All,
A few further comments about permissions:
Imagine Toaster as a host for a build farm. Users log in through Toaster,
configure and
launch builds, view and download their results. Now imagine what Toaster has to
do to make
this happen: User A logs in, configures and launches a build. Toaster has to
create a directory
for that build and start the build process in that directory. Simultaneously,
user B does the same
thing. Toaster has to be able to create N directories for N simultaneous users
and be able to
write into these directories and maintain them all separately. To complicate
matters, user A
could start a second and a third build. Toaster will have to keep track of
these builds on behalf of
each user. In this scenario Toaster is the owner of these directories, not the
individual users.
In this scenario, users are not able to obtain a shell window into the build
farm and do not have
and cannot obtain login credentials into the build server. Thus, permissions on
the build directories
are relevant only to Toaster. The user gets to see what Toaster allows the user
to see based on the
permissions the user has in Toaster.
This is only one use for Toaster and one use case scenario. Of course we can
imagine others.
- fw
-----Original Message-----
From: Bob Cochran [mailto:[email protected]]
Sent: Friday, May 30, 2014 6:26 AM
To: Wymore, Farrell; BARROS PENA, BELEN; DAMIAN, ALEXANDRU; Reyna, David;
[email protected]
Subject: Re: [Toaster] Django user system and permissions
On 05/29/2014 01:46 PM, Wymore, Farrell wrote:
> Hi Bob,
>
> First, none of this is cast in stone. I did an initial investigation a
> few weeks ago and created a prototype implementation. This feature is
> still very much under discussion.
>
> To elaborate a little on Belen's comments:
Thank you Farrell, Belen, and Alex for the thorough replies. I'll follow up
later to some of the questions you posed after I become more familiar with
Toaster on 1.6.
Regarding permissions, the Linux model, and a user getting access to a shell,
it may be prudent to not implement a second set of permissions and just rely on
(query) the OS each time the user makes a request of Toaster. Each link could
trigger a Javascript function that queries the Python server and the server in
turn could query the OS for whether the user has permissions (from the OS) to
execute the link / task. Of course, the server would tailor the links shown on
the Toaster web page based on the permissions granted by the OS (administrator).
This way the permissions would remain consistent if the user switched back &
forth between Toaster and a shell. My fear is that if you have two sets of
permissions, it will create confusion and access control holes for this class
of user (such as myself).
Thanks again,
Bob
>
> -----Original Message-----
> From: Barros Pena, Belen [mailto:[email protected]]
> Sent: Thursday, May 29, 2014 2:54 AM
> To: Bob Cochran; Wymore, Farrell; DAMIAN, ALEXANDRU; Reyna, David;
> [email protected]
> Subject: Re: [Toaster] Django user system and permissions
>
> On 29/05/2014 03:59, "Bob Cochran" <[email protected]> wrote:
>
>>> On 05/28/2014 04:35 PM, Wymore, Farrell wrote:
>>>> I¹ve attached a (short) working paper. This is fairly high level
>>>> but outlines the main ideas and
>>>>
>>>> implementation plan. Everywhere the documents indicates a Œbuild¹,
>>>> substitute Œproject¹. Please
>>>>
>>>> let me know what you think. Thanks.
>>>>
>>>
>>>
>>> Hi Farrell,
>
>> Hi Bob,
>
>> The answers to your questions are... well, that we don't have answers
>> yet
>> :) Just to clarify: access control and permissions are not a key deliverable
>> for the 1.7 release. We'll make them happen if we can, subject to the
>> priority work being done. Some more details below.
>
> This is a feature Wind River will need (likely sooner than later).
> In the current prototype implementation, this feature can be turned off
> easily.
>
>>>
>>> I have a few questions about your document & Toaster in general:
>>>
>>> Will the Toaster permissions correspond in any way to the actual
>>> build folders, or is this just permissions to access specific web
>>> pages and links (e.g., start build)?
>
> No. It is not the intention to mirror the host filesystem permissions. Rather
> the permissions are applied to database objects.
> In the current prototype implementation, the permissions are applied
> to a build object. Permissions can be set such that one user can see and
> manipulate a build while others cannot.
>
> Sometime in the future permissions will likely be applied to projects, as
> Belen indicates below, rather than a single build.
>
>> Personally, I'd like to see permissions based on projects. Projects are
>> coming on the 1.7 release. A project will be a specific configuration you
>> can build against, making changes to it as needed of >course (you might want
>> to change the value of a variable or add a layer or what not). If you have a
>> configuration that you know a few people will need to build against, you
>> give them "build access" to >that project. If you want them to be able to
>> change the configuration, you give them "edit" (or write) access. If you
>> just want them to download the outcome of the builds (a rootfs), you give
>> them >"download" (or read) access.
>
>> I think the Linux file system is very sophisticated, probably a bit too much
>> for a first implementation of access control in a web application.
>> Also, we might find we need different types of permissions other than read
>> and write. But everything is still very much in the air: we are still
>> discussing how to do this.
>
> The linux/unix filesystem is sophisticated but is also one of the simpler
> models. For Toaster, this model accomplishes 2 key things:
> 1) excludes users from builds they should not see/have access to, 2) allows a
> user to share a build with others.
>
>>>
>>> A related question: Is the idea that a toaster user will never grab
>>> a shell?
>
> This would depend on a specific deployment. From a WindRiver point-of-view
> the answer is NO.
>
>> That is an interesting question. I don't think the idea is to prevent people
>> from grabbing a shell: it's about providing alternatives to the shell.
>
>>>
>>> If a user has basic permissions, can a user create a new image
>>> recipe, work directory, and bbappend files to create their own customized
>>> image?
>
>> See above: there might be different kinds of permissions, and permissions
>> could be allocated for a specific configuration (i.e. a project).
> Belen's comment is spot on.
>
>>>
>>> If so, will the permission model also support the amount of
>>> storage available to the user?
>>> You¹ll probably want to prevent a user from creating an infinite
>>> number of new projects until the disks are exhausted.
>
>> This is a very good point: when we design the permissions system, we should
>> keep this in mind.
>
> I'm sure we'll need to impose limits of some kind (or charge real
> money). We haven't explored this question.
>
>>>
>>> Why is the Django admin application not supported in Toaster?
>
> I did investigate the Django admin. There are parts that can be used
> and is part of the prototype implementation. The Django admin is good for
> managing users and authenticating credentials.
> Django also has capabilities which can be grouped together (called
> 'groups' in django) and assigned to an object. This is not the same concept
> as the linux groups which represents one or more users.
> Further, we want to assign permissions to a build/project and check
> this permission against some credential. This is something Django does not do.
>
>> Alex will need to answer this one.
>
>>> I just
>>> started using Toaster (but am a long time user of Django). For
>>> local server use, I'll want to patch in the admin app.
>>>
>>> Lastly, Upon initial review & use, Toaster seems awesome!
>>>
>>> Thank you,
>>>
>>> Bob Cochran
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> toaster mailing list
>>> [email protected]
>>> https://lists.yoctoproject.org/listinfo/toaster
>
>
>
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