RancherOs add internal CA chain

I’m running RancherOs v1.6.10 and when attempting to docker login/pull from my private registry signed by an internal CA authority I get a “x509: certificate signed by unknown authority” error. How do I add the CA certchain to ROS? Googling got me here so it looks like it’s a feature that has not been implemented. If this is true is there a way to get this done in an “unsupported” way?