Cache Downloaded PIP Packages in Dockerfile

My Dockerfile below has RUN pip install commands on each line. This is done so that each time I run my docker build command it doesn’t take forever to build.

FROM ubuntu
MAINTAINER Mike Chirico <>
RUN apt-get update
RUN apt-get install -y python sqlite3 vim
RUN apt-get install -y python-setuptools python-dev build-essential python-pip

# Yes, do this twice so it get's cached
RUN pip install --upgrade pip
RUN pip install gunicorn==19.6.0
RUN pip install numpy==1.11.1
RUN pip install pandas==0.18.1

RUN mkdir /src
ADD requirements.txt /src
ADD _loadFacebook.sql /src
ADD /src
ADD /src
ADD /src
ADD /src

# Someday we'll forget to update the above, so
# I actually repeat the software listing in the
# requirements.txt. Plus, add anything that you
# don't want cached. It will not pull pandas again.
RUN pip install -r /src/requirements.txt

Now, let’s suppose I want to build mchirico/facebook-group-scrape:latest. The first time I run this, it’s going to upgrade pip, gunicorn, numpy and then take forever pulling down pandas. Obviously, after you pull down pandas, you want to pip to store this in the cache. In order to cache the results of pip, you have to put each one on a separate line.

docker build -t mchirico/facebook-group-scrape:latest .