Public Key error installing kubctl using oraclelinux:8-slim as a basic image

[gong4soft]

Using kubernetes.repo as follows: [kubernetes] name=Kubernetes baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64 enabled=1 gpgcheck=1 repo_gpgcheck=1 gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg

Then run "microdnf install -y kubectl", I got an error "failed to parse public key for /var/cache/yum/metadata/kubernetes-8-x86_64/yum-key.gpg"

Any idea how to fix this problem? Thanks in advance, Yi