Implement x-prebid headers support

src/main/java/org/prebid/server/bidder/HttpBidderRequestEnricher.java

@@ -0,0 +1,82 @@
+package org.prebid.server.bidder;
+
+import com.iab.openrtb.request.App;
+import com.iab.openrtb.request.BidRequest;
+import io.vertx.core.MultiMap;
+import org.apache.commons.lang3.StringUtils;
+import org.prebid.server.proto.openrtb.ext.request.ExtApp;
+import org.prebid.server.proto.openrtb.ext.request.ExtAppPrebid;
+import org.prebid.server.proto.openrtb.ext.request.ExtRequest;
+import org.prebid.server.proto.openrtb.ext.request.ExtRequestPrebid;
+import org.prebid.server.proto.openrtb.ext.request.ExtRequestPrebidChannel;
+import org.prebid.server.util.HttpUtil;
+
+import java.util.Collections;
+import java.util.Objects;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class HttpBidderRequestEnricher {
+
+    private static final Set<CharSequence> HEADERS_TO_COPY = Collections.singleton(HttpUtil.SEC_GPC_HEADER.toString());
+
+    private final String pbsRecord;
+
+    public HttpBidderRequestEnricher(String pbsVersion) {
+        this.pbsRecord = createNameVersionRecord("pbs-java", Objects.requireNonNull(pbsVersion));
+    }
+
+    MultiMap enrichHeaders(MultiMap bidderRequestHeaders, MultiMap originalRequestHeaders, BidRequest bidRequest) {
+        // some bidders has headers on class level, so we create copy to not affect them
+        final MultiMap bidderRequestHeadersCopy = copyMultiMap(bidderRequestHeaders);
+
+        originalRequestHeaders.entries().stream()
+                .filter(entry -> HEADERS_TO_COPY.contains(entry.getKey())
+                        && !bidderRequestHeadersCopy.contains(entry.getKey()))
+                .forEach(entry -> bidderRequestHeadersCopy.add(entry.getKey(), entry.getValue()));
+        addXPrebidHeader(bidderRequestHeadersCopy, bidRequest);
+        return bidderRequestHeadersCopy;
+    }
+
+    private static MultiMap copyMultiMap(MultiMap source) {
+        final MultiMap copiedMultiMap = MultiMap.caseInsensitiveMultiMap();
+        if (source != null && !source.isEmpty()) {
+            source.forEach(entry -> copiedMultiMap.add(entry.getKey(), entry.getValue()));
+        }
+        return copiedMultiMap;
+    }
+
+    private void addXPrebidHeader(MultiMap headers, BidRequest bidRequest) {
+        final String channelRecord = resolveChannelVersionRecord(bidRequest.getExt());
+        final String sdkRecord = resolveSdkVersionRecord(bidRequest.getApp());
+        final String value = Stream.of(channelRecord, sdkRecord, pbsRecord)
+                .filter(Objects::nonNull)
+                .collect(Collectors.joining(","));
+        HttpUtil.addHeaderIfValueIsNotEmpty(headers, HttpUtil.X_PREBID_HEADER, value);
+    }
+
+    private static String resolveChannelVersionRecord(ExtRequest extRequest) {
+        final ExtRequestPrebid extPrebid = extRequest != null ? extRequest.getPrebid() : null;
+        final ExtRequestPrebidChannel channel = extPrebid != null ? extPrebid.getChannel() : null;
+        final String channelName = channel != null ? channel.getName() : null;
+        final String channelVersion = channel != null ? channel.getVersion() : null;
+
+        return createNameVersionRecord(channelName, channelVersion);
+    }
+
+    private static String resolveSdkVersionRecord(App app) {
+        final ExtApp extApp = app != null ? app.getExt() : null;
+        final ExtAppPrebid extPrebid = extApp != null ? extApp.getPrebid() : null;
+        final String sdkSource = extPrebid != null ? extPrebid.getSource() : null;
+        final String sdkVersion = extPrebid != null ? extPrebid.getVersion() : null;
+
+        return createNameVersionRecord(sdkSource, sdkVersion);
+    }
+
+    private static String createNameVersionRecord(String name, String version) {
+        return StringUtils.isNotEmpty(name) && StringUtils.isNotEmpty(version)
+                ? String.format("%s/%s", name, version)
+                : null;
+    }
+}

