openstack team mailing list archive

["Yee, Guang" <guang.yee@xxxxxx>]

I agree with Adam.

 

+1 on Default Domain.

 

When we first introduced the Keystone Domains BP, things such as usability,
flexibility, consistency, and backward compatibility played a critical role
in our design. Domains are basically containers for users and projects
(formerly tenants) for administrative purposes and are not visible to
public/service APIs. Therefore, other OS services need not be domain-aware. 

 

Domains does not affect (public) API backward compatibility, as far as OS
services are concerned. Therefore, the globally uniqueness requirement for
users and projects remains.

 

If you have no need for domains, you don't have to change anything. Default
Domain is invisible to the V2 APIs.

 

If you are using domains and your user ID/names are globally unique, you
don't have to change anything.

 

If you are using domains and are integrating with an existing identity
management system backend such as Active Directory, you can still achieve
globally uniqueness by having domain name appended to username (i.e.
jdoe@acme), or simply using user email as user name for authentication. And
I am sure there are other solutions ways as well.

 

If you have a use case that has not been covered by the above, please let us
know. Or please feel free to join us on the weekly Keystone meeting.

 

 

Guang

 

 

 

From: openstack-bounces+guang.yee=hp.com@xxxxxxxxxxxxxxxxxxx
[mailto:openstack-bounces+guang.yee=hp.com@xxxxxxxxxxxxxxxxxxx] On Behalf Of
Adam Young
Sent: Tuesday, October 30, 2012 6:34 AM
To: openstack@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Openstack] [keystone] Domain Name Spaces

 

On 10/30/2012 04:00 AM, Henry Nash wrote:

Gabriel, 

 

So I think you are right to ask that this is made clear and concrete - I'll
work with the core contributors of Keystone to make it so.

 

To your specific point:

- Let's call the initial Domain, the "Global Domain", rather than the
default domain

No.  It is default.  It is not global.  The other domains do not nest inside
this domain.  Calling it the Global domain is confusing.  I would accept:
unnamed domain, or implicit domain,  but don't think either of those are an
improvement to default.




- If the Cloud Provider doesn't explicitly create any domains, then
everything exists in the Global Domain.  There is no need to specify a
domain in any calls, since everything will default to the Global domain.
The v2 API will work just fine (which knows nothing about domains)

That is correct



- If they do create some domains, then they indicate (on creation) whether
each of these share the namespace of the Global domain, or have their own
private namespace.  

No.  Domain are non-overlapping sets.



- If all of these new domains were specified as shared then all user and
tenant names are still globally unique.  A caller still does not technically
need to specify a domain, although scoping things down to a domain (or of
course project) is likely for most operations (just like it is today)

I fail to see the benefit.



- If, however, some of these new domains were specified as private then any
users who are part of a private domain must specify the domain in order to
authenticate.  By design, authentication will fail if they don't specify a
domain (since you won't exist in the global domain).  Once a user in a
private domain is authenticated, they are scoped to that domain.
[implementation: we need to work out whether the domainID is encoded in the
token - this is my assumption since this means the Domain Name/ID is NOT
required for subsequent requests....and validation, by Keystone, can still
be achieved ]

We are reimplementing tokens/projects here.  



- It is perfectly possible (but of course up to the Cloud Provider) to
support a mixture of shared and private domains (representing different
customer types)....but the point being that the Cloud Provider will tell
their customers how they should access they system (i.e. provide them with
any domain specification that may or may not be required).


I think that this complicates things.  I would instead recommend that a
provider either go with a single domain or explicit domaiuns, as mixing the
two is wierd, but some installations will need to make their existing
deployments work.

I like the idea that the domain will be implicit from the hostname of the
web front end, and also possibly of a Keystone endpoint.  This can be done
with vhosts for Apache, and a simple config value for Eventlet.





 

Very keen to hear other concerns you may have.

 

Henry

On 27 Oct 2012, at 21:22, Gabriel Hurley wrote:





There are various options for how Horizon can handle the UX problems
associated with adding additional domains. Making it a part of the URL is
one which could be supported, but I'm not inclined to make that the only
method. The implementation details can be hashed out when we get there.

 

I am more concerned about the experience for CLI/API users; adding more
parameters they have to pass is quite unfriendly. And I have to say that
Keystone's track record for handling "default" options has been quite poor
(see "default tenant"). The mixed support for lookups via ID vs. name is
also a mess. There needs to be consistency around what is unique and in what
scope (which is where this thread started). So far I haven't heard a
concrete answer on that.

