Updating proxy setting in rancher 2 HA on RKE/rancheros


I need to update the proxy setting for a rancher 2 HA cluster on RKE/rancherOS.
When i try to connect to my local vsphere instance Rancher do it via the proxy and that fail.

Which proxy setting are used? the docker one? or somewhere else?

Thanks for you help,

Rancher uses environment variables to set the proxy.