[net] Expose Jetty EndPoint in http requests

bundles/org.openhab.core.io.net/src/main/java/org/openhab/core/io/net/http/internal/WebClientFactoryImpl.java

@@ -24,11 +24,20 @@
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.jetty.client.HttpClient;
+import org.eclipse.jetty.client.HttpDestination;
+import org.eclipse.jetty.client.HttpExchange;
 import org.eclipse.jetty.client.HttpProxy;
+import org.eclipse.jetty.client.api.Connection;
+import org.eclipse.jetty.client.http.HttpChannelOverHTTP;
+import org.eclipse.jetty.client.http.HttpClientTransportOverHTTP;
+import org.eclipse.jetty.client.http.HttpConnectionOverHTTP;
+import org.eclipse.jetty.client.http.HttpReceiverOverHTTP;
 import org.eclipse.jetty.http.HttpHeader;
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.http.PreEncodedHttpField;
 import org.eclipse.jetty.http2.client.HTTP2Client;
+import org.eclipse.jetty.io.EndPoint;
+import org.eclipse.jetty.util.Promise;
 import org.eclipse.jetty.util.ssl.SslContextFactory;
 import org.eclipse.jetty.util.thread.QueuedThreadPool;
 import org.eclipse.jetty.websocket.client.WebSocketClient;
@@ -235,7 +244,7 @@ private HttpClient createHttpClientInternal(String consumerName, @Nullable SslCo
         try {
             logger.debug("creating http client for consumer {}", consumerName);
 
-            HttpClient httpClient = new HttpClient(
+            HttpClient httpClient = new HttpClient(new CustomHttpClientTransportOverHTTP(),
                     sslContextFactory != null ? sslContextFactory : createSslContextFactory());
 
             // If proxy is set as property (standard Java property), provide the proxy information to Jetty HTTP
@@ -413,4 +422,48 @@ private HTTP2Client createHttp2ClientInternal(String consumerName, @Nullable Ssl
                     "unexpected checked exception during initialization of the Jetty HTTP/2 client", e);
         }
     }
+
+    /**
+     * Extends the default {@link HttpClientTransportOverHTTP) but exposes the underling {@link EndPoint} of each
+     * request/response.
+     * It mimics the way it's done in higher Jetty Http client versions.
+     */
+    private static class CustomHttpClientTransportOverHTTP extends HttpClientTransportOverHTTP {
+        @Override
+        @NonNullByDefault({})
+        protected HttpConnectionOverHTTP newHttpConnection(EndPoint endPoint, HttpDestination destination,
+                Promise<Connection> promise) {
+            return new HttpConnectionOverHTTP(endPoint, destination, promise) {
+                @Override
+                protected HttpChannelOverHTTP newHttpChannel() {
+                    return new HttpChannelOverHTTP(this) {
+                        @Override
+                        protected HttpReceiverOverHTTP newHttpReceiver() {
+                            return new CustomHttpReceiverOverHTTP(this);
+                        }
+                    };
+                }
+            };
+        }
+
+        private static class CustomHttpReceiverOverHTTP extends HttpReceiverOverHTTP {
+            private final HttpChannelOverHTTP channel;
+
+            public CustomHttpReceiverOverHTTP(HttpChannelOverHTTP channel) {
+                super(channel);
+                this.channel = channel;
+            }
+
+            @Override
+            public boolean headerComplete() {
+                HttpExchange exchange = getHttpExchange();
+                if (exchange != null) {
+                    // Store the EndPoint is case of upgrades
+                    exchange.getRequest().getConversation().setAttribute(EndPoint.class.getName(),
+                            channel.getHttpConnection().getEndPoint());
+                }
+                return super.headerComplete();
+            }
+        }
+    }
 }