Expose network interfaces via runc events

The libcontainer network statistics are unreachable without manually
creating a libcontainer instance. To retrieve them via the CLI interface
of runc, we now expose them as well.

Signed-off-by: Sascha Grunert <sgrunert@suse.com>

events.go

@@ -163,6 +163,7 @@ func convertLibcontainerStats(ls *libcontainer.Stats) *types.Stats {
 		}
 	}
 
+	s.NetworkInterfaces = ls.Interfaces
 	return &s
 }