For registry.access.redhat.com/ubi8/ubi-minimal this image, i need ps utility to be installed. There is no yum package manager available in the image. Instead , we have microdnf.
microdnf install procps says there is no such package named procps
In the Dockerfile, add the following statement and you should be able to use ps
RUN microdnf update && microdnf install procps