dockerfile: add minimal image with provisioners support

Signed-off-by: Mikhail Ushanov <gm.mephisto@gmail.com>

Dockerfile

@@ -0,0 +1,30 @@
+FROM ubuntu:16.04
+
+ENV DEBIAN_FRONTEND noninteractive
+
+RUN apt-get update && apt-get install -y \
+    locales \
+    openssh-server \
+    sudo
+
+RUN locale-gen en_US.UTF-8
+
+RUN if ! getent passwd vagrant; then useradd -d /home/vagrant -m -s /bin/bash vagrant; fi \
+    && echo 'vagrant ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers \
+    && mkdir -p /etc/sudoers.d \
+    && echo 'vagrant ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers.d/vagrant \
+    && chmod 0440 /etc/sudoers.d/vagrant
+
+RUN mkdir -p /home/vagrant/.ssh \
+    && chmod 0700 /home/vagrant/.ssh \
+    && wget --no-check-certificate \
+      https://raw.github.com/hashicorp/vagrant/master/keys/vagrant.pub \
+      -O /home/vagrant/.ssh/authorized_keys \
+    && chmod 0600 /home/vagrant/.ssh/authorized_keys \
+    && chown -R vagrant /home/vagrant/.ssh
+
+RUN mkdir -p /run/sshd
+
+CMD /usr/sbin/sshd -D \
+    -o UseDNS=no \
+    -o PidFile=/tmp/sshd.pid