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

   1 /*-
   2  * ========================LICENSE_START=================================
   3  * O-RAN-SC
   4  * %%
   5  * Copyright (C) 2022 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.pmlog.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.pmlog.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.ExchangeFilterFunction;
  39 import org.springframework.web.reactive.function.client.ExchangeStrategies;
  40 import org.springframework.web.reactive.function.client.WebClient;
  41 import org.springframework.web.reactive.function.client.WebClient.RequestHeadersSpec;
  42 import org.springframework.web.reactive.function.client.WebClientResponseException;
  43
  44 import reactor.core.publisher.Mono;
  45 import reactor.netty.http.client.HttpClient;
  46 import reactor.netty.transport.ProxyProvider;
  47
  48 /**
  49  * Generic reactive REST client.
  50  */
  51 public class AsyncRestClient {
  52
  53     private static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
  54     private WebClient webClient = null;
  55     private final String baseUrl;
  56     private static final AtomicInteger sequenceNumber = new AtomicInteger();
  57     private final SslContext sslContext;
  58     private final HttpProxyConfig httpProxyConfig;
  59     private final SecurityContext securityContext;
  60
  61     public AsyncRestClient(String baseUrl, @Nullable SslContext sslContext, @Nullable HttpProxyConfig httpProxyConfig,
  62             SecurityContext securityContext) {
  63         this.baseUrl = baseUrl;
  64         this.sslContext = sslContext;
  65         this.httpProxyConfig = httpProxyConfig;
  66         this.securityContext = securityContext;
  67     }
  68
  69     @SuppressWarnings("java:S4449") // contentType, is not @Nullable
  70     public Mono<ResponseEntity<String>> postForEntity(String uri, @Nullable String body,
  71             @Nullable MediaType mediaType) {
  72         Mono<String> bodyProducer = body != null ? Mono.just(body) : Mono.empty();
  73
  74         RequestHeadersSpec<?> request = getWebClient() //
  75                 .post() //
  76                 .uri(uri) //
  77                 .contentType(mediaType) //
  78                 .body(bodyProducer, String.class);
  79         return retrieve(request);
  80     }
  81
  82     public Mono<String> post(String uri, @Nullable String body, @Nullable MediaType mediaType) {
  83         return postForEntity(uri, body, mediaType) //
  84                 .map(this::toBody);
  85     }
  86
  87     public Mono<ResponseEntity<String>> putForEntity(String uri, String body) {
  88         RequestHeadersSpec<?> request = getWebClient() //
  89                 .put() //
  90                 .uri(uri) //
  91                 .contentType(MediaType.APPLICATION_JSON) //
  92                 .bodyValue(body);
  93         return retrieve(request);
  94     }
  95
  96     public Mono<String> put(String uri, String body) {
  97         return putForEntity(uri, body) //
  98                 .map(this::toBody);
  99     }
 100
 101     public Mono<ResponseEntity<String>> getForEntity(String uri) {
 102         RequestHeadersSpec<?> request = getWebClient().get().uri(uri);
 103         return retrieve(request);
 104     }
 105
 106     public Mono<String> get(String uri) {
 107         return getForEntity(uri) //
 108                 .map(this::toBody);
 109     }
 110
 111     public Mono<ResponseEntity<String>> deleteForEntity(String uri) {
 112         RequestHeadersSpec<?> request = getWebClient().delete().uri(uri);
 113         return retrieve(request);
 114     }
 115
 116     public Mono<String> delete(String uri) {
 117         return deleteForEntity(uri) //
 118                 .map(this::toBody);
 119     }
 120
 121     public Mono<ResponseEntity<String>> postForEntity(String uri, @Nullable String body) {
 122         Mono<String> bodyProducer = body != null ? Mono.just(body) : Mono.empty();
 123
 124         RequestHeadersSpec<?> request = getWebClient() //
