Yum and rockylinux:[8|9]-minimal base

[lgorenstein]

It appears that base images rockylinux:[8|9]-minimal do not contain yum or dnf executable (only the rpm one). Which brings havoc when using building blocks that depend on having yum (e.g. the mkl() one).

Clearly not including yum/dnf was an intentional choice Rocky made for the -minimal container. In itself, this is is not a big problem in HPCCM context (there's always a slightly larger yum-containing regular rockylinux:[8|9] base image instead). But this could bite someone trying to do a multistage build using -minimal for the runtime stage (similar to the multistage example with Nvidia's -devel and -base). Perhaps HPCCM could add internal logic to install yum if yum is not in the image?

---

The two-stage MKL recipe that crashed on the second stage and led me to discovery:

Stage0 += baseimage(image='rockylinux:9', _as='devel')
Stage0 += mkl(eula=True, version='2020.0-088')

Stage1 += baseimage(image='rockylinux:9-minimal')
Stage1 += Stage0.runtime(_from='devel')

Or the smallest reproducible example.py with a single stage:

Stage0 += baseimage(image='rockylinux:9-minimal')
Stage0 += mkl(eula=True, version='2020.0-088')

Generated Singularity definition file:

$ hpccm --version
25.3.0

$ hpccm --recipe example.py --format singularity --singularity-version 3.8
BootStrap: docker
From: rockylinux:9-minimal
%post
    . /.singularity.d/env/10-docker*.sh

# MKL version 2020.0-088
%post
    rpm --import https://yum.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
    yum install -y dnf-utils
   ^^^^^^^^^^^^^^^^^^^^^^^^^^
[...]

Which then bombs out when building the container:

$ singularity build example.sif example.def
[,,,.]
INFO:    Running post scriptlet
+ . /.singularity.d/env/10-docker2singularity.sh
++ export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
++ PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+ rpm --import https://yum.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+ yum install -y dnf-utils
/.post.script: line 5: yum: command not found
FATAL:   While performing build: while running engine: while running %post section: exit status 127

[samcmill]

It looks like you are supposed to use microdnf with the Rocky minimal images.

I think the approach should probably be something like

1. Detect that an image is a "minimal" one and set a new global config variable
2. If the "minimal" config is true, then the packages building block should use microdnf rather than yum.
3. Create a new microdnf building to handle the new packages case? Or extend the existing yum building block?

In the meantime, the Rocky minimal images are not supported.

[lgorenstein]

The more standalone building blocks, the greater the temptation to use them (outside of packages(), that is). In this sense, I am not sure if microdnf deserves its own building block (given that dnf itself does not have one).

[lgorenstein]

An ugly hack in the interim:

Stage0 += baseimage(image='rockylinux:9', _as='devel')
Stage0 += mkl(eula=True, version='2020.0-088')

Stage1 += baseimage(image='rockylinux:9-minimal')
Stage1 += shell(commands=['alias yum=microdnf'])      # There is no spoon!
Stage1 += Stage0.runtime(_from='devel')