Hi Ankush:
Yes . Stx has ansible variant  cluster_pod_subnet to config the subnet of k8s cluster .
please check [1] for it. 
Thanks.
BR
Austin Sun. 
From: Rai, Ankush <Ankush.Rai@commscope.com> 
Sent: Friday, August 28, 2020 2:46 AM
To: starlingx-discuss@lists.starlingx.io
Subject: [Starlingx-discuss] How to change docker default subnet?
Is there any Ansible configuration or CLI to redefine the docker subnet ? 
This default subnet 172.17.
 0.0/16 is clashing with LAB network and I am not able to access the StarlingX cluster from LAB network.
Is it feasible to use "bip" option in "/etc/docker/daemon.json" ?
Thanks,
Ankush