Resolves the remote ip when behind proxy; fixes gh-1683

Author: marcingrzejszczak

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/web/TraceWebFilter.java

@@ -330,6 +330,14 @@ public ServerHttpRequest unwrap() {
 
 		@Override
 		public boolean parseClientIpAndPort(Span span) {
+			boolean clientIpAndPortParsed = super.parseClientIpAndPort(span);
+			if (clientIpAndPortParsed) {
+				return true;
+			}
+			return resolveFromInetAddress(span);
+		}
+
+		private boolean resolveFromInetAddress(Span span) {
 			InetSocketAddress addr = delegate.getRemoteAddress();
 			if (addr == null) {
 				return false;

tests/spring-cloud-sleuth-instrumentation-feign-tests/src/test/java/org/springframework/cloud/sleuth/instrument/feign/issues/issue502/Issue502Tests.java

@@ -82,7 +82,7 @@ public void should_reuse_custom_feign_client() {
 		then(response).isEqualTo("foo");
 		// retries
 		then(this.spans).hasSize(1);
-		//then(this.spans.get(0).tags().get("http.path")).isEqualTo("");
+		// then(this.spans.get(0).tags().get("http.path")).isEqualTo("");
 	}
 
 }

tests/spring-cloud-sleuth-instrumentation-webflux-tests/src/test/java/org/springframework/cloud/sleuth/instrument/web/TraceWebFluxTests.java

@@ -93,6 +93,11 @@ public void should_instrument_web_filter() throws Exception {
 		// then
 		thenNoSpanWasReported(spans, skippedPatternResponse, controller2);
 
+		// when (issue #1683)
+		response = whenRequestWithXForwardedForIsSent(port, "/api/fn/20");
+		// then
+		thenSpanWasReportedWithRemoteIpTags(spans, response);
+
 		// cleanup
 		context.close();
 	}
@@ -110,6 +115,15 @@ private void thenSpanWasReportedWithTags(TestSpanHandler spans,
 		then(spans.get(0).name()).isEqualTo("GET /api/c2/{id}");
 		then(spans.get(0).tags()).containsEntry("mvc.controller.method", "successful")
 				.containsEntry("mvc.controller.class", "Controller2");
+		then(spans.get(0).remoteIp()).isEqualTo("127.0.0.1");
+	}
+
+	private void thenSpanWasReportedWithRemoteIpTags(TestSpanHandler spans,
+			ClientResponse response) {
+		Awaitility.await()
+				.untilAsserted(() -> then(response.statusCode().value()).isEqualTo(200));
+		then(spans).hasSize(1);
+		then(spans.get(0).remoteIp()).isEqualTo("203.0.113.195");
 	}
 
 	private void thenFunctionalSpanWasReportedWithTags(TestSpanHandler spans,
@@ -138,6 +152,14 @@ private ClientResponse whenRequestIsSent(int port, String path) {
 		return exchange.block();
 	}
 
+	private ClientResponse whenRequestWithXForwardedForIsSent(int port, String path) {
+		Mono<ClientResponse> exchange = WebClient.create().get()
+				.uri("http://localhost:" + port + path)
+				.header("X-Forwarded-For", "203.0.113.195, 70.41.3.18, 150.172.238.178")
+				.exchange();
+		return exchange.block();
+	}
+
 	private ClientResponse whenRequestIsSentToSkippedPattern(int port) {
 		Mono<ClientResponse> exchange = WebClient.create().get()
 				.uri("http://localhost:" + port + "/skipped").exchange();