Mirantis Container Runtime
Added support for
cgroupsv2 which limits process resource usage (such as CPU, memory, and disk). MCR uses
cgroupsin conjunction with Linux namespaces to isolate processes inside containers. As a result, rootless is now a fully supported feature.
Added support for using docker logs to read container logs, regardless of the configured logging driver or plugin. Previously, docker logs did not support the use of many third party logging drivers, and this led to log data gathering issues.
Refer to the Docker documentation, Configure logging drivers.
Added support for Ubuntu 20.04.
Added several CLI improvements. Along with the removal of some older and mostly unused commands, various new commands and flags have been added that make it easier to get started and to script using MCR:
docker pushhas been modified to align the default behavior with
docker pull. Pushing an image name without a tag now pushes only the
:latestrather than all tags, and
-a/all-tagscan now be used to push all the tags of an image.
--pullflag has been added to the
docker createcommands, affording greater control over when users pull images. The option is tristate, offering
-env-fileflag has been added to
docker exec, allowing use with a file that contains environment variables and subsequent printing or use of any of the variables inside the file.
For a complete list of the CLI improvements, refer to the Docker release notes.
docker pullrequests against non-compliant registries that do not support pull-by-digest now results in a warning and deprecation notice (docker/cli#2872).
Unauthenticated TCP access now results in a more severe warning and deprecation notice (moby/moby#41285).
aufsstorage driver is deprecated (docker/cli#1484).
The legacy Dockerfile
ENV name valuesyntax is deprecated. Use
ENV name=valueinstead (docker/cli#2743).
The previously deprecated
filterparameter has been removed for API v1.41 and up (moby/moby#40491).
The distribution manifest v2 schema 1 is now disabled on push (moby/moby#41295).
MalformedHostHeaderOverridehack has been removed, causing CLI v1.12 and earlier to break. Affected users should upgrade to a more recent client version or set the
DOCKER_API_VERSIONenvironment variable to the needed API version (moby/moby#39076).
docker enginesubcommands have been removed (docker/cli#2207).
docker deploycommand and
.dab(“Docker Application Bundle”) file format have both been removed in favor of using
docker stack deploywith
docker search --automatedand
docker search --starsflags have been removed in favor of using their
docker search --filterequivalents (docker/cli#2338).
Use of reserved namespaces in engine labels is deprecated (docker/cli#2326).