CentOS base images have a layer with unnecessary /var/yum/cache

[Mark Goddard]

Since https://review.opendev.org/#/c/682600/, the following lines result in /var/yum/cache being present in one of the layers of the base image:

RUN {{ macros.install_packages(base_centos_yum_repo_packages | customizable("centos_yum_repo_packages"), chain=True, clean=False) }} \
{% for repo in base_centos_yum_repos_to_disable | customizable('centos_yum_repos_to_disable') -%}
    && yum-config-manager --disable {{ repo }} \
{% endfor -%}
{% for key in base_centos_yum_repo_keys | customizable('centos_yum_repo_keys') -%}
    && rpm --import {{ key }} \
{% endfor -%}
    && /bin/true

{% block base_centos_repo_overrides_post_yum %}{% endblock %}

RUN {{ macros.rpm_security_update(clean_package_cache) }}

This is because is it not cleaned in the first RUN statement. This adds 76MB to the image. Also, using two separate RUNs which results in an extra 23MB due to updates to /var/lib/rpm/Packages.

Found via https://github.com/wagoodman/dive.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/691512

[Radosław Piliszek (yoctozepto)]

Ah, yeah. Missed the layering aspect. Good catch.

We should really think about the build-from-outside approach in the long run.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/691512
Committed: https://git.openstack.org/cgit/openstack/kolla/commit/?id=fe00a87ec8e6257ad1724b342b70811c03117b58
Submitter: Zuul
Branch: master

commit fe00a87ec8e6257ad1724b342b70811c03117b58
Author: Mark Goddard <email address hidden>
Date: Sun Oct 27 11:43:01 2019 +0000

    Remove /var/yum/cache from CentOS base image

    Since https://review.opendev.org/#/c/682600/, the following lines result
    in /var/yum/cache being present in one of the layers of the base image:

    RUN {{ macros.install_packages(base_centos_yum_repo_packages |
            customizable("centos_yum_repo_packages"), chain=True,
            clean=False) }} \
    {% for repo in base_centos_yum_repos_to_disable |
        customizable('centos_yum_repos_to_disable') -%}
            && yum-config-manager --disable {{ repo }} \
    {% endfor -%}
    {% for key in base_centos_yum_repo_keys |
        customizable('centos_yum_repo_keys') -%}
            && rpm --import {{ key }} \
    {% endfor -%}
        && /bin/true

    {% block base_centos_repo_overrides_post_yum %}{% endblock %}

    RUN {{ macros.rpm_security_update(clean_package_cache) }}

    This is because it is not cleaned in the first RUN statement. This adds
    76MB to the image. Also, using two separate RUNs which results in an
    extra 23MB due to updates to /var/lib/rpm/Packages.

    Found via https://github.com/wagoodman/dive.

    Change-Id: I0302ee1dfc10a2b7df127ac6a7764a84b1d74a33
    Closes-Bug: #1850036

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/kolla 9.0.0.0rc1 release candidate.