ReactorNettyWebSocketClient WebSocket sub protocol handling broken in GatewayAutoConfiguration

[Johannes-Rost]

org.springframework.cloud.gateway.config.GatewayAutoConfiguration creates an instance of org.springframework.web.reactive.socket.client.ReactorNettyWebSocketClient with a reactor.netty.http.client.WebsocketClientSpec.Builder which is reused for multiple requests with different protocols.

This bug is almost the same as #2159 but for the WebSocketClient instead of the RequestUpgradeStrategy.

The bug was introduced in 3.0.x:

@Bean
@ConditionalOnEnabledGlobalFilter(WebsocketRoutingFilter.class)
public ReactorNettyWebSocketClient reactorNettyWebSocketClient(HttpClientProperties properties,
		HttpClient httpClient) {
	WebsocketClientSpec.Builder builder = WebsocketClientSpec.builder()
			.handlePing(properties.getWebsocket().isProxyPing());
	if (properties.getWebsocket().getMaxFramePayloadLength() != null) {
		builder.maxFramePayloadLength(properties.getWebsocket().getMaxFramePayloadLength());
	}
	return new ReactorNettyWebSocketClient(httpClient, builder);
 }

The WebsocketClientSpec.Builder implements Supplier<WebsocketClientSpec.Builder> but does not return a fresh instance when get() is invoked.

I will submit a pull request to fix this.

[spencergibb]

Closing in favor of #2216