 125                 .post() //
 126                 .uri(uri) //
 127                 .contentType(MediaType.APPLICATION_JSON) //
 128                 .body(bodyProducer, String.class);
 129         return retrieve(request);
 130     }
 131
 132     public Mono<String> post(String uri, @Nullable String body) {
 133         return postForEntity(uri, body) //
 134                 .map(this::toBody);
 135     }
 136
 137     private Mono<ResponseEntity<String>> retrieve(RequestHeadersSpec<?> request) {
 138         if (securityContext.isConfigured()) {
 139             request.headers(h -> h.setBearerAuth(securityContext.getBearerAuthToken()));
 140         }
 141         return request.retrieve() //
 142                 .toEntity(String.class) //
 143                 .doOnError(this::onError); //
 144     }
 145
 146     private void onError(Throwable t) {
 147         if (t instanceof WebClientResponseException) {
 148             WebClientResponseException e = (WebClientResponseException) t;
 149             logger.debug("Response error: {}", e.getResponseBodyAsString());
 150         }
 151     }
 152
 153     private static Object createTraceTag() {
 154         return sequenceNumber.incrementAndGet();
 155     }
 156
 157     private String toBody(ResponseEntity<String> entity) {
 158         if (entity.getBody() == null) {
 159             return "";
 160         } else {
 161             return entity.getBody();
 162         }
 163     }
 164
 165     private boolean isHttpProxyConfigured() {
 166         return httpProxyConfig != null && httpProxyConfig.getHttpProxyPort() > 0
 167                 && !httpProxyConfig.getHttpProxyHost().isEmpty();
 168     }
 169
 170     private HttpClient buildHttpClient() {
 171         HttpClient httpClient = HttpClient.create() //
 172                 .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 10_000) //
 173                 .doOnConnected(connection -> {
 174                     connection.addHandlerLast(new ReadTimeoutHandler(30));
 175                     connection.addHandlerLast(new WriteTimeoutHandler(30));
 176                 });
 177
 178         if (this.sslContext != null) {
 179             httpClient = httpClient.secure(ssl -> ssl.sslContext(sslContext));
 180         }
 181
 182         if (isHttpProxyConfigured()) {
 183             httpClient = httpClient.proxy(proxy -> proxy.type(ProxyProvider.Proxy.HTTP)
 184                     .host(httpProxyConfig.getHttpProxyHost()).port(httpProxyConfig.getHttpProxyPort()));
 185         }
 186         return httpClient;
 187     }
 188
 189     public WebClient buildWebClient(String baseUrl) {
 190         Object traceTag = createTraceTag();
 191
 192         final HttpClient httpClient = buildHttpClient();
 193         ExchangeStrategies exchangeStrategies = ExchangeStrategies.builder() //
 194                 .codecs(configurer -> configurer.defaultCodecs().maxInMemorySize(-1)) //
 195                 .build();
 196
 197         ExchangeFilterFunction reqLogger = ExchangeFilterFunction.ofRequestProcessor(req -> {
 198             logger.debug("{} {} uri = '{}''", traceTag, req.method(), req.url());
 199             return Mono.just(req);
 200         });
 201
 202         ExchangeFilterFunction respLogger = ExchangeFilterFunction.ofResponseProcessor(resp -> {
 203             logger.debug("{} resp: {}", traceTag, resp.statusCode());
 204             return Mono.just(resp);
 205         });
 206
 207         return WebClient.builder() //
 208                 .clientConnector(new ReactorClientHttpConnector(httpClient)) //
 209                 .baseUrl(baseUrl) //
 210                 .exchangeStrategies(exchangeStrategies) //
 211                 .filter(reqLogger) //
 212                 .filter(respLogger) //
 213                 .build();
 214     }
 215
 216     private WebClient getWebClient() {
 217         if (this.webClient == null) {
 218             this.webClient = buildWebClient(baseUrl);
 219         }
 220         return this.webClient;
 221     }
 222 }