charm not setting docker-opts in /etc/default/docker

[Jeff Hillman]

k8s 1.19
latest/stable docker charm
openstack ussuri on focal

When running `juju config docker docker-opts="--default-ulimit=memlock=-1:-1" nothing gets set in /etc/default docker. The file just stays as it was.

[George Kraft (cynerva)]

Thanks for the report. The docker-opts config option clearly is not implemented in the charm:

$ git grep docker-opts
config.yaml: docker-opts:
reactive/docker.py:@when('config.changed.docker-opts', 'docker.ready')
reactive/docker.py: Options here will be merged with configured docker-opts when layer-docker

The charm responds to config.changed.docker-opts, and docker-opts is mentioned in a docstring, but there is no actual reference to docker-opts in the code.

[Jeff Hillman (jhillman)]

subscribed field high

[Jeff Hillman (jhillman)]

FYI, the workaround of

juju run -m <model> --application docker -- 'echo DOCKER_OPTS=\"--default-ulimit=memlock=-1:-1\" > /etc/default/docker ; service docker restart'

Is not persistent. Because /etc/default/docker is coming from the docker.defaults template file, /etc/default/docker is being intermittently overwritten.

[George Kraft (cynerva)]

PR: https://github.com/charmed-kubernetes/charm-docker/pull/19

[George Kraft (cynerva)]

Cherry-pick to stable branch: https://github.com/charmed-kubernetes/charm-docker/commit/eac32dd6ebd999ebd0b893f7d20740593d3e7989