docker-images/README.adoc

= Docker images

My amateurish attempts at creating docker images.

== tastytea/gentoo-base

A minimal Gentoo image without build dependencies. I use it as a base for other
images, so that I don't have to compile everything from scratch all the time.

=== Features

* Replaced `-O2` with `-Os` in `${COMMON_FLAGS}`.
* Turned off sandboxing (https://bugs.gentoo.org/680456[Bug 680456]).
* Turned off documentation installation.
* `MAKEOPTS="-j1"`.
* Deactivated some use-flags, added `minimal`.
* Packages installed: `sys-apps/portage` + run-time dependencies.
* Deleted: Documentation, translations, time zone info.

=== Example Dockerfile

[source,docker]
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# Portage tree.
FROM gentoo/portage:latest as portage

# Minimal Gentoo image without build dependencies.
FROM tastytea/gentoo-base:latest as gentoo-base

# Build packages in /workdir.
FROM gentoo/stage3-amd64:latest as build
COPY --from=portage /var/db/repos/gentoo /var/db/repos/gentoo
COPY --from=gentoo-base / /workdir
RUN cp /workdir/etc/portage/make.conf /etc/portage/make.conf
RUN eselect profile set default/linux/amd64/17.1
RUN mkdir -p /etc/portage/package.accept_keywords
RUN echo 'games-misc/cowsay' >> \
    /etc/portage/package.accept_keywords/cowsay
RUN emerge --root=/workdir --buildpkg=y --usepkg --quiet games-misc/cowsay

# Final image.
FROM scratch
COPY --from=build /workdir /
ENV LANG "en_DK.utf8"
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