PureVPN Login will fail without this

[JtMotoX]

When the container is coming up, it will fail during login with the following:

spawn purevpn --login
  Username: ***
  Password: 

Verifying your credentials ...Traceback (most recent call last):
  File "purevpn.py", line 1363, in <module>
  File "purevpn.py", line 423, in login
  File "UserDict.py", line 40, in __getitem__
KeyError: 'USER'
[28] Failed to execute script purevpn

To fix this, you need to add the following before the spawn command:
export USER="$(whoami)"

EDIT

Or even better would be to add this to the Dockerfile:

RUN echo 'export USER="$(whoami)"' >>/etc/profile
RUN echo ". /etc/profile" >>~/.bashrc

And add this to the top of the entrypoint:
. /etc/profile

This will make sure that the entrypoint script will contain this variable, as well as if you do a 'docker exec ... bash'