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dockerrheldocker-image

microdnf shows librhsm-WARNING Found 0 entitlement certificates

Problem

I am trying to install nmap-ncat package into a container created with this image by microdnf pkg-manager. I run

microdnf update
microdnf -y install nmap-ncat

Both cmds output

(microdnf:xxx): librhsm-WARNING **: 12:00:00.000: Found 0 entitlement certificates

...

but both cmds seem to be working properly after this. I can actually see ncat cmd's help by --help option so it seems the install is complete. I googled about this issue and found this. It seems since I am not a red hat subscriber, Red Hat Enterprise Linux(RHEL) which is the OS used by the image limits what I can do. Maybe the base image of the image is one of red hat universal base images (ubi) by which

allow commercial and open source developers to build containers based on RHEL without requiring them or their users to be RHEL subscribers

(source) because the output of microdnf -y install nmap-ncat is like

Installing: ... ;ubi-8-baseos
Installing: ... ;ubi-8-appstream

and this shows both ubi-8-baseos and ubi-8-appstream are RHEL 8 UBI repositories (but I am not really sure about this). My questions are

  1. Why did the warning come up while I successfully installed nmap-ncat?
  2. Am I entitled to use nmap-ncat with this image?
Solution

  • You can ignore the warning: just like running regular dnf, microdnf is configured to work with Red Hat subscriptions. If you have entitlements on your host, they will be automatically mounted into the container, giving you access to subscription-only resources.

    If you don't have entitlements, you'll see the warning, but you can ignore it.

    Am I entitled to use nmap-ncat with this image?

    You will not be able to install software to which you do not have an entitlement, so if you can install it, you're fine.