src/main/java/org/prebid/server/bidder/HttpBidderRequester.java

@@ -5,7 +5,6 @@
 import io.netty.handler.codec.http.HttpResponseStatus;
 import io.vertx.core.CompositeFuture;
 import io.vertx.core.Future;
-import io.vertx.core.MultiMap;
 import io.vertx.core.logging.Logger;
 import io.vertx.core.logging.LoggerFactory;
 import io.vertx.ext.web.RoutingContext;
@@ -22,7 +21,6 @@
 import org.prebid.server.bidder.model.Result;
 import org.prebid.server.execution.Timeout;
 import org.prebid.server.proto.openrtb.ext.response.ExtHttpCall;
-import org.prebid.server.util.HttpUtil;
 import org.prebid.server.vertx.http.HttpClient;
 import org.prebid.server.vertx.http.model.HttpClientResponse;
 
@@ -32,7 +30,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Set;
 import java.util.concurrent.TimeoutException;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -50,19 +47,20 @@ public class HttpBidderRequester {
 
     private static final Logger logger = LoggerFactory.getLogger(HttpBidderRequester.class);
 
-    private static final Set<CharSequence> HEADERS_TO_COPY = Collections.singleton(HttpUtil.SEC_GPC.toString());
-
     private final HttpClient httpClient;
     private final BidderRequestCompletionTrackerFactory completionTrackerFactory;
     private final BidderErrorNotifier bidderErrorNotifier;
+    private final HttpBidderRequestEnricher requestEnricher;
 
     public HttpBidderRequester(HttpClient httpClient,
                                BidderRequestCompletionTrackerFactory completionTrackerFactory,
-                               BidderErrorNotifier bidderErrorNotifier) {
+                               BidderErrorNotifier bidderErrorNotifier,
+                               HttpBidderRequestEnricher requestEnricher) {
 
         this.httpClient = Objects.requireNonNull(httpClient);
         this.completionTrackerFactory = completionTrackerFactoryOrFallback(completionTrackerFactory);
         this.bidderErrorNotifier = Objects.requireNonNull(bidderErrorNotifier);
+        this.requestEnricher = Objects.requireNonNull(requestEnricher);
     }
 
     /**
@@ -77,7 +75,8 @@ public <T> Future<BidderSeatBid> requestBids(Bidder<T> bidder,
 
         final Result<List<HttpRequest<T>>> httpRequestsWithErrors = bidder.makeHttpRequests(bidRequest);
         final List<BidderError> bidderErrors = httpRequestsWithErrors.getErrors();
-        final List<HttpRequest<T>> httpRequests = enrichRequests(httpRequestsWithErrors.getValue(), routingContext);
+        final List<HttpRequest<T>> httpRequests =
+                enrichRequests(httpRequestsWithErrors.getValue(), routingContext, bidRequest);
 
         if (CollectionUtils.isEmpty(httpRequests)) {
             return emptyBidderSeatBidWithErrors(bidderErrors);
@@ -108,34 +107,16 @@ public <T> Future<BidderSeatBid> requestBids(Bidder<T> bidder,
                 .map(ignored -> resultBuilder.toBidderSeatBid(debugEnabled));
     }
 
-    private static <T> List<HttpRequest<T>> enrichRequests(List<HttpRequest<T>> httpRequests,
-                                                           RoutingContext routingContext) {
-
+    private <T> List<HttpRequest<T>> enrichRequests(List<HttpRequest<T>> httpRequests,
+                                                    RoutingContext routingContext,
+                                                    BidRequest bidRequest) {
         return httpRequests.stream().map(httpRequest -> httpRequest.toBuilder()
-                .headers(enrichHeaders(httpRequest.getHeaders(), routingContext.request().headers()))
+                .headers(requestEnricher.enrichHeaders(httpRequest.getHeaders(),
+                        routingContext.request().headers(), bidRequest))
                 .build())
                 .collect(Collectors.toList());
     }
 
