kubelet/client: collapse transport wiring onto standard approach

Signed-off-by: Monis Khan <[email protected]>

Kubernetes-commit: c651e4f7da1c43ddd956fbba303e990d6f27130a

Author: enj

transport/cache.go

@@ -109,7 +109,7 @@ func (c *tlsTransportCache) get(config *Config) (http.RoundTripper, error) {
 
 	// If we use are reloading files, we need to handle certificate rotation properly
 	// TODO(jackkleeman): We can also add rotation here when config.HasCertCallback() is true
-	if config.TLS.ReloadTLSFiles {
+	if config.TLS.ReloadTLSFiles && tlsConfig != nil && tlsConfig.GetClientCertificate != nil {
 		dynamicCertDialer := certRotatingDialer(tlsConfig.GetClientCertificate, dial)
 		tlsConfig.GetClientCertificate = dynamicCertDialer.GetClientCertificate
 		dial = dynamicCertDialer.connDialer.DialContext