Create an evolution of HTTP Client

* simplify the API
* use new http client in old one for compatibility
* deprecate old one

Issue-ID: DCAEGEN2-1010
Change-Id: Ief681ba536a37b29c10d133c61a1326a003ed308
Signed-off-by: Piotr Jaszczyk <piotr.jaszczyk@nokia.com>

9 files changed, 610 insertions, 104 deletions

diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/CloudHttpClient.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/CloudHttpClient.java
index ac790cb2..e83a069e 100644
--- a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/CloudHttpClient.java
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/CloudHttpClient.java
@@ -21,139 +21,102 @@
 package org.onap.dcaegen2.services.sdk.rest.services.adapters.http;
 
 import com.google.gson.Gson;
-import io.netty.handler.codec.http.HttpStatusClass;
 import io.netty.handler.ssl.SslContext;
-import io.vavr.collection.Stream;
-import java.io.IOException;
+import io.vavr.collection.HashMap;
 import java.util.Collections;
 import java.util.Map;
-import java.util.function.BiConsumer;
-import java.util.stream.Collectors;
 import org.onap.dcaegen2.services.sdk.rest.services.model.ClientModel;
 import org.onap.dcaegen2.services.sdk.rest.services.model.JsonBodyBuilder;
 import org.onap.dcaegen2.services.sdk.rest.services.model.logging.RequestDiagnosticContext;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import reactor.core.publisher.Mono;
-import reactor.netty.ByteBufFlux;
 import reactor.netty.http.client.HttpClient;
-import reactor.netty.http.client.HttpClientRequest;
 import reactor.netty.http.client.HttpClientResponse;
 
 
 /**
  * @author <a href="mailto:przemyslaw.wasala@nokia.com">Przemysław Wąsala</a> on 11/15/18
+ * @deprecated use {@link RxHttpClient} instead
  */
-
+@Deprecated
 public class CloudHttpClient {
 
-    private static final Logger LOGGER = LoggerFactory.getLogger(CloudHttpClient.class);
     private final Gson gson = new Gson();
-    private final HttpClient httpClient;
-
-    public CloudHttpClient() {
-        this(HttpClient.create());
-    }
+    private final RxHttpClient httpClient;
 
-    public CloudHttpClient(SslContext sslContext) {
-        this(HttpClient.create().secure(sslContextSpec -> sslContextSpec.sslContext(sslContext)));
-    }
-
-    CloudHttpClient(HttpClient httpClient) {
+    CloudHttpClient(RxHttpClient httpClient) {
         this.httpClient = httpClient;
-
     }
 
-
-
-    @Deprecated
-    public <T> Mono<T> get(String url, RequestDiagnosticContext context, Class<T> bodyClass) {
-        return get(url, context, Collections.EMPTY_MAP, bodyClass);
+    public CloudHttpClient() {
+        this(RxHttpClient.create());
     }
 
-    @Deprecated
-    public <T> Mono<T> get(String url, RequestDiagnosticContext context, Map<String, String> customHeaders,
-        Class<T> bodyClass) {
-        final HttpClient clientWithHeaders = getHttpClientWithHeaders(context, customHeaders);
-        return callHttpGet(clientWithHeaders, url, bodyClass);
+    public CloudHttpClient(SslContext sslContext) {
+        this(RxHttpClient.create(sslContext));
     }
 
     public <T> Mono<T> get(String url, Class<T> bodyClass) {
-        return callHttpGet(httpClient, url, bodyClass);
-    }
-
-    public Mono<HttpClientResponse> post(String url, RequestDiagnosticContext context, Map<String, String> customHeaders,
-        JsonBodyBuilder jsonBodyBuilder, ClientModel clientModel) {
-        final HttpClient clientWithHeaders = getHttpClientWithHeaders(context, customHeaders);
-        return callHttpPost(clientWithHeaders, url, jsonBodyBuilder, clientModel);
+        return get(url, RequestDiagnosticContext.create(), bodyClass);
     }
 
