I have a container (running image quay.io/keycloak/keycloak:21.1.1) where cat /etc/os-release reports the following (excerpt):

NAME="Red Hat Enterprise Linux"
VERSION="9.1 (Plow)"

openssl is not installed, neither is yum. (yum install openssl fails with "command not found".) So how can I install OpenSSL into such an image (perhaps it is a UBI micro-image)?

1 Answer 1


The Keycloak image quay.io/keycloak/keycloak:21.1.1 is currently based on the Red Hat Universal Base Image ubi9-micro, which lacks any package manager (dnf, rpm, yum) in order to minimize size.

I came across a couple of tricks for installing packages regardless, e.g. one involving buildah mount and another one involving multi-stage build plus yum install --installroot /mnt/rootfs. The second now serves well in my scenario.

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