", traceTag, baseUrl, uri);
 118         logger.trace("{} PUT body: <empty>", traceTag);
 119         return getWebClient() //
 120                 .flatMap(client -> {
 121                     RequestHeadersSpec<?> request = client.put() //
 122                             .uri(uri);
 123                     return retrieve(traceTag, request);
 124                 });
 125     }
 126
 127     public Mono<String> put(String uri, String body) {
 128         return putForEntity(uri, body) //
 129                 .flatMap(this::toBody);
 130     }
 131
 132     public Mono<ResponseEntity<String>> getForEntity(String uri) {
 133         Object traceTag = createTraceTag();
 134         logger.debug("{} GET uri = '{}{}''", traceTag, baseUrl, uri);
 135         return getWebClient() //
 136                 .flatMap(client -> {
 137                     RequestHeadersSpec<?> request = client.get().uri(uri);
 138                     return retrieve(traceTag, request);
 139                 });
 140     }
 141
 142     public Mono<String> get(String uri) {
 143         return getForEntity(uri) //
 144                 .flatMap(this::toBody);
 145     }
 146
 147     public Mono<ResponseEntity<String>> deleteForEntity(String uri) {
 148         Object traceTag = createTraceTag();
 149         logger.debug("{} DELETE uri = '{}{}''", traceTag, baseUrl, uri);
 150         return getWebClient() //
 151                 .flatMap(client -> {
 152                     RequestHeadersSpec<?> request = client.delete().uri(uri);
 153                     return retrieve(traceTag, request);
 154                 });
 155     }
 156
 157     public Mono<String> delete(String uri) {
 158         return deleteForEntity(uri) //
 159                 .flatMap(this::toBody);
 160     }
 161
 162     private Mono<ResponseEntity<String>> retrieve(Object traceTag, RequestHeadersSpec<?> request) {
 163         final Class<String> clazz = String.class;
 164         return request.retrieve() //
 165                 .toEntity(clazz) //
 166                 .doOnNext(entity -> logReceivedData(traceTag, entity)) //
 167                 .doOnError(throwable -> onHttpError(traceTag, throwable));
 168     }
 169
 170     private void logReceivedData(Object traceTag, ResponseEntity<String> entity) {
 171         logger.trace("{} Received: {} {}", traceTag, entity.getBody(), entity.getHeaders().getContentType());
 172     }
 173
 174     private static Object createTraceTag() {
 175         return sequenceNumber.incrementAndGet();
 176     }
 177
 178     private void onHttpError(Object traceTag, Throwable t) {
 179         if (t instanceof WebClientResponseException) {
 180             WebClientResponseException exception = (WebClientResponseException) t;
 181             logger.debug("{} HTTP error status = '{}', body '{}'", traceTag, exception.getStatusCode(),
 182                     exception.getResponseBodyAsString());
 183         } else {
 184             logger.debug("{} HTTP error {}", traceTag, t.getMessage());
 185         }
 186     }
 187
 188     private Mono<String> toBody(ResponseEntity<String> entity) {
 189         if (entity.getBody() == null) {
 190             return Mono.just("");
 191         } else {
 192             return Mono.just(entity.getBody());
 193         }
 194     }
 195
 196     private boolean isHttpProxyConfigured() {
 197         return httpProxyConfig != null && httpProxyConfig.httpProxyPort() > 0
 198                 && !httpProxyConfig.httpProxyHost().isEmpty();
 199     }
 200
 201     private HttpClient buildHttpClient() {
 202         HttpClient httpClient = HttpClient.create() //
 203                 .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 10_000) //
 204                 .doOnConnected(connection -> {
 205                     connection.addHandlerLast(new ReadTimeoutHandler(30));
 206                     connection.addHandlerLast(new WriteTimeoutHandler(30));
 207                 });
 208
 209         if (this.sslContext != null) {
 210             httpClient = httpClient.secure(ssl -> ssl.sslContext(sslContext));
 211         }
 212
 213         if (isHttpProxyConfigured()) {
 214             httpClient = httpClient.proxy(proxy -> proxy.type(ProxyProvider.Proxy.HTTP)
 215                     .host(httpProxyConfig.httpProxyHost()).port(httpProxyConfig.httpProxyPort()));
 216         }
 217         return httpClient;
 218     }
 219
 220     private WebClient buildWebClient(String baseUrl) {
 221         final HttpClient httpClient = buildHttpClient();
 222         ExchangeStrategies exchangeStrategies = ExchangeStrategies.builder() //
 223                 .codecs(configurer -> configurer.defaultCodecs().maxInMemorySize(-1)) //
 224                 .build();
 225         return WebClient.builder() //
 226                 .clientConnector(new ReactorClientHttpConnector(httpClient)) //
 227                 .baseUrl(baseUrl) //
 228                 .exchangeStrategies(exchangeStrategies) //
 229                 .build();
 230     }
 231
 232     private Mono<WebClient> getWebClient() {
 233         if (this.webClient == null) {
 234             this.webClient = buildWebClient(baseUrl);
 235         }
 236         return Mono.just(buildWebClient(baseUrl));
 237     }
 238
 239 }