This document describes the latest changes, enhancements, known issues, and fixes for Mirantis Container Runtime (MCR) for versions 19.03.x.
Upgrading to the product combination [MKE 3.3.x + MCR 19.03.x + SLES 15 SP3/RHEL 8] can fail due to nodes that are not ready and MKE system containers that do not start. To resolve this problem, refer to Avoid firewall conflicts.
In developing MCR 19.03.x, Mirantis has been transitioning from legacy Docker Hub-issued licenses to JWT licenses, as detailed below:
Versions 19.03.0 to 19.03.10: Docker Hub licenses only
Versions 19.03.11 to 19.03.17: Docker Hub licenses and JWT licenses
Versions 19.03.18 and later: JWT licenses only
Using a JWT license with an MKE instance that manages MCR causes the engine to log error messages, though MCR does not fail. This applies to MKE 3.4.x versions prior to 3.4.6 and MKE 3.3.x versions prior to 3.3.13.