Experimental Physics and
Industrial Control System

Oscar Ibañez via Tech-talk <tech-talk at aps.anl.gov> · Wed, 21 Apr 2021 22:40:00 +0200

Hi Kay,

I have re-read my message and I think that I know why we are not

understanding each other.

When I say "low-privileged account" (or a high one), I don't mean an OS

user account. What I mean is a different worker profile using Phoebus.

Maybe an example could help:

Imagine that you have a computer account named "john". John is an

account with some privileges. It does not matter which ones. Using that

account, a scientist is running Phoebus. As a scientist, he may view and

change a few things. Not many. However, when that scientists finishes

his task, he gets up and he leaves its seat available for an engineer.

The enginner can view and modify the same PVs that the scientist,

however, he also may view and change other things. So, he changes his

current Phoebus profile from scientist to engineer. His screen changes

and now he is capable of changing many things.

Take into account that the computer session has not changed. No "sudos".

No command line. The computer account is still the same, "john". Nothing

has changed. The different worker profiles exist inside Phoebus.

Best,

Óscar

El 21/04/2021 a las 21:49, Kasemir, Kay escribió:

We are going to have several users using Phoebus. Different users have
different permissions to view and to edit, like any other system.
...
the change has to be made without logging out from the current computer session.

Permissions to do _what_?
Write PVs?
That's handled by Channel Access (or PV Access) security, which is based on the current user.
Phoebus (or EDM, MEDM, python CA library, command line caput, ...) don't have any way to change that user.
The only option you have is either log out & log back in,
or use 'sudo' to change user and start another instance of the program as that different user.

-Kay

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System