policy-agent/src/main/java/org/oransc/policyagent/clients/AsyncRestClient.java

   1 /*-
   2  * ========================LICENSE_START=================================
   3  * O-RAN-SC
   4  * %%
   5  * Copyright (C) 2019 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.oransc.policyagent.clients;
  22
  23 import io.netty.channel.ChannelOption;
  24 import io.netty.handler.ssl.SslContext;
  25 import io.netty.handler.ssl.SslContextBuilder;
  26 import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
  27 import io.netty.handler.timeout.ReadTimeoutHandler;
  28 import io.netty.handler.timeout.WriteTimeoutHandler;
  29
  30 import java.io.FileInputStream;
  31 import java.io.IOException;
  32 import java.io.InputStream;
  33 import java.lang.invoke.MethodHandles;
  34 import java.security.KeyStore;
  35 import java.security.KeyStoreException;
  36 import java.security.NoSuchAlgorithmException;
  37 import java.security.cert.Certificate;
  38 import java.security.cert.CertificateException;
  39 import java.security.cert.X509Certificate;
  40 import java.util.Collections;
  41 import java.util.List;
  42 import java.util.concurrent.atomic.AtomicInteger;
  43 import java.util.stream.Collectors;
  44
  45 import javax.net.ssl.KeyManagerFactory;
  46
  47 import org.oransc.policyagent.configuration.WebClientConfig;
  48 import org.slf4j.Logger;
  49 import org.slf4j.LoggerFactory;
  50 import org.springframework.http.MediaType;
  51 import org.springframework.http.ResponseEntity;
  52 import org.springframework.http.client.reactive.ReactorClientHttpConnector;
  53 import org.springframework.lang.Nullable;
  54 import org.springframework.util.ResourceUtils;
  55 import org.springframework.web.reactive.function.client.ExchangeStrategies;
  56 import org.springframework.web.reactive.function.client.WebClient;
  57 import org.springframework.web.reactive.function.client.WebClient.RequestHeadersSpec;
  58 import org.springframework.web.reactive.function.client.WebClientResponseException;
  59
  60 import reactor.core.publisher.Mono;
  61 import reactor.netty.http.client.HttpClient;
  62 import reactor.netty.resources.ConnectionProvider;
  63 import reactor.netty.tcp.TcpClient;
  64
  65 /**
  66  * Generic reactive REST client.
  67  */
  68 public class AsyncRestClient {
  69     private static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
  70     private WebClient webClient = null;
  71     private final String baseUrl;
  72     private static final AtomicInteger sequenceNumber = new AtomicInteger();
  73     private final WebClientConfig clientConfig;
  74     static KeyStore clientTrustStore = null;
  75     private boolean sslEnabled = true;
  76
  77     public AsyncRestClient(String baseUrl) {
  78         this(baseUrl, null);
  79         this.sslEnabled = false;
  80     }
  81
  82     public AsyncRestClient(String baseUrl, WebClientConfig config) {
  83         this.baseUrl = baseUrl;
  84         this.clientConfig = config;
  85     }
  86
  87     public Mono<ResponseEntity<String>> postForEntity(String uri, @Nullable String body) {
  88         Object traceTag = createTraceTag();
  89         logger.debug("{} POST uri = '{}{}''", traceTag, baseUrl, uri);
  90         logger.trace("{} POST body: {}", traceTag, body);
  91         Mono<String> bodyProducer = body != null ? Mono.just(body) : Mono.empty();
  92         return getWebClient() //
  93             .flatMap(client -> {
  94                 RequestHeadersSpec<?> request = client.post() //
  95                     .uri(uri) //
  96                     .contentType(MediaType.APPLICATION_JSON) //
  97                     .body(bodyProducer, String.class);
  98                 return retrieve(traceTag, request);
  99             });
 100     }
 101
 102     public Mono<String> post(String uri, @Nullable String body) {
 103         return postForEntity(uri, body) //
 104             .flatMap(this::toBody);
 105     }
 106
 107     public Mono<String> postWithAuthHeader(String uri, String body, String username, String password) {
 108         Object traceTag = createTraceTag();
 109         logger.debug("{} POST (auth) uri = '{}{}''", traceTag, baseUrl, uri);
 110         logger.trace("{} POST body: {}", traceTag, body);
 111         return getWebClient() //
 112             .flatMap(client -> {
 113                 RequestHeadersSpec<?> request = client.post() //
 114                     .uri(uri) //
 115                     .headers(headers -> headers.setBasicAuth(username, password)) //
 116                     .contentType(MediaType.APPLICATION_JSON) //
 117                     .bodyValue(body);
 118                 return retrieve(traceTag, request) //
 119                     .flatMap(this::toBody);
 120             });
 121     }
 122
 123     public Mono<ResponseEntity<String>> putForEntity(String uri, String body) {
 124         Object traceTag = createTraceTag();
 125         logger.debug("{} PUT uri = '{}{}''", traceTag, baseUrl, uri);
