Add request temp file buffer (#3479)

docs/modules/ROOT/partials/_configprops.adoc

@@ -3,7 +3,7 @@
 
 |spring.cloud.gateway.default-filters |  | List of filter definitions that are applied to every route.
 |spring.cloud.gateway.discovery.locator.enabled | `+++false+++` | Flag that enables DiscoveryClient gateway integration.
-|spring.cloud.gateway.discovery.locator.filters |  | 
+|spring.cloud.gateway.discovery.locator.filters |  |
 |spring.cloud.gateway.discovery.locator.include-expression | `+++true+++` | SpEL expression that will evaluate whether to include a service in gateway integration or not, defaults to: true.
 |spring.cloud.gateway.discovery.locator.lower-case-service-id | `+++false+++` | Option to lower case serviceId in predicates and filters, defaults to false. Useful with eureka when it automatically uppercases serviceId. so MYSERIVCE, would match /myservice/**
 |spring.cloud.gateway.discovery.locator.predicates |  | 
@@ -130,6 +130,8 @@
 |spring.cloud.gateway.mvc.routes-map |  | Map of Routes.
 |spring.cloud.gateway.mvc.streaming-buffer-size | `+++16384+++` | Buffer size for streaming media mime-types.
 |spring.cloud.gateway.mvc.streaming-media-types |  | Mime-types that are streaming.
+|spring.cloud.gateway.mvc.file-buffer-enabled | true | Enables the temp file buffer.
+|spring.cloud.gateway.mvc.file-buffer-size-threshold | 1MB | The size threshold which a request will be written to disk.
 |spring.cloud.gateway.mvc.transfer-encoding-normalization-request-headers-filter.enabled | `+++true+++` | Enables the transfer-encoding-normalization-request-headers-filter.
 |spring.cloud.gateway.mvc.weight-calculator-filter.enabled | `+++true+++` | Enables the weight-calculator-filter.
 |spring.cloud.gateway.mvc.x-forwarded-request-headers-filter.enabled | `+++true+++` | If the XForwardedHeadersFilter is enabled.

spring-cloud-gateway-server-mvc/src/main/java/org/springframework/cloud/gateway/server/mvc/common/AbstractProxyExchange.java

@@ -75,4 +75,9 @@ private int copyResponseBodyWithFlushing(InputStream inputStream, OutputStream o
 		return totalReadBytes;
 	}
 
+
+	protected boolean isWriteClientBodyToFile(Request request) {
+		return properties.isFileBufferEnabled() && request.getServerRequest().servletRequest().getContentLength() >= properties.getFileBufferSizeThreshold().toBytes();
+	}
+
 }

spring-cloud-gateway-server-mvc/src/main/java/org/springframework/cloud/gateway/server/mvc/common/MvcUtils.java

@@ -17,6 +17,7 @@
 package org.springframework.cloud.gateway.server.mvc.common;
 
 import java.io.ByteArrayInputStream;
+import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.UncheckedIOException;
@@ -92,6 +93,11 @@ public abstract class MvcUtils {
 	 */
 	public static final String WEIGHT_ATTR = qualify("routeWeight");
 
+	/**
+	 * Client request body temp file.
+	 */
+	public static final String CLIENT_BODY_TMP_ATTR = qualify("clientBodyTempFile");
+
 	private MvcUtils() {
 	}
 
@@ -242,6 +248,12 @@ public static void setRequestUrl(ServerRequest request, URI url) {
 		request.servletRequest().setAttribute(GATEWAY_REQUEST_URL_ATTR, url);
 	}
 
+	public static void setBodyTempFile(ServerRequest request, File file) {
+		request.attributes().put(GATEWAY_ROUTE_ID_ATTR, file);
+		request.servletRequest().setAttribute(GATEWAY_ROUTE_ID_ATTR, file);
+	}
+
+
 	private record ByteArrayInputMessage(ServerRequest request, ByteArrayInputStream body) implements HttpInputMessage {
 
 		@Override

spring-cloud-gateway-server-mvc/src/main/java/org/springframework/cloud/gateway/server/mvc/config/GatewayMvcProperties.java

@@ -29,6 +29,7 @@
 import org.springframework.boot.context.properties.DeprecatedConfigurationProperty;
 import org.springframework.core.style.ToStringCreator;
 import org.springframework.http.MediaType;
+import org.springframework.util.unit.DataSize;
 
 @ConfigurationProperties(GatewayMvcProperties.PREFIX)
 public class GatewayMvcProperties {
@@ -66,6 +67,16 @@ public class GatewayMvcProperties {
 	 */
 	private int streamingBufferSize = 16384;
 
