container/init: configure interface lo

This enables loopback networking when owning the net namespace.

Signed-off-by: Ophestra <cat@gensokyo.uk>

container/init.go

@@ -170,6 +170,10 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 		offsetSetup = int(setupFd + 1)
 	}
 
+	if !params.HostNet {
+		k.mustLoopback(msg)
+	}
+
 	// write uid/gid map here so parent does not need to set dumpable
 	if err := k.setDumpable(SUID_DUMP_USER); err != nil {
 		k.fatalf(msg, "cannot set SUID_DUMP_USER: %v", err)