anchor.diff:  COPY --from=docs/docker.github.io:v17.03 ${TARGET} ${TARGET}
   COPY --from=docs/docker.github.io:v17.06 ${TARGET} ${TARGET}
   
  -# The archives are self-browseable and each come with an index.html. This creates
  -# a conflict with the index.html and 404.html from the master build. The easiest
  -# solution is to just overwrite them again here.
  -COPY --from=builder ${TARGET}/index.html ${TARGET}/index.html
  -COPY --from=builder ${TARGET}/404.html ${TARGET}/404.html
  +# Get the built docs output from the previous build stage
  +# This ordering means all previous layers can come from cache unless an archive
  +# changes
   
  -# Get the nginx config from the nginx-onbuild image
  -COPY --from=docs/docker.github.io:nginx-onbuild /etc/nginx/conf.d/default.conf /etc/nginx/conf.d/default.conf
  +COPY --from=builder ${TARGET} ${TARGET}
   
   # Serve the site (target), which is now all static HTML
   CMD echo -e "Docker docs are viewable at:\nhttp://0.0.0.0:4000"; exec nginx -g 'daemon off;'
positive.code: RUN find ${TARGET} -type f -name '*.html' | grep -vE "v[0-9]+\." | while read i; do sed -i 's#href="https://docs.docker.com/#href="/#g' "$i"; done
  
  # BUILD OF MASTER DOCS IS NOW DONE!
  # Reset to alpine so we don't get any docs source or extra apps
  FROM nginx:alpine
  
  # Set the target again
  ENV TARGET=/usr/share/nginx/html
  
  # Get the built docs output from the previous step
  COPY --from=builder ${TARGET} ${TARGET}
  
  # Get all the archive static HTML and put it into place
  # To add a new archive, add it here
  # AND ALSO edit _data/docsarchives/archives.yaml to add it to the drop-down
  COPY --from=docs/docker.github.io:v1.4 ${TARGET} ${TARGET}
  
negative.code: # Here is the sequence:
  # 1.  Set up the build
  # 2.  Fetch upstream resources
  # 3.  Build static HTML from master
  # 4.  Reset to clean tiny nginx image
  # 5.  Copy Nginx config and archive HTML, which don't change often and can be cached
  # 6.  Copy static HTML from previous build stage (step 3)
  #
  # When the image is run, it starts Nginx and serves the docs at port 4000
  
  