Make HttpClientProperties#proxy customizable

Fixes gh-2140

docs/src/main/asciidoc/_configprops.adoc

@@ -80,6 +80,7 @@
 |spring.cloud.gateway.httpclient.pool.max-life-time |  | Duration after which the channel will be closed. If NULL, there is no max life time.
 |spring.cloud.gateway.httpclient.pool.name | `proxy` | The channel pool map name, defaults to proxy.
 |spring.cloud.gateway.httpclient.pool.type |  | Type of pool for HttpClient to use, defaults to ELASTIC.
+|spring.cloud.gateway.httpclient.proxy.type | `HTTP` | proxyType for proxy configuration of Netty HttpClient.
 |spring.cloud.gateway.httpclient.proxy.host |  | Hostname for proxy configuration of Netty HttpClient.
 |spring.cloud.gateway.httpclient.proxy.non-proxy-hosts-pattern |  | Regular expression (Java) for a configured list of hosts. that should be reached directly, bypassing the proxy
 |spring.cloud.gateway.httpclient.proxy.password |  | Password for proxy configuration of Netty HttpClient.
@@ -140,4 +141,4 @@
 |spring.cloud.gateway.x-forwarded.proto-append | `true` | If appending X-Forwarded-Proto as a list is enabled.
 |spring.cloud.gateway.x-forwarded.proto-enabled | `true` | If X-Forwarded-Proto is enabled.
 
-|===
+|===

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

@@ -692,8 +692,7 @@ public class GatewayAutoConfiguration {
 						if (StringUtils.hasText(proxy.getHost())) {
 
 							tcpClient = tcpClient.proxy(proxySpec -> {
-								ProxyProvider.Builder builder = proxySpec.type(ProxyProvider.Proxy.HTTP)
-										.host(proxy.getHost());
+								ProxyProvider.Builder builder = proxySpec.type(proxy.getType()).host(proxy.getHost());
 
 								PropertyMapper map = PropertyMapper.get();
 

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

@@ -35,6 +35,7 @@ import javax.validation.constraints.Max;
 
 import reactor.netty.resources.ConnectionProvider;
 import reactor.netty.tcp.SslProvider;
+import reactor.netty.transport.ProxyProvider;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.web.server.WebServerException;
@@ -288,6 +289,9 @@ public class HttpClientProperties {
 
 	public static class Proxy {
 
+		/** proxyType for proxy configuration of Netty HttpClient. */
+		private ProxyProvider.Proxy type = ProxyProvider.Proxy.HTTP;
+
 		/** Hostname for proxy configuration of Netty HttpClient. */
 		private String host;
 
@@ -306,6 +310,14 @@ public class HttpClientProperties {
 		 */
 		private String nonProxyHostsPattern;
 
+		public ProxyProvider.Proxy getType() {
+			return type;
+		}
+
+		public void setType(ProxyProvider.Proxy type) {
+			this.type = type;
+		}
+
 		public String getHost() {
 			return host;
 		}
@@ -348,8 +360,9 @@ public class HttpClientProperties {
 
 		@Override
 		public String toString() {
-			return "Proxy{" + "host='" + host + '\'' + ", port=" + port + ", username='" + username + '\''
-					+ ", password='" + password + '\'' + ", nonProxyHostsPattern='" + nonProxyHostsPattern + '\'' + '}';
+			return "Proxy{" + "type='" + type + '\'' + "host='" + host + '\'' + ", port=" + port + ", username='"
+					+ username + '\'' + ", password='" + password + '\'' + ", nonProxyHostsPattern='"
+					+ nonProxyHostsPattern + '\'' + '}';
 		}
 
 	}