 126         logger.trace("{} PUT body: {}", traceTag, body);
 127         return getWebClient() //
 128             .flatMap(client -> {
 129                 RequestHeadersSpec<?> request = client.put() //
 130                     .uri(uri) //
 131                     .contentType(MediaType.APPLICATION_JSON) //
 132                     .bodyValue(body);
 133                 return retrieve(traceTag, request);
 134             });
 135     }
 136
 137     public Mono<ResponseEntity<String>> putForEntity(String uri) {
 138         Object traceTag = createTraceTag();
 139         logger.debug("{} PUT uri = '{}{}''", traceTag, baseUrl, uri);
 140         logger.trace("{} PUT body: <empty>", traceTag);
 141         return getWebClient() //
 142             .flatMap(client -> {
 143                 RequestHeadersSpec<?> request = client.put() //
 144                     .uri(uri);
 145                 return retrieve(traceTag, request);
 146             });
 147     }
 148
 149     public Mono<String> put(String uri, String body) {
 150         return putForEntity(uri, body) //
 151             .flatMap(this::toBody);
 152     }
 153
 154     public Mono<ResponseEntity<String>> getForEntity(String uri) {
 155         Object traceTag = createTraceTag();
 156         logger.debug("{} GET uri = '{}{}''", traceTag, baseUrl, uri);
 157         return getWebClient() //
 158             .flatMap(client -> {
 159                 RequestHeadersSpec<?> request = client.get().uri(uri);
 160                 return retrieve(traceTag, request);
 161             });
 162     }
 163
 164     public Mono<String> get(String uri) {
 165         return getForEntity(uri) //
 166             .flatMap(this::toBody);
 167     }
 168
 169     public Mono<ResponseEntity<String>> deleteForEntity(String uri) {
 170         Object traceTag = createTraceTag();
 171         logger.debug("{} DELETE uri = '{}{}''", traceTag, baseUrl, uri);
 172         return getWebClient() //
 173             .flatMap(client -> {
 174                 RequestHeadersSpec<?> request = client.delete().uri(uri);
 175                 return retrieve(traceTag, request);
 176             });
 177     }
 178
 179     public Mono<String> delete(String uri) {
 180         return deleteForEntity(uri) //
 181             .flatMap(this::toBody);
 182     }
 183
 184     private Mono<ResponseEntity<String>> retrieve(Object traceTag, RequestHeadersSpec<?> request) {
 185         final Class<String> clazz = String.class;
 186         return request.retrieve() //
 187             .toEntity(clazz) //
 188             .doOnNext(entity -> logger.trace("{} Received: {}", traceTag, entity.getBody())) //
 189             .doOnError(throwable -> onHttpError(traceTag, throwable));
 190     }
 191
 192     private static Object createTraceTag() {
 193         return sequenceNumber.incrementAndGet();
 194     }
 195
 196     private void onHttpError(Object traceTag, Throwable t) {
 197         if (t instanceof WebClientResponseException) {
 198             WebClientResponseException exception = (WebClientResponseException) t;
 199             logger.debug("{} HTTP error status = '{}', body '{}'", traceTag, exception.getStatusCode(),
 200                 exception.getResponseBodyAsString());
 201         } else {
 202             logger.debug("{} HTTP error", traceTag, t);
 203         }
 204     }
 205
 206     private Mono<String> toBody(ResponseEntity<String> entity) {
 207         if (entity.getBody() == null) {
 208             return Mono.just("");
 209         } else {
 210             return Mono.just(entity.getBody());
 211         }
 212     }
 213
 214     private boolean isCertificateEntry(KeyStore trustStore, String alias) {
 215         try {
 216             return trustStore.isCertificateEntry(alias);
 217         } catch (KeyStoreException e) {
 218             logger.error("Error reading truststore {}", e.getMessage());
 219             return false;
 220         }
 221     }
 222
 223     private Certificate getCertificate(KeyStore trustStore, String alias) {
 224         try {
 225             return trustStore.getCertificate(alias);
 226         } catch (KeyStoreException e) {
 227             logger.error("Error reading truststore {}", e.getMessage());
 228             return null;
 229         }
 230     }
 231
 232     private static synchronized KeyStore getTrustStore(String trustStorePath, String trustStorePass)
 233         throws NoSuchAlgorithmException, CertificateException, IOException, KeyStoreException {
 234         if (clientTrustStore == null) {
 235             KeyStore store = KeyStore.getInstance(KeyStore.getDefaultType());
 236             store.load(new FileInputStream(ResourceUtils.getFile(trustStorePath)), trustStorePass.toCharArray());
 237             clientTrustStore = store;
 238         }
 239         return clientTrustStore;
 240     }
 241
