anchor.diff:  RUN curl -L https://github.com/docker/machine/releases/download/v0.6.0/docker-machine-`uname -s`-`uname -m` > /usr/local/bin/docker-machine \
     && chmod +x /usr/local/bin/docker-machine
   
  +# install gcloud sdk
  +RUN wget https://dl.google.com/dl/cloudsdk/channels/rapid/downloads/google-cloud-sdk-${GOOGLE_CLOUD_SDK_VERSION}-linux-x86_64.tar.gz \
  +  && tar xzf google-cloud-sdk-${GOOGLE_CLOUD_SDK_VERSION}-linux-x86_64.tar.gz \
  +  && rm google-cloud-sdk-${GOOGLE_CLOUD_SDK_VERSION}-linux-x86_64.tar.gz \
  +  && google-cloud-sdk/install.sh --usage-reporting=false --path-update true --bash-completion true --rc-path ~/.bashrc \
  +  && pip install crcmod==1.7
  +
   # preload host keys for github.com
   RUN ssh-keyscan -H github.com >> ~/.ssh/known_hosts
  
positive.code:   aruba:0.6.2 \
    cucumber:2.0.2
  
  
  # install terraform and custom providers
  RUN wget https://releases.hashicorp.com/terraform/${TERRAFORM_VERSION}/terraform_${TERRAFORM_VERSION}_linux_amd64.zip \
    && wget https://github.com/Samsung-AG/terraform-provider-execute/releases/download/${TERRAFORM_EXECUTE_VERSION}/terraform-provider-execute_linux_amd64.tar.gz \
  
negative.code: # versions
  # TODO: install from source instead?
  ENV GOLANG_DEB_VERSION 2:1.5.1-4~bpo8+1
  ENV GOOGLE_CLOUD_SDK_VERSION 106.0.0
  ENV KUBERNETES_VERSION v1.2.0
  ENV TERRAFORM_VERSION 0.6.14
  ENV TERRAFORM_EXECUTE_VERSION v0.0.2
  