Maybe I didn’t search hard enough here to find this, but I was having issue getting images to pull from a private docker registry that has a self signed certificate. The rancher documentation for the host setup was not the fix I needed. Turns out the docker documentation here described the fix. Just wanted to point that out in case anyone else is about to travel down the same rabbit hole I just did.
Here’s the docs that we have for Rancher, but basically, it’s as you described, you need to set up your docker daemon as you described
http://docs.rancher.com/rancher/configuration/registries/#self-signed-certificates