 242     private SslContext createSslContextRejectingUntrustedPeers(String trustStorePath, String trustStorePass,
 243         KeyManagerFactory keyManager)
 244         throws NoSuchAlgorithmException, CertificateException, IOException, KeyStoreException {
 245
 246         final KeyStore trustStore = getTrustStore(trustStorePath, trustStorePass);
 247         List<Certificate> certificateList = Collections.list(trustStore.aliases()).stream() //
 248             .filter(alias -> isCertificateEntry(trustStore, alias)) //
 249             .map(alias -> getCertificate(trustStore, alias)) //
 250             .collect(Collectors.toList());
 251         final X509Certificate[] certificates = certificateList.toArray(new X509Certificate[certificateList.size()]);
 252
 253         return SslContextBuilder.forClient() //
 254             .keyManager(keyManager) //
 255             .trustManager(certificates) //
 256             .build();
 257     }
 258
 259     private SslContext createSslContext(KeyManagerFactory keyManager)
 260         throws NoSuchAlgorithmException, CertificateException, KeyStoreException, IOException {
 261         if (this.clientConfig.isTrustStoreUsed()) {
 262             return createSslContextRejectingUntrustedPeers(this.clientConfig.trustStore(),
 263                 this.clientConfig.trustStorePassword(), keyManager);
 264         } else {
 265             // Trust anyone
 266             return SslContextBuilder.forClient() //
 267                 .keyManager(keyManager) //
 268                 .trustManager(InsecureTrustManagerFactory.INSTANCE) //
 269                 .build();
 270         }
 271     }
 272
 273     private TcpClient createTcpClientSecure(SslContext sslContext) {
 274         return TcpClient.create(ConnectionProvider.newConnection()) //
 275             .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 10_000) //
 276             .secure(c -> c.sslContext(sslContext)) //
 277             .doOnConnected(connection -> {
 278                 connection.addHandlerLast(new ReadTimeoutHandler(30));
 279                 connection.addHandlerLast(new WriteTimeoutHandler(30));
 280             });
 281     }
 282
 283     private TcpClient createTcpClientInsecure() {
 284         return TcpClient.create(ConnectionProvider.newConnection()) //
 285             .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 10_000) //
 286             .doOnConnected(connection -> {
 287                 connection.addHandlerLast(new ReadTimeoutHandler(30));
 288                 connection.addHandlerLast(new WriteTimeoutHandler(30));
 289             });
 290     }
 291
 292     private WebClient createWebClient(String baseUrl, TcpClient tcpClient) {
 293         HttpClient httpClient = HttpClient.from(tcpClient);
 294         ReactorClientHttpConnector connector = new ReactorClientHttpConnector(httpClient);
 295         ExchangeStrategies exchangeStrategies = ExchangeStrategies.builder() //
 296             .codecs(configurer -> configurer.defaultCodecs().maxInMemorySize(-1)) //
 297             .build();
 298         return WebClient.builder() //
 299             .clientConnector(connector) //
 300             .baseUrl(baseUrl) //
 301             .exchangeStrategies(exchangeStrategies) //
 302             .build();
 303     }
 304
 305     private Mono<WebClient> getWebClient() {
 306         if (this.webClient == null) {
 307             try {
 308                 if (this.sslEnabled) {
 309                     final KeyManagerFactory keyManager =
 310                         KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
 311                     final KeyStore keyStore = KeyStore.getInstance(this.clientConfig.keyStoreType());
 312                     final String keyStoreFile = this.clientConfig.keyStore();
 313                     final String keyStorePassword = this.clientConfig.keyStorePassword();
 314                     final String keyPassword = this.clientConfig.keyPassword();
 315                     try (final InputStream inputStream = new FileInputStream(keyStoreFile)) {
 316                         keyStore.load(inputStream, keyStorePassword.toCharArray());
 317                     }
 318                     keyManager.init(keyStore, keyPassword.toCharArray());
 319                     SslContext sslContext = createSslContext(keyManager);
 320                     TcpClient tcpClient = createTcpClientSecure(sslContext);
 321                     this.webClient = createWebClient(this.baseUrl, tcpClient);
 322                 } else {
 323                     TcpClient tcpClient = createTcpClientInsecure();
 324                     this.webClient = createWebClient(this.baseUrl, tcpClient);
 325                 }
 326             } catch (Exception e) {
 327                 logger.error("Could not create WebClient {}", e.getMessage());
 328                 return Mono.error(e);
 329             }
 330         }
 331         return Mono.just(this.webClient);
 332     }
 333
 334 }