[security-dev] PicketLink IDM JPA Identity Store
sbryzak at redhat.com
Mon Oct 8 19:24:12 EDT 2012
The reason I advised that we base the JPA implementation on Seam's
JpaIdentityStore was not one to do with pride, but because its design
has been shaped by many years of developer feedback. I've got no
problem with Pedro's code (I think it's quite good actually) however the
design fails to address a number of requirements. Let's go through a
few of them in more detail:
1. Hard coded entities
This is a problem for a number of reasons. First and foremost, it
doesn't allow a developer to BYO schema. Many projects share user
databases, or are based on legacy systems that cannot be modified.
There may be strict naming conventions in place for table and column
names. It might be simply the case that the developer needs to model
their schema in a particular way to meet certain business requirements.
Whatever the reason, it is very clear that we cannot dictate the
database schema to the developer. We can certainly make
recommendations, however this should be done via documentation, and
possibly in an example.
This also stems from having a hard coded schema. Many projects may
require users to authenticate against an LDAP directory, but authorize
against a database. One of the great ideas from Bolek's original PLIDM
implementation was that of FeatureSets, basically metadata which
reflects which identity management capabilities a particular
IdentityStore implementation supports. It allows us to store users in
one identity store, and group and role memberships in another. Also,
what happens when an application wants to be purely LDAP based, does
Hibernate still try to create (or expect the existence of) the
corresponding tables for the hard coded entity beans? What if there is
This particular feature isn't present in Seam, however the intent is to
support it in PicketLink. To summarise, rather than creating a new
User, Group or Role instance (or their various memberships) every single
time the IdentityStore would normally need to do this, we use a single
cache (distributed in the case of clustered applications) to store these
identity objects and perform the lookup from the cache instead. This
isn't possible to achieve when we have hard coded entities that
implement the identity model interfaces. This feature requires an
intricate coupling between IdentityManager, IdentityStore and the cache
4. CDI awareness
We need to develop this module so that it will run in an SE environment
so that the AS team (and others) can use it, however we need to also
keep in mind that we need to integrate it with CDI, and the design
should reflect that. JPACallback and JPATemplate seem to add
unnecessary complexity which in the end still boils down to one
EntityManager instance per JPAIdentityStore. I honestly think the
JPAIdentityStore implementation should be stateless, in that one
instance can service multiple (concurrent) requests (not to mention that
configuration is an expensive operation). We also need to also keep in
mind that the EntityManager could have any type of scope, with the most
obvious ones being request or conversation scoped.
I'm happy to discuss these further, however I hope that it's convinced
everyone that we need to reconsider the current design.
On 09/10/12 02:30, Anil Saldhana wrote:
> I want to offer continued discussion on the JPA implementation in the
> IDM project.
> The work that Pedro did is restored here in the following workspace:
> A testcase that is useful for JPA implementation in IDM is:
> It is the exact mirror of the LDAP implementation:
> These two implementations have very minimal user configuration.
> The challenge is when users bring in complex database schemas and LDAP
> DITs into operation. But the goal of balancing complexity with
> usability is a tough one.
> On 09/06/2012 10:13 AM, Anil Saldhana wrote:
>> Similar challenges exist for LDAP bindings also, since user LDAP DITs
>> may be different. But we have to balance complexity with usability. :)
>> On 09/06/2012 07:37 AM, Pedro Igor Silva wrote:
>>> Ok. I'll take a look how he took care of that.
>>> Pedro Igor
>>> ----- Original Message -----
>>> From: "Anil Saldhana" <Anil.Saldhana at redhat.com>
>>> To: security-dev at lists.jboss.org
>>> Sent: Wednesday, September 5, 2012 6:52:35 PM
>>> Subject: [security-dev] PicketLink IDM JPA Identity Store
>>> Shane just referred me to the following:
>>> Can you adapt your work to incorporate all facets of this Seam work?
>>> Shane says users have varying db schema structures and the JPA
>>> implementation in seam3 took care of the nuances.
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