Description of problem:
UBI8 docker image (registry.access.redhat.com/ubi8/ubi-minimal:latest) cannot run any commands when ran on an s390x host.
Version-Release number of selected component (if applicable):
docker pull registry.access.redhat.com/ubi8/ubi-minimal:latest
100% reproducible on an s390x host.
Steps to Reproduce:
1. On a s390x host: docker pull registry.access.redhat.com/ubi8/ubi-minimal:latest
2. docker run -it registry.access.redhat.com/ubi8/ubi-minimal:latest cat /etc/hosts
Nothing, the container silently fails in the background.
etpgxek:~ # docker run -it registry.access.redhat.com/ubi8/ubi-minimal cat /etc/hosts
etpgxek:~ # docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
8222ce68495f registry.access.redhat.com/ubi8/ubi-minimal "cat /etc/hosts" 5 seconds ago Exited (132) 4 seconds ago zealous_poincare
The container prints out /etc/hosts. NOTE: ubi7 image works successfully.
# docker run -it registry.access.redhat.com/ubi7/ubi-minimal:latest cat /etc/hosts
::1 localhost ip6-localhost ip6-loopback
What is the underlying host os? I think that could be playing a role here. Have you tried this on a RHEL 8 host running on s390?
Product Manager - Red Hat Universal Base Image
etpgxek:~ # uname -a
Linux etpgxek 4.4.103-94.6-default #1 SMP Tue Jan 9 12:53:49 UTC 2018 (69ac2b4) s390x s390x s390x GNU/Linux
etpgxek:~ # cat /etc/os-release
PRETTY_NAME="SUSE Linux Enterprise Server 12 SP3"
I don't quite have the capability to change the host OS to RHEL - however, I'm under the impression that with Docker and the UBI8 that it shouldn't matter what the underlying host is?
The underlying host and machine type can certainly matter in a few cases. If the OS in the container requires features not present in the host kernel or if the OS in the container has been built with for a specific hardware generation then you can run into errors. RHEL 8, and therefor UBI8, was built for the z13 hardware platform on the s390x architecture. If your s390x instance isnt' a z13 or newer machine, the UBI 8 containers will not work.
It's unclear to me if there are software compatibility issues between SLES 12 SP3 and RHEL 8, but that might also be the case.
Nelson, can you provide more insight into the machine you're running this on?
Hey Josh - thanks for your follow-up! At the moment, I don't quite know what hardware platform this LPAR is running on top of, but let me reach out to others on my team to see if we can get more detailed specs for you.
Hey Josh - we got our system updated to z13 and the UBI8 docker image works as expected now. Thanks again for your help!
Thanks for the update and I'm glad it is working for you.