On Thu, 2022-01-20 at 13:23 +0000, Sean Mooney wrote:
On Thu, 2022-01-20 at 09:05 +0900, Takashi Kajinami wrote:
Thank you, Ghanshyam, for your inputs. These are helpful to understand the latest plan.
So I think our question comes back to the original one. Currently keystone allows any of
- system-service
- domain-service
- project-service
- system-admin
- system-member
- system-reader
to validate token but which one is the appropriate one to be used by authtoken middleware ?
Considering the purpose of the service role, the service role is appropriate but it's not yet clear which scope should be used (as is pointed out by Mark from the beginning).
AFAIK token is not a resource belonging to projects so system scope looks appropriate but what is the main intention is to allow project/domain scope ?
a token is really a resouce belownign to a user and that user can be a member of a project or doamin. do we need to enfoce any scope on this endpoint?
the token that the midelware is vlaidating shoudl be suffenct to do the validation since that user shoudl be able to retirve the list of roles and project/domain membership its is part of so i guess im confusted why we woudl not just pass the token to be ckeck as the token the middelware uses and not enforece any scope or role reqiruement on the token validation endpoint
perhaps im missunderstanding and the authtoken middleware is not the middleware that validate the toke is valid and populates the project_id and domain_id /roles in the oslo context object?
by the way im asserting that a GET or HEAD query to
/v3/auth/tokens should not require any scope or role to complete
https://docs.openstack.org/api-ref/identity/v3/?expanded=check-token-detail,...
if the token that is being vlaidated is valid then the request can use the permission on that token to authrise the return of the info if the token is not valid hten it woudl return a 403
openstack uses bearer tokens so the fact that you posess it entirles you to use teh permission allowed by that token.
even a *reader token with no other roles shoudl be able to use the current token to validate itself. so really i dont think this api shoudl require a second token to vouch for it.
i can see some pushing back saying this would weaken the current security model which is valid in which case i woudl proably go with allowing a system-reader token with service roles or something similar. since tokens are nto really proejct or domaing owned but user owned.
By the way, in Puppet OpenStack, we have been using the service"s" project instead of the service project for some reason(which I'm not aware of). So it's helpful for us if we avoid implementing strict limitations to use the service project.
On Thu, Jan 20, 2022 at 1:29 AM Ghanshyam Mann gmann@ghanshyammann.com wrote:
---- On Wed, 19 Jan 2022 08:01:00 -0600 Takashi Kajinami < tkajinam@redhat.com> wrote ----
On Wed, Jan 19, 2022 at 9:22 PM Mark Goddard mark@stackhpc.com wrote: On Wed, 19 Jan 2022 at 11:15, Takashi Kajinami tkajinam@redhat.com
wrote:
Hi,
(The topic doesn't include puppet but ...) I recently spent some time implementing initial support for SRBAC in Puppet OpenStack. You can find details in the etherpad[1] I created as my working note. It includes some items commonly required by all
toolings
in addition to ones specific to puppet. [1] https://etherpad.opendev.org/p/puppet-secure-rbac
Thanks for responding, Takashi - that's useful.
I expect some of them (especially the configuration parameters) would
be used
by TripleO later.
Question: should the role be added with system scope or in the existing service project? The obvious main use for this is token validation, which seems to allow system or project scope.
I'd add one more question which is; Which roles should be assigned for the service users ?
In the project which already implemented SRBAC, system-admin +
system-reader
allows any API calls and works like the previous project-admin.
IIUC the direction of travel has changed, and now the intention is that system-admin won't have access to project-scoped APIs.
Yes, as mark mentioned. And that is the key change from prevous direction. We are isolating the system and project level APIs. system token will be able to perform only system level operation and not allowed to do project level operation. For example: system user will not be allowed to create the server in nova. To have a quick view on those (we have not finished yet in nova), you can check how it will look like in the below series:
https://review.opendev.org/q/topic:%22bp%252Fpolicy-defaults-refresh-2%22+(s...)
