Are container ID's guaranteed to be unique across users in rootless podman?

[cjvolzka]

The title sums it up. Are container ID's guaranteed to be unique across users in rootless podman?

According to the OCI Runtime spec

id (string, REQUIRED) is the container's ID. This MUST be unique across all containers on this host. There is no requirement that it be unique across hosts.

Since I don't believe there's a central way to list all containers across users in rootless podman, I want to to confirm if running container IDs are still guaranteed to always be unique when running rootless podman.

[rhatdan]

I don't believe so, and I don't think it matters as long as they are unique for each user session. Container IDs are per instance of the podman database.

[Luap99]

Right there is guarantee as podman can only check its own/db storage so other user cannot be checked.

However I want to highlight that ids are created from random 32 bytes encoded as 64 char hex string. So we have 2^256 ids. Getting a conflict there is close to impossible (assuming a proper random generator)