 

For example, if tenants uniqueness is scoped to a domain, and lookups via
tenant name are possible, and there's a default domain. well haven't you
just painted yourself into a corner where tenant names in the default domain
must be unique while names in any other domain do not? It's these kinds of
issues that need to really be thought through.

 

-          Gabriel

 

From: openstack-bounces+gabriel.hurley=nebula.com@xxxxxxxxxxxxxxxxxxx
[mailto:openstack-bounces+gabriel.hurley=nebula.com@xxxxxxxxxxxxxxxxxxx] On
Behalf Of Adam Young
Sent: Friday, October 26, 2012 4:19 PM
To: Henry Nash
Cc: OpenStack Development Mailing List; openstack@xxxxxxxxxxxxxxxxxxx
(openstack@xxxxxxxxxxxxxxxxxxx)
Subject: Re: [Openstack] [keystone] Domain Name Spaces

 

On 10/26/2012 07:17 PM, Henry Nash wrote:

So to pick up on a couple of the areas of contention:

 

a) Roles.  I agree that role names must stay globally unique.  One way of
thinking about this is that it is not actually keystone that is creating the
"role name space" it is the other services (Nova etc.) by specifying roles
in their policy files.  Until those services support domain specific
segmentation, then role names stay global.

 

b) Will multi-domains make it more complicated in terms of authorisation -
e.g. will the users have to input a Domain Name into Horizon the whole time?
The first thing I would say is that if the cloud administrator has create
multiple domains, then the keystone API should indeed require the domain
specification.  However, that should not mean it should be laborious for a
Horizon user.  In the case where a Cloud Provider has created domains to
encapsulate each of their customers - then if they want to let those
customer use horizon as the UI, then I would think they want to be able to
give each customer a unique URL which will point to a Horizon that "knows
which domain to go to".

Yes, I think that this is the solution.  It will involve HTTPD virtual
hosts, and horizon can then get an additional config parameter
"keystone_domain" as part of the wsgi config.






 Maybe the url contains the Domain Name or ID in the path, and Horizon pulls
this out of its own url (assuming that's possible) and hence the user is
never given an option to chose a domain.  A Cloud Admin would use a "non
domain qualified url" to get to Horizon (basically as it is now) and hence
be able to see the different domains.  Likewise, in the case of where the
Cloud Provider has not chosen to create any individual domains (and is just
running the cloud in the default domain), then the  "non domain qualified
url" would be used to a Horizon that only showed one, default domain and
hence no choice is required.

 

 

Henry

 

On 26 Oct 2012, at 17:31, heckj wrote:






Bringing conversation for domains in Keystone to the broader mailing lists.

 

 

On Oct 26, 2012, at 5:18 AM, Dolph Mathews <dolph.mathews@xxxxxxxxx> wrote:

I think this discussion would be great for both mailing lists.


 

-Dolph




On Fri, Oct 26, 2012 at 5:18 AM, Henry Nash <henry.nash@xxxxxxx> wrote:

Hi

 

<Not sure where best to have this discussion - here, as a comment to the
v3api doc, or elsewhere - appreciate some guidance and will transfer this to
the right place>

 

At the Summit we started a discussion on whether things like user name,
tenant name etc. should be globally unique or unique within a domain.  I'd
like to widen that discussion to try and a) agree a direction, b) agree some
changes to our current spec. Here's my view as an opening gambit:

 

- When a Keystone instance is first started, there is only one, default,
Domain.  The Cloud Provider does not need to create any new domains, all
projects can exist in this default domain, as will the users etc.  There is
one, global, name space.  Clients using the v2 API will work just fine.

 

+1

 

Very much what we were thinking for the initial implemenation and rollout to
make it backwards "compatible" with the V2 (non-domain) core API






- If the Cloud Provider wants to provide their customers with regions they
can administer themselves and be self-contained, then they create a Domain
for each customer.  It should be possible for users/roles to be scoped to a
Domain so that (effectively) administrative duties can be delegated to some
users in that Domain.  So far so good - all this can be done with the v3
API.

 

Not clear on if you're referring to endpoint regions, or just describing
domain isolation?

 

I believe you're describing the key use cases behind the domains mechanism
to begin with - user and project partitioning to allow for administration of
those to be clearly "owned" and managed appropriately.

