hadolint fixes/best practices added Enable -o pipefail for RUN commands with pipes so any errors in the pipeline cause a failure. use wget -q to reduce log size for large file downloads. Run all apk with --no-cache so I don't need to remove /var/cache/apk/*. Quote variables in RUN shell scripts unless they need to be expanded. Don't use direct variable substitution in printf. Update comment for installing python packages using apk. Remove --use-feature=in-tree-build from local_pip pip command. This feature is the default with newer pips and is now an error if used.

Babel
Jinja2
MarkupSafe
Pygments
alabaster
certifi
charset-normalizer
docutils
idna
imagesize
packaging
pyparsing
requests
six
snowballstemmer
sphinxcontrib-serializinghtml
sphinxcontrib-websupport
urllib3