+	/**
+	 * Temp file buffer for request.
+	 */
+	private boolean fileBufferEnabled = true;
+
+	/**
+	 * The size threshold which a request will be written to disk.
+	 */
+	private DataSize fileBufferSizeThreshold =  DataSize.ofMegabytes(1L);
+
 	public List<RouteProperties> getRoutes() {
 		return routes;
 	}
@@ -102,13 +113,31 @@ public void setStreamingBufferSize(int streamingBufferSize) {
 		this.streamingBufferSize = streamingBufferSize;
 	}
 
+	public boolean isFileBufferEnabled() {
+		return fileBufferEnabled;
+	}
+
+	public void setFileBufferEnabled(boolean fileBufferEnabled) {
+		this.fileBufferEnabled = fileBufferEnabled;
+	}
+
+	public DataSize getFileBufferSizeThreshold() {
+		return fileBufferSizeThreshold;
+	}
+
+	public void setFileBufferSizeThreshold(DataSize fileBufferSizeThreshold) {
+		this.fileBufferSizeThreshold = fileBufferSizeThreshold;
+	}
+
 	@Override
 	public String toString() {
 		return new ToStringCreator(this).append("httpClient", httpClient)
 			.append("routes", routes)
 			.append("routesMap", routesMap)
 			.append("streamingMediaTypes", streamingMediaTypes)
 			.append("streamingBufferSize", streamingBufferSize)
+			.append("fileBufferEnabled", fileBufferEnabled)
+			.append("fileBufferSizeThreshold", fileBufferSizeThreshold)
 			.toString();
 	}
 

spring-cloud-gateway-server-mvc/src/main/java/org/springframework/cloud/gateway/server/mvc/handler/RestClientProxyExchange.java

@@ -16,14 +16,18 @@
 
 package org.springframework.cloud.gateway.server.mvc.handler;
 
+import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.UncheckedIOException;
+import java.nio.file.Files;
+import java.nio.file.StandardCopyOption;
 
 import org.springframework.cloud.gateway.server.mvc.common.AbstractProxyExchange;
 import org.springframework.cloud.gateway.server.mvc.common.MvcUtils;
 import org.springframework.cloud.gateway.server.mvc.config.GatewayMvcProperties;
+import org.springframework.core.io.FileSystemResource;
 import org.springframework.http.client.ClientHttpResponse;
 import org.springframework.util.StreamUtils;
 import org.springframework.web.client.RestClient;
@@ -50,9 +54,25 @@ public ServerResponse exchange(Request request) {
 			.uri(request.getUri())
 			.headers(httpHeaders -> httpHeaders.putAll(request.getHeaders()));
 		if (isBodyPresent(request)) {
-			requestSpec.body(outputStream -> copyBody(request, outputStream));
+			if (isWriteClientBodyToFile(request)) {
+				requestSpec.body(copyClientBodyToFile(request));
+			}
+			else {
+				requestSpec.body(outputStream -> copyBody(request, outputStream));
+			}
+		}
+		return requestSpec.exchange((clientRequest, clientResponse) -> {
+			ServerResponse serverResponse = doExchange(request, clientResponse);
+			clearTempFileIfExist(request);
+			return serverResponse;
+		}, false);
+	}
+
+	private void clearTempFileIfExist(Request request) {
+		File tempFile = MvcUtils.getAttribute(request.getServerRequest(), MvcUtils.CLIENT_BODY_TMP_ATTR);
+		if (tempFile != null && tempFile.exists()) {
+			tempFile.delete();
 		}
-		return requestSpec.exchange((clientRequest, clientResponse) -> doExchange(request, clientResponse), false);
 	}
 
 	private static boolean isBodyPresent(Request request) {
@@ -68,6 +88,23 @@ private static int copyBody(Request request, OutputStream outputStream) throws I
 		return StreamUtils.copy(request.getServerRequest().servletRequest().getInputStream(), outputStream);
 	}
 
+	private static FileSystemResource copyClientBodyToFile(Request request) {
+		File bodyTempFile = null;
+		try {
+			// TODO: customize temp dir
+			bodyTempFile = File.createTempFile("gateway_client_body", ".tmp");
+			Files.copy(request.getServerRequest().servletRequest().getInputStream(), bodyTempFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
+		}
+		catch (IOException e) {
+			if (bodyTempFile != null && bodyTempFile.exists()) {
+				bodyTempFile.delete();
+			}
+			throw new UncheckedIOException(e);
+		}
+		MvcUtils.setBodyTempFile(request.getServerRequest(), bodyTempFile);
+		return new FileSystemResource(bodyTempFile);
+	}
+
 	private ServerResponse doExchange(Request request, ClientHttpResponse clientResponse) throws IOException {
 		InputStream body = clientResponse.getBody();
 		// put the body input stream in a request attribute so filters can read it.