-# Install dependencies and set up system.
-RUN /usr/bin/apt-get update && /usr/bin/apt-get install -q -y python2.7-dev python3 python-setuptools python3-setuptools libcurl4-gnutls-dev curl git procps libattr1-dev libfuse-dev libgnutls28-dev libpq-dev python-pip
+RUN perl -ni~ -e 'print unless /jessie-updates/' /etc/apt/sources.list
+
+ENV DEBIAN_FRONTEND noninteractive
+
+# Install dependencies.
+RUN /usr/bin/apt-get update && /usr/bin/apt-get install -q -y python2.7-dev python3 python-setuptools python3-setuptools python3-pip libcurl4-gnutls-dev curl git procps libattr1-dev libfuse-dev libgnutls28-dev libpq-dev python-pip unzip python3-venv python3-dev
+
+# Install virtualenv
+RUN /usr/bin/pip install virtualenv