Alternative to autofs to mount CIFS folders in user home folders in multi-user environment

Question

My use case seems very simple. I want to automount CIFS folder CIFS1 and CIFS2 which exist for all users on my fileserver in each user home during login on this multi-user 18.04 Ubuntu machine.

So if user1 login, i mount :

• /home/user1/CIFS1
• /home/user1/CIFS2.

If user2 login, i mount :

• /home/user2/CIFS1
• /home/user2/CIFS2.

I have an already a working mounting command to do this, using Kerberos ticket / SSSD to authenticate :

sudo mount -v -t cifs -o user=${USER},cruid=${USER},sec=krb5,uid=${UID} //isilon.mydataserver/CIFS1/${USER} /home/${USER}/CIFS1

sudo mount -v -t cifs -o user=${USER},cruid=${USER},sec=krb5,uid=${UID} //isilon.mydataserver/CIFS2/${USER} /home/${USER}/CIFS2

Works well, but now i want to automount these folders directly after login, with correct ${USER} information injected into autofs configuration.

And ... it seems impossible, i try many things, direct or indirect mapping, executable automap, without success.

The [mountpoint] [option] [location] pattern of autoconf files accept injection of environnement variable (USERS, UID, etc.) only in the option/location part.

In sudo nano /etc/auto.master i have :

/- /etc/auto.cifs --ghost

Following the sun autofs pattern for direct mounting : [mountpoint] [option] [location], my /etc/auto.cifs config contain :

/home/${USER}/CIFS1 -fstype=cifs,user=${USER},cruid=${UID},sec=krb5,uid=${UID} ://isilon.mydataserver/CIFS1/${USER}

/home/${USER}/CIFS2  -fstype=cifs,user=${USER},cruid=${UID},sec=krb5,uid=${UID} ://isilon.mydataserver/CIFS2/${USER}

Reloading configuration :

sudo systemctl reload autofs

During users login, this configuration create litteraly a /home/${USER}/CIFS1 folder and not an /home/user1/CIFS1 or /home/user2/CIFS1 folder ...

Is there a way to obtain this behavior (mounting CIFS folder into multi-users environment : /home/$USER with $USER = user1, user2, ...) using autofs, or another method compatible with Kerberos / SSSD / CIFS authentification ?

Edit1 : I precise to readers that i cannot modify the Active Directory schema in place to use the automounting function of SSSD/AutoFS :(

Edit2 : I also try to run bash program from auto.master with program:/etc/auto.cifs , but it seems that doesn't answer to this problem because program could only return the [option][location] and not the [mountpoint] part.

Answer 1

@reyman64 - did you find a solution to your issue? I'm currently in the same situation you described above and have been scouring the interwebs but haven't found a solution. If I can figure out how to set the user variable as part of the mount point it would be golden.

Based on the detailed response here, the user variable in the key position is set to the user that runs the autofs daemon which is always root. Looks like the only possible solution is to have auto.master execute a script.