-    public Mono<HttpClientResponse> patch(String url, RequestDiagnosticContext context, Map<String, String> customHeaders,
-        JsonBodyBuilder jsonBodyBuilder, ClientModel clientModel) {
-        final HttpClient clientWithHeaders = getHttpClientWithHeaders(context, customHeaders);
-        return callHttpPatch(clientWithHeaders, url, jsonBodyBuilder, clientModel);
-    }
-
-    private HttpClient getHttpClientWithHeaders(RequestDiagnosticContext context, Map<String, String> customHeaders) {
-        final HttpClient clientWithHeaders = httpClient
-            .doOnRequest((req, conn) -> logRequest(context, req))
-            .doOnResponse((rsp, conn) -> logResponse(context, rsp))
-            .headers(hdrs -> context.remoteCallHttpHeaders().forEach((BiConsumer<String, String>) hdrs::set))
-            .headers(hdrs -> customHeaders.forEach(hdrs::set));
-        return clientWithHeaders;
-    }
-
-    private <T> Mono<T> callHttpGet(HttpClient client, String url, Class<T> bodyClass) {
-        return client.get()
-            .uri(url)
-            .responseSingle((resp, content) -> HttpStatusClass.SUCCESS.contains(resp.status().code())
-                ? content.asString()
-                : Mono.error(createException(url, resp)))
-            .map(body -> parseJson(body, bodyClass));
-    }
-
-    private <T extends ClientModel> Mono<HttpClientResponse> callHttpPost(HttpClient client, String url,
-        JsonBodyBuilder<T> jsonBodyBuilder, T clientModel) {
-        return client.baseUrl(url).post()
-            .send(ByteBufFlux.fromString(Mono.just(jsonBodyBuilder.createJsonBody(clientModel))))
-            .responseSingle((httpClientResponse, byteBufMono) -> Mono.just(httpClientResponse));
-    }
-
-    private <T extends ClientModel> Mono<HttpClientResponse> callHttpPatch(HttpClient client, String url,
-        JsonBodyBuilder<T> jsonBodyBuilder, T clientModel) {
-        String jsonBodyRequest = jsonBodyBuilder.createJsonBody(clientModel);
-        LOGGER.debug( String.format("Json body request: %s ",jsonBodyRequest));
-        return client.baseUrl(url).patch()
-            .send(ByteBufFlux.fromString(Mono.just(jsonBodyRequest)))
-            .responseSingle((httpClientResponse, byteBufMono) -> Mono.just(httpClientResponse));
-    }
-
-    private Exception createException(String url, HttpClientResponse response) {
-        return new IOException(String.format("Request failed for URL '%s'. Response code: %s",
-            url,
-            response.status()));
-    }
-
-    private <T> T parseJson(String body, Class<T> bodyClass) {
-        return gson.fromJson(body, bodyClass);
-    }
-
-    private void logRequest(RequestDiagnosticContext context, HttpClientRequest httpClientRequest) {
-        context.withSlf4jMdc(LOGGER.isDebugEnabled(), () -> {
-            LOGGER.debug("Request: {} {} {}", httpClientRequest.method(), httpClientRequest.uri(), httpClientRequest.requestHeaders());
-            if (LOGGER.isTraceEnabled()) {
-                final String headers = Stream.ofAll(httpClientRequest.requestHeaders())
-                    .map(entry -> entry.getKey() + "=" + entry.getValue())
-                    .collect(Collectors.joining("\n"));
-                LOGGER.trace(headers);
-            }
-        });
+    public <T> Mono<T> get(String url, RequestDiagnosticContext context, Class<T> bodyClass) {
+        return get(url, context, Collections.emptyMap(), bodyClass);
+    }
+
+    public <T> Mono<T> get(
+            String url,
+            RequestDiagnosticContext context,
+            Map<String, String> customHeaders,
+            Class<T> bodyClass) {
+        return httpClient.call(
+                ImmutableHttpRequest.builder()
+                        .method(HttpMethod.GET)
+                        .url(url)
+                        .customHeaders(HashMap.ofAll(customHeaders))
+                        .diagnosticContext(context)
+                        .build())
+                .doOnNext(HttpResponse::throwIfUnsuccessful)
+                .map(HttpResponse::bodyAsString)
+                .map(body -> gson.fromJson(body, bodyClass));
+    }
+
+
+    public Mono<HttpClientResponse> post(
+            String url,
+            RequestDiagnosticContext context,
+            Map<String, String> customHeaders,
+            JsonBodyBuilder jsonBodyBuilder,
+            ClientModel clientModel) {
+        return callForRawResponse(url, context, customHeaders, jsonBodyBuilder, clientModel, HttpMethod.POST);
+    }
+
+    public Mono<HttpClientResponse> patch(
+            String url,
+            RequestDiagnosticContext context,
+            Map<String, String> customHeaders,
+            JsonBodyBuilder jsonBodyBuilder,
+            ClientModel clientModel) {
+        return callForRawResponse(url, context, customHeaders, jsonBodyBuilder, clientModel, HttpMethod.PATCH);
+    }
+
+
+    private Mono<HttpClientResponse> callForRawResponse(
+            String url,
+            RequestDiagnosticContext context,
+            Map<String, String> customHeaders,
+            JsonBodyBuilder jsonBodyBuilder,
+            ClientModel clientModel,
+            HttpMethod method) {
+        return httpClient.prepareRequest(
+                ImmutableHttpRequest.builder()
+                        .url(url)
+                        .customHeaders(HashMap.ofAll(customHeaders))
+                        .diagnosticContext(context)
+                        .body(RequestBody.fromString(jsonBodyBuilder.createJsonBody(clientModel)))
+                        .method(method)
+                        .build())
+                .responseSingle((httpClientResponse, byteBufMono) -> Mono.just(httpClientResponse));
     }
 
