Rootless Podman
User Mapping
Podman maps users inside of the container to unprivileged users on the host system by using subordinate ID ranges
/etc/subuid
/etc/subgid
To generate the subordinate ID ranges, use the usermod command:
sudo usermod --add-subuids 100000-165535 \
--add-subgids 100000-165535 student
# The /etc/subuid and /etc/subgid files must exist before you define the subordinate ID ranges
# for the new subordinate ID ranges to take effect:
podman system migrate
To verify the mapped user
podman run -it registry.access.redhat.com/ubi9/ubi id
podman top e6116477c5c9 huser user
When you execute a container with elevated privileges on the host machine, the root mapping does not take place even when you define subordinate ID ranges