How are the opencloud users mapped to the users on the linux host, and run (or can?) the opencloud services using the corresponding userid (like sshd)

[J-u-n-o]

Running Truenas, and want to 'expose' each user folders and shared folders, like the samba mapping using a webinterface like opencloud.
From windows the user login and is assigned the corresponding linux user id to access the file, and the filesystem file attributes allow or prevent access.
Sshd is an simular example: a user logins and the connected ssh-client to the sshd-services for this user runs using the userid of this user.

A (dedicated/special) webservices can do something similar: When a (tcp) socket is connected, and after the user supplied its credentials the (user) service runs using the related userid and the service can (only) access what is allowed by the filesystem attributes.

Now for each user its files are accessible using the same filesystem attributes independent of the service used (ssh, samba, rsync, cloud-interface, ...).

How does Opencloud map its users to the users on the host system (runniung docker)?
Can Opencloud do this? Or is it a feature to be considered?
Or is Opencloud running a dedicated userid, which has access to all files (the related) user can/could access, and the usermanagement of Opencloud resticts access, so only the allowed files are seen using the opencloud (web) interface. But this could prevent the files to be accessable/seen for this connectec user using e.g. samba or ssh.

Possible scenarios:
When the userdatabase is fully in Opencloud they can share the userid, and have Opencloud do the file access determination.
Or use (partly) the host linux user database, run the services for the connected user using its userid, and have the host do the file access determination.

[BreezeDelegate]

OpenCloud doesn't switch to each logged-in user's Linux UID the way sshd does. It authenticates users through OIDC, while the storage process accesses files under its own service UID/GID. OpenCloud's users and spaces are logical identities, not a mapping to /etc/passwd accounts.

That distinction matters for your TrueNAS setup:

• Normal PosixFS mode: OpenCloud expects exclusive access to its storage tree. Its docs require the files to be accessible to the OpenCloud service user; changing that tree over Samba while OpenCloud runs isn't supported.
• PosixFS collaborative mode: external processes can change files and OpenCloud can pick up those changes (STORAGE_USERS_POSIX_WATCH_FS=true). There are still ownership and extended-attribute requirements, and it doesn't make OpenCloud impersonate each Samba user's Unix UID.

The PosixFS documentation covers both modes and their limitations.

So if the goal is merely to expose files through a web UI, collaborative mode may be worth testing. If you need identical Unix ACL enforcement for SSH, Samba and web access, OpenCloud isn't a drop-in replacement for a per-user POSIX session.