diff --git a/Containerfile b/Containerfile index f512548..d01755b 100644 --- a/Containerfile +++ b/Containerfile @@ -1,27 +1,10 @@ -# This container build uses some special features of podman that allow -# a process executing as part of a container build to generate a new container -# image "from scratch". -# -# This container build uses nested containerization, so you must build with e.g. +# In order to make a base image as part of a Dockerfile, this container build uses +# nested containerization, so you must build with e.g. # podman build --security-opt=label=disable --cap-add=all --device /dev/fuse <...> -# -# # Why are we doing this? -# -# Today this base image build process uses rpm-ostree. There is a lot of things that -# rpm-ostree does when generating a container image...but important parts include: -# -# - auto-updating labels in the container metadata -# - Generating "chunked" content-addressed reproducible image layers (notice -# how there are ~60 layers in the generated image) -# -# The latter bit in particular is currently impossible to do from Containerfile. -# A future goal is adding some support for this in a way that can be honored by -# buildah (xref https://github.com/containers/podman/discussions/12605) -# -# # Why does this build process require additional privileges? -# -# Because it's generating a base image and uses containerization features itself. -# In the future some of this can be lifted. + +# NOTE: This container build will output a single giant layer. It is strongly recommended +# to run the "rechunker" on the output of this build, see +# https://coreos.github.io/rpm-ostree/experimental-build-chunked-oci/ FROM quay.io/fedora/fedora:rawhide as repos @@ -29,8 +12,6 @@ FROM quay.io/fedora/fedora:rawhide as repos FROM quay.io/fedora/fedora:rawhide as builder RUN dnf -y install rpm-ostree selinux-policy-targeted ARG MANIFEST=fedora-bootc.yaml -COPY --from=repos /etc/dnf/vars /etc/dnf/vars -COPY --from=repos /etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-* /etc/pki/rpm-gpg # The input git repository has .repo files committed to git rpm-ostree has historically # emphasized that. But here, we are fetching the repos from the container base image. # So copy the source, and delete the hardcoded ones in git, and use the container base @@ -38,17 +19,20 @@ COPY --from=repos /etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-* /etc/pki/rpm-gpg COPY . /src WORKDIR /src RUN rm -vf /src/*.repo -COPY --from=repos /etc/yum.repos.d/*.repo /src RUN --mount=type=cache,target=/workdir \ - --mount=type=bind,rw=true,src=.,dst=/buildcontext,bind-propagation=shared \ - --mount=type=bind,from=repos,src=/,dst=/repos \ - rpm-ostree compose image --image-config fedora-bootc-config.json \ - --cachedir=/workdir --format=ociarchive --initialize ${MANIFEST} \ - --source-root=/repos /buildcontext/out.ociarchive + --mount=type=bind,rw,from=repos,src=/,dst=/repos \ + rpm-ostree experimental compose rootfs --cachedir=/workdir --source-root-rw=/repos ${MANIFEST} /target-rootfs -FROM oci-archive:./out.ociarchive -# Need to reference builder here to force ordering. But since we have to run -# something anyway, we might as well cleanup after ourselves. -RUN --mount=type=bind,from=builder,src=.,target=/var/tmp \ - --mount=type=bind,rw=true,src=.,dst=/buildcontext,bind-propagation=shared \ - rm /buildcontext/out.ociarchive +# This pulls in the rootfs generated in the previous step +FROM scratch +COPY --from=builder /target-rootfs/ / +LABEL containers.bootc 1 +# This is an ad-hoc way for us to reference bootc-image-builder in +# a way that in theory client tooling can inspect and find. Today +# it isn't widely used. +LABEL bootc.diskimage-builder quay.io/centos-bootc/bootc-image-builder +# https://pagure.io/fedora-kiwi-descriptions/pull-request/52 +ENV container=oci +# Make systemd the default +STOPSIGNAL SIGRTMIN+3 +CMD ["/sbin/init"]