You can see the test cases for all four possible configuration combination and what all roles are allowed in which configuration (case 4th is end goal we want to be for RBAC):
- enforce_scope=False + legacy rule (current default policies)
- enforce_scope=False + No legacy rule (enable scope but remove old
policy default) 3. enforce_scope=True + legacy rule (enable scope with old policy default) 4. enforce_scope=True + no legacy rule (end goal of new RBAC)
For token validations system-reader(or service role) would be enough
but there are
some system-admin-only APIs (os-server-external-events API in nova
called by neutron,
Create allocation in placement called by nova or neutron) used for
communications
between services.
The token validation API has the following default policy:
identity:validate_token: (role:reader and system_scope:all) or rule:service_role or rule:token_subject
So system-reader, system-admin or service (any scope) should work. The spec suggests that the service role is intended for use by service to service APIs, in this case the credentials provided in the keystone_authtoken config. I would guess that system scope makes most sense here with the service role, although the rule suggests it would work with project scope and the service role.
I noticed I ignored implied roles... Thanks for clarifying that. I understand and I agree with this. Considering the intention of SRBAC
this would fixbetter with system-scoped, as you earlier mentioned but I'll defer to the others. >
Another thigns to note here is, in Yoga cycle we are doing only system-admin. system-reader, system-member will be done in phase3 which is for future releases (BB).
If we agree system-admin + system-reader is the right set then I'll
update the default role
assignment accordingly. This is important for Puppet OpenStack
because there are implementations
in puppet (which is usually called as providers) to manage some
resources like Flavors,
and these rely on credentials of service users after trying to look
up user credentials.
I think one of the outcomes of this work is that authentication will necessarily become a bit more fine-grained. It might not make sense to have the same role assignments for all users. To your example, I would say that registering flavors should be done by a different user with different permissions than a service user. In kolla-ansible we don't really register flavors other than for octavia - this is up to operators. My main concern was that some service users would require system-admin
butI should have read this part more carefully. https://opendev.org/openstack/governance/src/branch/master/goals/selected/co...
So Assigning the service role (for the proper scope which is asked in
the original thread)is the right way to go. For the provider stuff I'll look into any available option to replace usage of serviceuser credential but that's specific to Puppet which we can ignore here in this discussion.
right, once we have service role implemented then we will have clear way on how services will be communicating to other services APIs.
-gmann
Takashi
On Wed, Jan 19, 2022 at 7:40 PM Mark Goddard mark@stackhpc.com
wrote:
Hi,
If you haven't been paying close attention, it would be easy to miss some of the upcoming RBAC changes which will have an impact on deployment projects. I thought I'd start a thread so that we can
share
how we are approaching this, get answers to open questions, and ideally all end up with a fairly consistent approach.
The secure RBAC work has a long history, and continues to evolve. According to [1], we should start to see some fairly substantial changes over the next few releases. That spec is fairly long, but worth a read.
In the yoga timeline [2], there is one change in particular that has an impact on deployment projects, "3. Keystone enforces scope by default". After this change, all of the deprecated policies that many still rely on in Keystone will be removed.
In kolla-ansible, we have an etherpad [5] with some notes, questions and half-baked plans. We made some changes in Xena [3] to use system scope in some places when interacting with system APIs in Ansible tasks.
The next change we have staged is to add the service role to all service users [4], in preparation for [2].
Question: should the role be added with system scope or in the existing service project? The obvious main use for this is token validation, which seems to allow system or project scope.
We anticipate that some service users may still require some project-scoped roles, e.g. when creating resources for octavia. We'll deal with those on a case by case basis.
In anticipation of keystone setting enforce_scope=True and removing old default policies (which I assume effectively removes enforce_new_defaults?), we will set this in kolla-ansible, and try to deal with any fallout. Hopefully the previous work will make this minimal.
How does that line up with other projects' approaches? What have we
missed?
Mark
[1]
https://opendev.org/openstack/governance/src/branch/master/goals/selected/co...
[2]
https://opendev.org/openstack/governance/src/branch/master/goals/selected/co...
[3]
https://opendev.org/openstack/kolla-ansible/commit/2e933dceb591c3505f35c2c1d...
[4] https://review.opendev.org/c/openstack/kolla-ansible/+/815577 [5]
https://etherpad.opendev.org/p/enabling-system-scope-in-kolla-ansible