Merge pull request #5139 from Stono/master

Fixes https://github.com/kubernetes/ingress-nginx/issues/5120

rootfs/etc/nginx/template/nginx.tmpl

@@ -856,6 +856,11 @@ stream {
         location = {{ $authPath }} {
             internal;
 
+						{{ if $all.Cfg.EnableOpentracing }}
+            opentracing on; 
+            opentracing_propagate_context;
+            {{ end }}
+
             {{ if $externalAuth.AuthCacheKey }}
             set $tmp_cache_key '{{ $server.Hostname }}{{ $authPath }}{{ $externalAuth.AuthCacheKey }}';
             set $cache_key '';