When you update the rancher credentials for the private docker registry.

Rancher has a really heavy cache for the credentials

and sometimes it takes forever to update to the new credentials

Force the update credentials

• Edit the node
• Point to a docker image that not exist in your registry
• Save the changes go back and scale to 1 node or 2
• When you see the error that the docker image is not found, scale back to 0 nodes
• Edit the node and point to the correct image tag or version
• Save the changes
• Update the nodes to 1, so you can see if the Rancher is pulling the images from the right registry

• After this you can check if she is working or not

• Helpful links
  Rancher Documentation