Proposal: Disable apt caching

[joshuataylor]

When running apt-get install foo, the result is cached and requires an apt-get clean to remove this cache.
However, adding

RUN echo "Acquire::http {No-Cache=True;};" > /etc/apt/apt.conf.d/no-cache

As an initial step will mean that packages are not cached with apt, and will not require an apt-get clean.

Thoughts?

[nickschuch]

ah! one liner at the beginning = less lines later on? Im keen!