Activate python virtualenv in Dockerfile

Question

I have a Dockerfile where I try to activate python virtualenv after what, it should install all dependencies within this env. However, everything still gets installed global

Answer 1

Although I agree with Marcus that this is not the way of doing with Docker, you can do what you want.

Using the RUN command of Docker directly will not give you the answer as it will not execute your instructions from within the virtual environment. Instead squeeze the instructions executed in a single line using /bin/bash. The following Dockerfile worked for me:

FROM python:2.7

RUN virtualenv virtual
RUN /bin/bash -c "source /virtual/bin/activate && pip install pyserial && deactivate"
...

This should install the pyserial module only on the virtual environment.