anchor.diff:  # Install pxelinux.0
   RUN mkdir app/tftp && cp /usr/lib/syslinux/pxelinux.0 /app/tftp
   
  +# Import CoreOS Signing Key
  +RUN wget -qO- https://coreos.com/security/image-signing-key/CoreOS_Image_Signing_Key.pem | gpg --import
  +
   # Install coreos pxe images
   RUN cd /app/tftp && \
  -    wget -q http://stable.release.core-os.net/amd64-usr/current/coreos_production_pxe.vmlinuz
  +    wget -q http://stable.release.core-os.net/amd64-usr/current/coreos_production_pxe.vmlinuz && \
  +    wget -q http://stable.release.core-os.net/amd64-usr/current/coreos_production_pxe.vmlinuz.sig && \
  +    gpg --verify coreos_production_pxe.vmlinuz.sig
   
   # Download image to /tmp
   RUN cd /tmp && \
  -    wget -q http://stable.release.core-os.net/amd64-usr/current/coreos_production_pxe_image.cpio.gz
  +    wget -q http://stable.release.core-os.net/amd64-usr/current/coreos_production_pxe_image.cpio.gz && \
  +    wget -q http://stable.release.core-os.net/amd64-usr/current/coreos_production_pxe_image.cpio.gz.sig && \
  +    gpg --verify coreos_production_pxe_image.cpio.gz.sig
   
   # Extract and combine with /oem
   RUN mkdir /tmp/initrd && \
       cd /tmp/initrd && \
       cat /tmp/coreos_production_pxe_image.cpio.gz | gzip -d | cpio -i && \
  -    cp -R /oem/* . && \
  +    unsquashfs -f -d ./tttmp usr.squashfs && \
  +    cp -R /oem/* ./tttmp && \
  +    rm usr.squashfs && \
  +    mksquashfs ./tttmp ./usr.squashfs && \
  +    rm -R tttmp && \
       find | cpio -o --format=newc | gzip -9c > /app/tftp/coreos_production_pxe_image_oem.cpio.gz
   
   # Cleanup
  
positive.code: echo "deb http://vesta.informatik.rwth-aachen.de/ftp/pub/Linux/ubuntu/ubuntu/ trusty-backports main restricted universe multiverse" >> /etc/apt/sources.list
  
  # Install deps
  RUN apt-get update && apt-get install -y dnsmasq syslinux wget openssh-server openssh-client php5-cli
  
  COPY app /app
  COPY oem /oem
  
negative.code: #     gpg --verify coreos_production_pxe_image.cpio.gz.sig
  
  
  # Customizations
  ENV INTERFACE=eth1
  
  