-    private static MultiMap enrichHeaders(MultiMap bidderRequestHeaders, MultiMap originalRequestHeaders) {
-        // some bidders has headers on class level, so we create copy to not affect them
-        final MultiMap bidderRequestHeadersCopy = copyMultiMap(bidderRequestHeaders);
-
-        originalRequestHeaders.entries().stream()
-                .filter(entry -> HEADERS_TO_COPY.contains(entry.getKey())
-                        && !bidderRequestHeadersCopy.contains(entry.getKey()))
-                .forEach(entry -> bidderRequestHeadersCopy.add(entry.getKey(), entry.getValue()));
-        return bidderRequestHeadersCopy;
-    }
-
-    private static MultiMap copyMultiMap(MultiMap source) {
-        final MultiMap copiedMultiMap = MultiMap.caseInsensitiveMultiMap();
-        if (source != null && !source.isEmpty()) {
-            source.forEach(entry -> copiedMultiMap.add(entry.getKey(), entry.getValue()));
-        }
-        return copiedMultiMap;
-    }
-
     private <T> boolean isStoredResponse(List<HttpRequest<T>> httpRequests, String storedResponse, String bidder) {
         if (StringUtils.isBlank(storedResponse)) {
             return false;

src/main/java/org/prebid/server/spring/config/ServiceConfiguration.java

@@ -32,6 +32,7 @@
 import org.prebid.server.bidder.BidderDeps;
 import org.prebid.server.bidder.BidderErrorNotifier;
 import org.prebid.server.bidder.BidderRequestCompletionTrackerFactory;
+import org.prebid.server.bidder.HttpBidderRequestEnricher;
 import org.prebid.server.bidder.HttpBidderRequester;
 import org.prebid.server.cache.CacheService;
 import org.prebid.server.cache.model.CacheTtl;
@@ -462,9 +463,19 @@ BidderCatalog bidderCatalog(List<BidderDeps> bidderDeps) {
     HttpBidderRequester httpBidderRequester(
             HttpClient httpClient,
             @Autowired(required = false) BidderRequestCompletionTrackerFactory bidderRequestCompletionTrackerFactory,
-            BidderErrorNotifier bidderErrorNotifier) {
+            BidderErrorNotifier bidderErrorNotifier,
+            HttpBidderRequestEnricher requestEnricher) {
 
-        return new HttpBidderRequester(httpClient, bidderRequestCompletionTrackerFactory, bidderErrorNotifier);
+        return new HttpBidderRequester(httpClient,
+                bidderRequestCompletionTrackerFactory,
+                bidderErrorNotifier,
+                requestEnricher);
+    }
+
+    @Bean
+    HttpBidderRequestEnricher httpBidderRequestEnricher(VersionInfo versionInfo) {
+
+        return new HttpBidderRequestEnricher(versionInfo.getVersion());
     }
 
     @Bean

src/main/java/org/prebid/server/util/HttpUtil.java

@@ -32,7 +32,7 @@ public final class HttpUtil {
     public static final CharSequence X_REQUEST_AGENT_HEADER = HttpHeaders.createOptimized("X-Request-Agent");
     public static final CharSequence ORIGIN_HEADER = HttpHeaders.createOptimized("Origin");
     public static final CharSequence ACCEPT_HEADER = HttpHeaders.createOptimized("Accept");
-    public static final CharSequence SEC_GPC = HttpHeaders.createOptimized("Sec-GPC");
+    public static final CharSequence SEC_GPC_HEADER = HttpHeaders.createOptimized("Sec-GPC");
     public static final CharSequence CONTENT_TYPE_HEADER = HttpHeaders.createOptimized("Content-Type");
     public static final CharSequence X_REQUESTED_WITH_HEADER = HttpHeaders.createOptimized("X-Requested-With");
     public static final CharSequence REFERER_HEADER = HttpHeaders.createOptimized("Referer");
@@ -49,6 +49,7 @@ public final class HttpUtil {
     public static final CharSequence CONNECTION_HEADER = HttpHeaders.createOptimized("Connection");
     public static final CharSequence ACCEPT_ENCODING_HEADER = HttpHeaders.createOptimized("Accept-Encoding");
     public static final CharSequence X_OPENRTB_VERSION_HEADER = HttpHeaders.createOptimized("x-openrtb-version");
+    public static final CharSequence X_PREBID_HEADER = HttpHeaders.createOptimized("x-prebid");
 
