Repo2docker cannot open in browser when using cached container


I work on mac with python 3.8.3 / jupyter-repo2docker 0.11.0.


jupyter-repo2docker -E .

works like a charm for me and I can open Jupyter lab in Firefox. Trying to first build the container and push it to dockerhub, then download and run locally does not work for me though.
I build the container using the Github action to
I would expect

docker run kkmann/unplanned-sample-size-adaptation

to give me non-editable version of the repo locally. The container seems to run fine and gives me the usual link rto open in my browser (e.g. but following that results in

Unable to connect

Firefox can't establish a connection to the server at

Do I need to specify more arguments for run? I could not find any documentation on this use case online.

Hi. By default docker run doesn’t forward any ports- this applies to all Docker images, not just those created by repo2docker. Try something like

docker run -p 8888:8888 kkmann/unplanned-sample-size-adaptation

to map port 8888 on localhost/ to port 8888 inside the container.

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