Running docker container through python API with specific ulimit

Dear all, I don't know wether it is an issue or not, but I noticed a very strange behaviour when trying to set some limits whiler running a docker container.

I described the problem here:
https://stackoverflow.com/questions/54884874/running-docker-container-through-python-api-with-specific-ulimit

Here is a copy:

Now I want to create a container to run a dummy command inside an image following this simple documentation/tutorial: https://docker-py.readthedocs.io/en/stable/containers.html#container-objects

import docker
client = docker.from_env()
client.containers.run(shm_size='1g', ulimits=[docker.types.Ulimit(name='memlock', hard=-1), docker.types.Ulimit(name='stack', hard=67108864)], image='ubuntu:16.04', auto_remove=True,  command='date')

Here is the result:

--------------------------------------------------------------------------- ContainerError Traceback (most recent call last) in () ----> 1 client.containers.run(shm_size='1g', ulimits=[docker.types.Ulimit(name='memlock', hard=-1), docker.types.Ulimit(name='stack', hard=67108864)], image='ubuntu:16.04', auto_remove=True, command='date')

~/anaconda3/lib/python3.7/site-packages/docker/models/containers.py in run(self, image, command, stdout, stderr, remove, **kwargs) 812 if exit_status != 0: 813 raise ContainerError( --> 814 container, exit_status, command, image, out 815 ) 816

Although the following command works perfectly:

docker run --shm-size=1g --ulimit memlock=-1 --ulimit stack=67108864 --rm -t ubuntu:16.04 "date" What is the problem in the combination of options that I used ?

Thank you in advance for your help

Start with the documented containers.run example and the supplied docker.types.Ulimit configuration, then reproduce the ContainerError using ubuntu:16.04. Compare it with the equivalent docker run command and determine why the Python API combination fails; done means the discrepancy is explained and the affected behavior is corrected or documented.