     private HttpUtil() {
     }

src/test/java/org/prebid/server/bidder/HttpBidderRequestEnricherTest.java

@@ -0,0 +1,103 @@
+package org.prebid.server.bidder;
+
+import com.iab.openrtb.request.App;
+import com.iab.openrtb.request.BidRequest;
+import io.vertx.core.MultiMap;
+import io.vertx.core.http.CaseInsensitiveHeaders;
+import org.junit.Before;
+import org.junit.Test;
+import org.prebid.server.proto.openrtb.ext.request.ExtApp;
+import org.prebid.server.proto.openrtb.ext.request.ExtAppPrebid;
+import org.prebid.server.proto.openrtb.ext.request.ExtRequest;
+import org.prebid.server.proto.openrtb.ext.request.ExtRequestPrebid;
+import org.prebid.server.proto.openrtb.ext.request.ExtRequestPrebidChannel;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class HttpBidderRequestEnricherTest {
+
+    private HttpBidderRequestEnricher requestEnricher;
+
+    @Before
+    public void setUp() {
+
+        requestEnricher = new HttpBidderRequestEnricher("1.00");
+    }
+
+    @Test
+    public void shouldSendPopulatedPostRequest() {
+        // given
+        final MultiMap headers = new CaseInsensitiveHeaders();
+        headers.add("header1", "value1");
+        headers.add("header2", "value2");
+
+        // when
+        final MultiMap resultHeaders =
+                requestEnricher.enrichHeaders(headers, new CaseInsensitiveHeaders(), BidRequest.builder().build());
+
+        // then
+        final MultiMap expectedHeaders = new CaseInsensitiveHeaders();
+        expectedHeaders.addAll(headers);
+        expectedHeaders.add("x-prebid", "pbs-java/1.00");
+        assertThat(resultHeaders).hasSize(3);
+        assertThat(isEqualsMultiMaps(resultHeaders, expectedHeaders)).isTrue();
+    }
+
+    @Test
+    public void shouldAddSecGpcHeaderFromOriginalRequest() {
+        // given
+        final MultiMap originalHeaders = new CaseInsensitiveHeaders().add("Sec-GPC", "1");
+
+        // when
+        final MultiMap resultHeaders =
+                requestEnricher.enrichHeaders(new CaseInsensitiveHeaders(),
+                        originalHeaders, BidRequest.builder().build());
+
+        // then
+        assertThat(resultHeaders.contains("Sec-GPC")).isTrue();
+        assertThat(resultHeaders.get("Sec-GPC")).isEqualTo("1");
+    }
+
+    @Test
+    public void shouldNotOverrideHeadersFromBidRequest() {
+        // given
+        final MultiMap originalHeaders = new CaseInsensitiveHeaders().add("Sec-GPC", "1");
+        final MultiMap bidderRequestHeaders = new CaseInsensitiveHeaders().add("Sec-GPC", "0");
+
+        // when
+        final MultiMap resultHeaders = requestEnricher.enrichHeaders(bidderRequestHeaders,
+                originalHeaders, BidRequest.builder().build());
+
+        // then
+        assertThat(resultHeaders.contains("Sec-GPC")).isTrue();
+        assertThat(resultHeaders.getAll("Sec-GPC")).hasSize(1);
+        assertThat(resultHeaders.get("Sec-GPC")).isEqualTo("0");
+    }
+
+    @Test
+    public void shouldCreateXPrebidHeaderForOutgoingRequest() {
+        // given
+        final BidRequest bidRequest = BidRequest.builder()
+                .ext(ExtRequest.of(ExtRequestPrebid.builder()
+                        .channel(ExtRequestPrebidChannel.of("pbjs", "4.39"))
+                        .build()))
+                .app(App.builder()
+                        .ext(ExtApp.of(ExtAppPrebid.of("prebid-mobile", "1.2.3"), null))
+                        .build())
+                .build();
+
+        // when
+        final MultiMap resultHeaders = requestEnricher.enrichHeaders(new CaseInsensitiveHeaders(),
+                new CaseInsensitiveHeaders(), bidRequest);
+
+        // then
+        final MultiMap expectedHeaders = new CaseInsensitiveHeaders();
+        expectedHeaders.add("x-prebid", "pbjs/4.39,prebid-mobile/1.2.3,pbs-java/1.00");
+        assertThat(isEqualsMultiMaps(resultHeaders, expectedHeaders)).isTrue();
+    }
+
+    private static boolean isEqualsMultiMaps(MultiMap left, MultiMap right) {
+        return left.size() == right.size() && left.entries().stream()
+                .allMatch(entry -> right.contains(entry.getKey(), entry.getValue(), true));
+    }
+}