-    private void logResponse(RequestDiagnosticContext context, HttpClientResponse httpClientResponse) {
-        context.withSlf4jMdc(LOGGER.isDebugEnabled(), () -> {
-            LOGGER.debug("Response status: {}", httpClientResponse.status());
-        });
-    }
 }
 
diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpMethod.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpMethod.java
new file mode 100644
index 00000000..78e6789e
--- /dev/null
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpMethod.java
@@ -0,0 +1,48 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.rest.services.adapters.http;
+
+/**
+ * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
+ * @since March 2019
+ */
+public enum HttpMethod {
+
+    CONNECT(io.netty.handler.codec.http.HttpMethod.CONNECT),
+    DELETE(io.netty.handler.codec.http.HttpMethod.DELETE),
+    GET(io.netty.handler.codec.http.HttpMethod.GET),
+    HEAD(io.netty.handler.codec.http.HttpMethod.HEAD),
+    OPTIONS(io.netty.handler.codec.http.HttpMethod.OPTIONS),
+    POST(io.netty.handler.codec.http.HttpMethod.POST),
+    PATCH(io.netty.handler.codec.http.HttpMethod.PATCH),
+    PUT(io.netty.handler.codec.http.HttpMethod.PUT),
+    TRACE(io.netty.handler.codec.http.HttpMethod.TRACE);
+
+    private final io.netty.handler.codec.http.HttpMethod nettyMethod;
+
+    HttpMethod(io.netty.handler.codec.http.HttpMethod nettyMethod) {
+        this.nettyMethod = nettyMethod;
+    }
+
+    io.netty.handler.codec.http.HttpMethod asNetty() {
+        return nettyMethod;
+    }
+}
diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpRequest.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpRequest.java
new file mode 100644
index 00000000..78660833
--- /dev/null
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpRequest.java
@@ -0,0 +1,68 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.rest.services.adapters.http;
+
+import io.netty.buffer.ByteBuf;
+import io.vavr.collection.HashMap;
+import io.vavr.collection.Map;
+import java.util.function.BiFunction;
+import org.immutables.value.Value;
+import org.jetbrains.annotations.Nullable;
+import org.onap.dcaegen2.services.sdk.rest.services.model.logging.RequestDiagnosticContext;
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Mono;
+import reactor.netty.NettyOutbound;
+import reactor.netty.http.client.HttpClientRequest;
+
+/**
+ * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
+ * @since March 2019
+ */
+@Value.Immutable
+public interface HttpRequest {
+
+    String url();
+
+    HttpMethod method();
+
+    @Value.Default
+    default RequestDiagnosticContext diagnosticContext() {
+        return RequestDiagnosticContext.create();
+    }
+
+    @Value.Default
+    default Map<String, String> customHeaders() {
+        return HashMap.empty();
+    }
+
+    @Value.Default
+    default Publisher<ByteBuf> body() {
+        return Mono.empty();
+    }
+
+    @Value.Derived
+    default Map<String, String> headers() {
+        final RequestDiagnosticContext ctx = diagnosticContext();
+        return ctx == null
+                ? customHeaders()
+                : customHeaders().merge(ctx.remoteCallHttpHeaders());
+    }
+}
diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpResponse.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpResponse.java
new file mode 100644
index 00000000..ce100478
--- /dev/null
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpResponse.java
@@ -0,0 +1,77 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.rest.services.adapters.http;
+
+import com.google.gson.Gson;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import org.immutables.value.Value;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.exceptions.HttpException;
+
+/**
+ * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
+ * @since March 2019
+ */
+@Value.Immutable
+public interface HttpResponse {
+
+    String url();
+
+    int statusCode();
+
+    byte[] rawBody();
+
+    @Value.Default
+    default String statusReason() {
+        return "";
+    }
+
+    @Value.Derived
+    default boolean successful() {
+        return statusCode() >= 200 && statusCode() < 300;
+    }
+
+    @Value.Derived
+    default String bodyAsString() {
+        return bodyAsString(StandardCharsets.UTF_8);
+    }
+
+    @Value.Derived
+    default String bodyAsString(Charset charset) {
+        return new String(rawBody(), charset);
+    }
+
+    @Value.Derived
+    default <T> T bodyAsJson(Class<T> clazz) {
+        return bodyAsJson(StandardCharsets.UTF_8, new Gson(), clazz);
+    }
+
+    @Value.Derived
+    default <T> T bodyAsJson(Charset charset, Gson gson, Class<T> clazz) {
+        return gson.fromJson(bodyAsString(charset), clazz);
+    }
+
+    default void throwIfUnsuccessful() {
+        if (!successful()) {
+            throw new HttpException(url(), statusCode(), statusReason());