 






- We still have work to do to make sure items in other OS projects that
reference tenants (e.g. Images) can take a Domain or Project ID, but we'll
get to that soon enough

 

Everything will continue to work with projects, but once middleware starts
providing a DOMAIN_ID and DOMAIN_NAME to the underlying service, it'll be up
to them to take advantage of it. Images per domain is an excellent example
use case.






 

- However, Cloud Providers want to start enabling enterprise customers to
run more and more of the workloads in OpenStack clouds - over and above, the
smaller sized companies that are doing this today.  For this to work, the
encapsulation of a Domain need, I think, to be able to be stricter - and
this is where the name space comes into play.  I think we need to allow for
a Domain to have its own namespace (i.e. users, roles, projects etc.) as an
option.  I see this as a first step to allowing each Domain to have its own
AuthZ/N service (.e.g external ldap owned and hosted by the customer who
will be using the Domain)

 

Implementation:

 

- A simplistic version would just allow a flag to specified on Domain
creation that said whether this a "private" or "shared" Domain.  Shared
would use the current global name space (and probably be the default for
compatibility reasons).

 

I like the direction of this -- need to digest implications :)

 

I like the idea conceptually - but let's be clear on the implications to the
end users:

 

Where we're starting is preserving a global name space for project names and
user names. Allowing a mix of segregated and global name spaces imposes a
burden of additional data being needed to uniquely place authentication and
authorization.

 

We've been keeping to 2 key pieces of info (username, password) to get
authenticated - and then (via CLI or Horizon dashboard) you can choose from
a list of protential projects and carry on. In most practical circumstances,
any user working primarily from the CLI is already providing 3-4 pieces of
information:

 

* username

* password

* tenant name

* auth_url

 

to access and use the cloud.

 

By allowing domains to be their own namespaces, we're adding another element
that will be absolutely required to identify the person authenticating:

 * domain name

 

implying a cascade of changes to the user experience all the way down
through horizon.

 






- A more flexible approach would be to allow the specification of where the
various sub-services of Keystone (e.g. AuthN/Z, Service Catalogue, Resources
(i.e Users, Projects)) are hosted.  The defaults would all point back to the
default domain (i.e. are global and shared), but instead could be specified
as "self" (I.e. the new Domain), or, in the future, some other external
location, e.g. for a remote ldap.

- As an aside, this multi-name space model could also allow the Cloud
Provider their own name space, separate from their customers - i.e. they
will have a need to create admins who can just create domains and on-board
customers into those domains.  These users & roles could exist in the
default domain, while all the customers' users/roles exist solely within
their own domains.

- One potential problem I do see is with roles.  Today, the role name is, if
I understand it correctly, a kind of shared secret between, other services
and Keystone - e.g. it is the actual name of a given role, say
"ProjectAdmin" , that must match in, say, the Nova policy file and the role
assignment in Keystone (please correct me if I have this wrong).

 

You're 100% correct.

 

How would that work if the role names were not unique across Domains?

 

Not that we would want admins to ever see Role ID's, or edit policy files
with role ID's, but they provide a potential solution.

 

The different role names would need to be accounted for in the policy files
the way they're set up today - the enforcement there is all at the service
level. There's no current provision for evaluating policy differently based
on domain. While that's possible, it sounds like a tremendous cascade of
additional complication, as the policy, and roles, are all set up and
managed by deployers.

 

I think this might be an interesting addition in the future, but want to
keep the initial implementation and roll-out of the policy mechanisms and
domains consistent and simple for a first roll-out iteration.

 

What is the desired functionality for a Cloud Provider wanting to give their
enterprise customers this level of flexibility - will they have dedicated
Nova endpoints anyway?  Sounds too rigid.  This might tie into another bp we
are working on at IBM in terms of using Availability zones to allow Cloud
Providers to divide up their compute resources in a more flexible way.

- Finally, I wanted to raise the subject of whether we should make it a goal
to remain compatible with the v2 API once the cloud provider starts creating
additional domains.

 

Joe and I briefly discussed this at the summit. As a migration to v3, we'd
obviously be creating the default domain and mapping all existing
users/projectse/etc to it. I'd be fine if the v2 implementation ONLY
interacted with resources in that default domain; i.e. if you want to use
domains, upgrade to a v3 client.

 

As stated above, if just the default domain is being used, then fine.  And
while I agree that, technically, the v2 API should still work with the above
if all the other domains point back to the default domain for their
sub-services - it feels overly flexible (and maybe wrong conceptually) to
support v2 semantics across a multi-domain installation.

 

+1

 

 

Interested in everyone else's view.

 

Henry

 

 

 

 

 






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