Open Stack

Hi

As per the discussion during the keystone IRC meeting yesterday, I have been reviewing the proposals for this functionality.  There have been two objections to the current proposal (which can be found here: https://review.openstack.org/#/c/29781/10), which are:

1) The api changes should allow for a logical, generic future extension for support of inherited roles across all domains etc., should we chose to go that route
2) The use of a single api to list the various grants, filtered by a query string if necessary.

My proposal for handling these two objections is as follows:

1) API extensions.

There are several aspects of inherited roles that we are trying to cement, which are:

a) The are dynamic - i.e. this isn't a case of a short hand for saying add this role to all the current projects in the domain - rather it is a role assignment that is attached to the domain but is added to the effective roles of any project (now and in the future) that exists in this domain
b) The are separate from a role that is on the domain itself - i.e.  we need to ensure that we keep separate inherited and non-inherited roles.
c) Maintain the philosophy that If you can create a role assignment with a given API, there should be an equivalent to read it back and delete it (i.e. you mustn't have the case where, for instance you can list a grant, but can't delete it at the conceptual level)

The current proposal had been to do this by adding an "inherited" component of the url for create, check and delete grants to a domain, e.g.

PUT /domains/{domain_id}/users/{user_id}/roles/{role_id}
PUT /domains/{domain_id}/users/{user_id}/roles/{role_id}/inherited
GET /domains/{domain_id}/users/{user_id}/roles/{role_id}
GET /domains/{domain_id}/users/{user_id}/roles/{role_id}/inherited
DELETE /domains/{domain_id}/users/{user_id}/roles/{role_id}
DELETE /domains/{domain_id}/users/{user_id}/roles/{role_id}/inherited
etc.

A counter proposal has been made to expand this, along this lines of:

Role applicable to all projects within a domain
PUT /domains/{domain_id}/users/{user_id}/roles/{role_id}/projects

Roles inherited by all projects in all domains
PUT /usrs/{user_id}/roles/{role_id}/projects

Roles inherited by all domains, at the domain level
PUT /usrs/{user_id}/roles/{role_id}/domains

While I understand the desire to have extensibility if we wish to provide more "global-ness" of roles, I think the above proposal is less clear about whether these assignments are dynamic (see item a) above).  How about this as a counter proposal:

Role applicable inherited by all projects within a domain (this is the same as the current proposal)
PUT  /domains/{domain_id}/users/{user_id}/roles/{role_id}/inherited

Roles inherited by all projects in all domains - if we were to ever support this (not part of the current proposal)
PUT  /domains/users/{user_id}/roles/{role_id}/inherited

Roles inherited by all domains, at the domain level - if we were to ever support this (not part of the current proposal)
PUT  /domains/users/{user_id}/roles/{role_id}/inherited

To go along with the above, you would have the respective GET, CHECK & DELETE versions of those apis.

2) Single vs multiple apis
I think this comment is actually misplaced in the gerrit review, and is intended to directed at the api extensions I proposed to allow the list of a users "effective" roles on a project (i.e. directly assigned, those by virtue of group membership and inheritance from the parent domain).  For this, I proposed adding an optional "effective" query parameter to each of:

List user's roles on project: `GET /projects/{project_id}/users/{user_id}/roles
List group's roles on project: `GET /projects/{project_id}/groups/{group_id}/roles
Check user's role on project: `GET /projects/{project_id}/users/{user_id}/role/{role_id}
Check group's roles on project: `GET /projects/{project_id}/groups/{group_id}/role/{role_id}

e.g. GET /projects/{project_id}/users/{user_id}/roles?effective
...would get you the effective roles the user has on that project, as opposed to only the directly assigned ones if you issue the call without the "effective" query parameter.

Dolph and I had already been discussing that the existing v3 api of:

GET /users/{user_id}/roles

...which is meant to return all the role assignments for a user, but is in fact broken in the current Grizzly code (it always returns an error).  So I agree with the proposal that we should scrap the "effective" query parameter for the specific list/check calls for the project - and instead properly implement the "get all assignments for a user" call.  I propose the amended spec for this call is:

#### List a user's effective role assignments: `GET /users/{user_id}/role-assignments`

query_string: page (optional)
query_string: per_page (optional, default 30)
query_string: id, project_id, domain_id

Response:

    Status: 200 OK

    [
        {
            "id": "--role-id--",
            "name": "--role-name--",
            "project_id": "--project-id--",
            "source":
            {
                "direct": true,  (optional)
                "domain_inherited: "--domain-id--", (optional)
                "group_membership: "--group-id--" (optional)
            }
        },
        {
            "domain_id": "--domain-id--",
            "id": "--role-id--",
            "name": "--role-name--",
            "source":
            {
                "direct": true, (optional)
                "group_membership: "--group-id--" (optional)
            }
        }
    ]

The "source" structure must have at least one of the values given above (and could have more than one, e.g. both domain_inherited and global_membership for a project where the role is due to a group role that is inherited from the domain).  If were even to support global roles across all domains, then we would extend the "source structure" accordingly.   I'm open to other options for the above format. however, so comments welcome.

Does this sounds like a reasonable plan overall?

Henry