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From Emmanuel Lecharny <elecha...@gmail.com>
Subject Re: [Triplesec] [AuthZ] Environments and Groups
Date Wed, 31 Oct 2007 19:34:34 GMT
Comments at the end...


David Jencks wrote:
>
> On Oct 30, 2007, at 9:19 PM, Alex Karasulu wrote:
>
>> Hi David,
>>
>> On 10/30/07, *David Jencks* <david_jencks@yahoo.com 
>> <mailto:david_jencks@yahoo.com>> wrote:
>>
>>
>>     On Oct 24, 2007, at 10:29 AM, Alex Karasulu wrote:
>>
>>     > Environments and Groups
>>     > -------------------------------------
>>     >
>>     > When releases are ready for deployment, systems and applications
>>     > must be put into
>>     > some operating environment.  Within any environment identities will
>>     > exist; some
>>     > will be users, some services and some will be specific hosts. These
>>     > principals for
>>     > the sake of manageability are often categorized together into
>>     > logical associations.
>>     > By grouping identities together, administrators can handle them as
>>     > a single entity
>>     > where the same set of tasks may apply to the group whatever those
>>     > management
>>     > operations may be.
>>     >
>>     > Although groups are designed by administrators to simplify and
>>     > reduce their workload,
>>     > it's no coincidence that these groups are highly dependent on an
>>     > organization's structure
>>     > or the processes within an organization.  General groups may exist
>>     > for the entire
>>     > organization.  More specific groups will exist for the departments
>>     > of an organization.
>>     > When processes drive the creation of groups, membership is a based
>>     > on similar functions
>>     > required of a group's members.  Sometimes processes are isolated to
>>     > a division, but more
>>     > often than not, processes span across divisions leading to the
>>     > creation of cross
>>     > divisional groups.
>>     >
>>
>>     I think this says that there's a set of Users (or principals?) we
>>     need to keep track of and that if there are more than a few users we
>>     will want to treat lots of them the same way.   
>>
>>
>> Yes I was referring specifically to groups of users.
>>
>> But not suggesting that "we" store group definitions and their 
>> members in Triplesec
>> necessarily.  Users might do so with a Triplesec only solution if 
>> external systems are not
>> to be utilized.  Most likely we will be dealing with the mixed case 
>> where users and groups
>> are defined in Triplesec and within external systems.  Triplesec will 
>> need to use some
>> techniques we can discuss later to refer to these externally defined 
>> entities.
>>
>>     Since we are
>>     discussing authorization here I think this means that there are sets
>>     of users we want to grant the same permissions with a single simple
>>     operation.
>>
>>
>> Well I'm just talking about the purpose of grouping in general.  I 
>> think we can get
>> into this aspect in the role assignments thread. For now groups are 
>> just sets of
>> objects although I refer to user groups specifically above.
>>
>>     > We extract more glossary definitions:
>>     >
>>     > Group:
>>     >    A set of distinctly identifiable entities which are
>>     > categorically alike within an
>>     >    organization, organizational unit or with respect to some
>>     > organizational process.
>>     >
>>     I'm not sure what this means beyond "a group is a set of  users".
>>
>>
>> Well you can group many things besides just human users.  We can group
>> printers, processes, even organizations and their divisions etc.
>>
>>     I'm sure everyone agrees that we need an easy way to take users who
>>     need to do the same kind of stuff and treat them all in the same
>>     way.  
>>
>>
>> Yes!  That's it.  This is all we need to agree on in this thread.
>>
>>     Even though "groups" are in most or all existing systems I'm
>>     not sure our model or our discussion needs a separate concept from
>>     "roles" to handle them.  
>>
>>
>> No! It was going so well then this :). Groups have no security 
>> connotation associated
>> with them.  They're just sets or collections of objects.  Some groups 
>> may have a
>> uniqueness requirement so they're sets of objects.  Others don't so 
>> they're collections
>> of objects.
>>
>> Groups can be extended in several ways and we can talk about that 
>> later but as a teaser
>> we have the following concepts/extensions:
>>
>>    o nested groups
>>    o static groups
>>    o dynamic groups
>>
>>     To me it seems that conceptually when you
>>     start with users and ask "who does the same kind of job" you think
>>     "group" but when you start with permissions and ask "what permissions
>>     do we need to group together to get a useful task done" you think
>>     "role".
>>
>>
>> You're mixing concepts here.  I will state what I consider to be some 
>> pretty concrete
>> and simple facts about groups and you can refute or agree with them:
>>
>> (1) A group is a set or collection of objects.
>
> I don't mean to quibble and I don't see how it makes any difference to 
> meaning but what is the difference?
>
>> (2) A group does not have any security connotation associate with 
>> it's definition. It's
>>      merely an amalgamation.
>
> <flame>In that case why are we talking about it in the context of an 
> authz manager?</flame>
>> (3) Groups are often defined to reduce the amount of management 
>> overhead by enabling
>>      administrators to apply one operation to a group of N members, 
>> instead of N
>>      operations on each member.  The drive to maximize this benefit 
>> over time brings about
>>      different kinds of groupings that naturally align with processes 
>> and organizational structures.
>> (4) A group need not be homogeneous.
>
> Not sure what you mean by this.
>
> I don't argue with any of this but don't see how it relates to whether 
> "group" is an appropriate concept for an RBAC discussion.  I've never 
> denied that existing systems have groups defined in them and we have 
> to work with these existing systems.  Just because data is stored in 
> something called a "group" doesn't, to me, mean we need to call it a 
> group in our model or code.
>>
>> Not sure about the value #3 provides to the discussion but it sounds 
>> good to say :-D.
>
> I like #3 the best myself :-)
>
> thanks
> david jencks
>
>>
>> Alex
>>
>

Well, I see there are two different visions about what 'groups' are and 
how usefull they are in a Authz scope and how they can be seen as 
'roles' in this scope.

My personal opinion is that normal humans just simply have it hard to 
see all the servers of building A as a role. They usually point them as 
'the bloody group of servers in building A are randomly rebooting every 
day ' ... Or 'the group of printers in building B which roles is to 
print payroll are totally outdated'.

Seriously, I would favor the 'group' usage when it comes to real life 
entities (like users, printers, hosts) because this is what admin are 
manipulating. It's not a concept, it's a collection of existing devices 
(and humans :).

We can abstract those entities and say they are just defined by their 
role (a DBA admin, a J2EE developper, a cost-killer, etc), but it's 
easier to see them as part of groups (the developpers, the 
admininstrators, the cost-killers, etc ...) with specific roles (A J2EE 
developper, a DBA admin etc ...)

IMHO, of course :)



--
cordialement, regards,
Emmanuel L├ęcharny
www.iktek.com
directory.apache.org



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