+        }
+    }
+}
diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/NettyHttpResponse.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/NettyHttpResponse.java
new file mode 100644
index 00000000..3dcd7098
--- /dev/null
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/NettyHttpResponse.java
@@ -0,0 +1,73 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.rest.services.adapters.http;
+
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.netty.handler.codec.http.HttpStatusClass;
+import java.nio.charset.Charset;
+
+/**
+ * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
+ * @since March 2019
+ */
+class NettyHttpResponse implements HttpResponse {
+
+    private final String url;
+    private final HttpResponseStatus status;
+    private final byte[] body;
+
+    NettyHttpResponse(String url, HttpResponseStatus status, byte[] body) {
+        this.url = url;
+        this.status = status;
+        this.body = body;
+    }
+
+    @Override
+    public String url() {
+        return url;
+    }
+
+    @Override
+    public boolean successful() {
+        return status.codeClass() == HttpStatusClass.SUCCESS;
+    }
+
+    @Override
+    public int statusCode() {
+        return status.code();
+    }
+
+    @Override
+    public String statusReason() {
+        return status.reasonPhrase();
+    }
+
+    @Override
+    public byte[] rawBody() {
+        return new byte[0];
+    }
+
+    @Override
+    public String bodyAsString(Charset charset) {
+        return new String(body, charset);
+    }
+
+}
diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RequestBody.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RequestBody.java
new file mode 100644
index 00000000..514ea0bf
--- /dev/null
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RequestBody.java
@@ -0,0 +1,53 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.rest.services.adapters.http;
+
+import com.google.gson.JsonElement;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufAllocator;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Mono;
+import reactor.netty.ByteBufFlux;
+
+/**
+ * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
+ * @since March 2019
+ */
+public final class RequestBody {
+
+    private RequestBody() {
+    }
+
+    public static Publisher<ByteBuf> fromString(String contents) {
+        return fromString(contents, StandardCharsets.UTF_8);
+    }
+
+    public static Publisher<ByteBuf> fromString(String contents, Charset charset) {
+        return ByteBufFlux.fromString(Mono.just(contents), charset, ByteBufAllocator.DEFAULT);
+    }
+
+    public static Publisher<ByteBuf> fromJson(JsonElement contents) {
+        return fromString(contents.toString());
+    }
+
+}
diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RxHttpClient.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RxHttpClient.java
new file mode 100644
index 00000000..f384c1c1
--- /dev/null
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RxHttpClient.java
@@ -0,0 +1,91 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=====================================
+ */
+package org.onap.dcaegen2.services.sdk.rest.services.adapters.http;
+
+import io.netty.handler.ssl.SslContext;
+import io.vavr.collection.Stream;
+import java.util.stream.Collectors;
+import org.onap.dcaegen2.services.sdk.rest.services.model.logging.RequestDiagnosticContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import reactor.core.publisher.Mono;
+import reactor.netty.http.client.HttpClient;
+import reactor.netty.http.client.HttpClient.ResponseReceiver;
+import reactor.netty.http.client.HttpClientRequest;
+import reactor.netty.http.client.HttpClientResponse;
+
+/**
+ * @since 1.1.4
+ */
+public class RxHttpClient {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(RxHttpClient.class);
+    private final HttpClient httpClient;
+
+    public static RxHttpClient create() {
+        return new RxHttpClient(HttpClient.create());
+    }
+
+    // TODO: hide netty from public api (io.netty.handler.ssl.SslContext)
+    public static RxHttpClient create(SslContext sslContext) {
+        return new RxHttpClient(HttpClient.create().secure(sslContextSpec -> sslContextSpec.sslContext(sslContext)));
+    }
+
+    RxHttpClient(HttpClient httpClient) {
+        this.httpClient = httpClient;
+    }
+
+    public Mono<HttpResponse> call(HttpRequest request) {
+        return prepareRequest(request)
+                .responseSingle((resp, content) ->
+                        content.asByteArray()
+                                .defaultIfEmpty(new byte[0])
+                                .map(bytes -> new NettyHttpResponse(request.url(), resp.status(), bytes)));
+    }
+
+    ResponseReceiver<?> prepareRequest(HttpRequest request) {
+        return httpClient
+                .doOnRequest((req, conn) -> logRequest(request.diagnosticContext(), req))
