Containerfile

# This replaces the (throughput) kernel with kernel-rt for latency-sensitive workloads.
FROM quay.io/okd/centos-stream-coreos-9:4.12-x86_64
# First, at the current time for replacing the kernel this invocation is required.
# This need will be lifted in the future.
RUN rpm-ostree cliwrap install-to-root /
# Note a few things here.
#  - The image does not have RT and NFV repositories enabled.  Right now rpm-ostree
#    doesn't expose `dnf config-manager`, so we manually enable the yum repos with sed.
#  - The default image has the meta-package "kernel" installed for the throughput kernel,
#    but we don't install `kernel-rt` because that has dependencies on a lot of other
#    things.
#  - We need to do the swap as a single "transaction" to avoid broken dependencies.
RUN sed -i "/\[rt\]/,/\[/  s/enabled=0/enabled=1/" /etc/yum.repos.d/centos-addons.repo && \
    sed -i "/\[nfv\]/,/\[/  s/enabled=0/enabled=1/" /etc/yum.repos.d/centos-addons.repo && \
    rpm-ostree override remove kernel kernel-{core,modules,modules-extra} \
      --install kernel-rt-core --install kernel-rt-modules \
      --install kernel-rt-modules-extra --install kernel-rt-kvm && \
    ostree container commit