HELP: How do I get docker TLS to work?

I’m (desperately) trying to get rancher to connect to my (RHEL) docker host using using TLS certificates, and cannot find the “official way”. If I manually edit the rancher/agent image by putting keys, cert, and ca.crt in /root/.docker/, add export DOCKER_TLS_VERIFY=1 to both / and /root/.profile I can get “docker ps” to not hang when I get into the container. (Though I still have issues).

Can anybody give me a hint as to how to setup rancher to work with docker TLS? I cannot find documentation, though I can see how to enable this on rancherOS, or the web server for rancher.

Edit: This looks like it is as simple as either 1) getting the variable DOCKER_TLS_VERIFY set in child containers or 2) finding the built-in setting for host TLS (which I cannot find)!!