+                .doOnResponse((rsp, conn) -> logResponse(request.diagnosticContext(), rsp))
+                .headers(hdrs -> request.headers().forEach(hdr -> hdrs.set(hdr._1, hdr._2)))
+                .request(request.method().asNetty())
+                .send(request.body())
+                .uri(request.url());
+
+    }
+
+    private void logRequest(RequestDiagnosticContext context, HttpClientRequest httpClientRequest) {
+        context.withSlf4jMdc(LOGGER.isDebugEnabled(), () -> {
+            LOGGER.debug("Request: {} {} {}", httpClientRequest.method(), httpClientRequest.uri(),
+                    httpClientRequest.requestHeaders());
+            if (LOGGER.isTraceEnabled()) {
+                final String headers = Stream.ofAll(httpClientRequest.requestHeaders())
+                        .map(entry -> entry.getKey() + "=" + entry.getValue())
+                        .collect(Collectors.joining("\n"));
+                LOGGER.trace(headers);
+            }
+        });
+    }
+
+    private void logResponse(RequestDiagnosticContext context, HttpClientResponse httpClientResponse) {
+        context.withSlf4jMdc(LOGGER.isDebugEnabled(),
+                () -> LOGGER.debug("Response status: {}", httpClientResponse.status()));
+    }
+}
diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/exceptions/HttpException.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/exceptions/HttpException.java
new file mode 100644
index 00000000..9631f4c5
--- /dev/null
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/exceptions/HttpException.java
@@ -0,0 +1,45 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=====================================
+ */
+package org.onap.dcaegen2.services.sdk.rest.services.adapters.http.exceptions;
+
+/**
+ * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
+ * @since March 2019
+ */
+public class HttpException extends RuntimeException {
+
+    private final String url;
+    private final int responseCode;
+    private final String reason;
+
+    public HttpException(String url, int responseCode, String reason) {
+        this.url = url;
+        this.responseCode = responseCode;
+        this.reason = reason;
+    }
+
+    @Override
+    public String getMessage() {
+        return String.format("Request failed for URL '%s'. Response code: %d %s",
+                url,
+                responseCode,
+                reason);
+    }
+}
diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/test/DummyHttpServer.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/test/DummyHttpServer.java
new file mode 100644
index 00000000..e565c786
--- /dev/null
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/test/DummyHttpServer.java
@@ -0,0 +1,88 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.rest.services.adapters.http.test;
+
+import io.vavr.CheckedFunction0;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.function.Consumer;
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Mono;
+import reactor.netty.DisposableServer;
+import reactor.netty.http.server.HttpServer;
+import reactor.netty.http.server.HttpServerResponse;
+import reactor.netty.http.server.HttpServerRoutes;
+
+/**
+ * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
+ * @since February 2019
+ */
+public class DummyHttpServer {
+
+    private final DisposableServer server;
+
+    private DummyHttpServer(DisposableServer server) {
+        this.server = server;
+    }
+
+    public static DummyHttpServer start(Consumer<HttpServerRoutes> routes) {
+        return new DummyHttpServer(HttpServer.create()
+                .host("127.0.0.1")
+                .route(routes)
+                .bind()
+                .block());
+    }
+
+    public static Publisher<Void> sendResource(HttpServerResponse httpServerResponse, String resourcePath) {
+        return sendString(httpServerResponse, Mono.fromCallable(() -> readResource(resourcePath)));
+    }
+
+    public static Publisher<Void> sendString(HttpServerResponse httpServerResponse, Publisher<String> content) {
+        return httpServerResponse.sendString(content);
+    }
+
+    public void close() {
+        server.disposeNow();
+    }
+
+    public String host() {
+        return server.host();
+    }
+
+    public int port() {
+        return server.port();
+    }
+
+    private static String readResource(String resourcePath) {
+        try {
+            return CheckedFunction0.constant(resourcePath)
+                    .andThen(DummyHttpServer.class::getResource)
+                    .andThen(URL::toURI)
+                    .andThen(Paths::get)
+                    .andThen(Files::readAllBytes)
+                    .andThen(String::new)
+                    .apply();
+        } catch (Throwable throwable) {
+            throw new RuntimeException(throwable);
+        }
+    }
+}