Transfer virtualenv to docker image

Question

Is it possible to transfer virtual environment data from a local host to a docker image via the ADD command?

Rather than doing pip installs inside the container, I would rather the user have all of that done locally and simply transfer the virtual environment into the container. Granted all of the files are the same name locally as in the docker container, along with all directories being nested properly.

This would save minutes to hours if it was possible to transfer virtual environment settings into a docker image. Maybe I am thinking about this in the wrong abstract.

It just feels very inefficient doing pip installs via a requirements.txt that was passed into the container, as opposed to doing it all locally, otherwise each time the image is started up it has to re-install the same dependencies that have not changed from each image's build.

Answer 1

We had run into this problem earlier and here are a few things we considered:

1. Consider building base images that have common packages installed. The app containers can then use the one of these base containers and install the differential.
2. Cache the Pip packages on a local path that can be mounted on the container. That'll save the time to download the packages.

Depending on the complexity of your project one may suit better than the other - you may also consider a hybrid approach to find maximum optimization.