I did actually recreated the issue by using your Dockerfile. I created a one manager and worker in play with docker online. play with docker is provided by docker itself. this is a alpine linux. i tried to run your Docker file inside the linux alpine command line as commands and it is stuck after downloading external data on building cxx object sitkN4BiasFieldCorrectionImageFilter.cxx.o again just like when i tried to build image from docker file. There is something happening during downloading and building which may cause hanging on internet and i think somehow this is
related to simpleITK web site.
I also running another Dockerfile in another manager node inside play with docker, yet it is not finished yet. this one i build a docker imager out of provide Dockerfile by you. I will inform you about the results.
sag