Regular Ubuntu upgrade moves docker to a not supported version

Rancher
1

On my test cluster: 3 RKE servers (Master + Node) and 1 Rancher server.

After an ubuntu upgrade, I got a not supported docker version.
The upgrade has no impact on the RKE cluster.

NAME           STATUS    ROLES                      AGE       VERSION   EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION      CONTAINER-RUNTIME
192.168.1.34   Ready     controlplane,etcd,worker   1d        v1.10.1   <none>        Ubuntu 16.04.4 LTS   4.13.0-45-generic   **docker://18.3.1**
192.168.1.39   Ready     controlplane,etcd,worker   1d        v1.10.1   <none>        Ubuntu 16.04.4 LTS   4.13.0-45-generic   docker://1.13.1
192.168.1.55   Ready     controlplane,etcd,worker   1d        v1.10.1   <none>        Ubuntu 16.04.4 LTS   4.4.0-128-generic   docker://17.3.2

I got docker version 18.3.1 not supported by Rancher.
If I like to install a new RKE version than the installation shall fail because of the docker version checks of the installation programs.

At the moment it seems that the snap releases are still in line, but snap cannot be used because of permission problems.

A solution is needed!

2

apt-mark hold docker-ce will hold docker-ce at the current version.

3

Ubuntu 18.04 is not supported at the moment, see https://github.com/rancher/rancher/issues/13888 for tracking support for it.

Until then use a supported OS and use package management of that OS to hold Docker versions, like one mentioned above.