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Re: [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 <mailto: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 <mailto: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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