Enable HTTP/2 support in kube-client rustls connector

This change adds HTTP/2 ALPN support to the rustls HTTPS connector by
calling enable_http2() in addition to enable_http1(). This enables
HTTP/2 multiplexing for Kubernetes API connections, reducing the
number of TCP connections from potentially hundreds to a single
multiplexed connection per API server.

Previously, kube-rs only supported HTTP/1.1 connections, resulting in
a new TCP connection for each concurrent API request. With HTTP/2
enabled, multiple requests can be multiplexed over a single connection,
improving performance and reducing resource usage.

Signed-off-by: Andrew McDermott <[email protected]>

Author: frobware

kube-client/src/client/config_ext.rs

@@ -245,7 +245,7 @@ impl ConfigExt for Config {
                     .map_err(Error::RustlsTls)?,
             ));
         }
-        Ok(builder.enable_http1().wrap_connector(connector))
+        Ok(builder.enable_http1().enable_http2().wrap_connector(connector))
     }
 
     #[cfg(feature = "openssl-tls")]