Open Stack

On 12/05/15 13:06, Georgy Okrokvertskhov wrote:
> There is one thing which still bothers me. It is authentication. Right
> now with separate RabbitMQ instance we keep VMs authentication isolated
> from OpenStack infra.
> This is still a problem if you want to use webhooks (Heat autoscaling,
> Murano actions) via our own authentication models. If we plan to use
> Zaqar it will be interesting to know how Zaqar solves this issue.

Aha, if you'd read my blog post you would know the answer ;)

There's no specific provision for this in Zaqar at the moment AFAIK. The 
problem is really Keystone: it was never designed for authenticating 
applications to the cloud, only real live users.

We need to fix this, in Keystone & Oslo, for the benefit of all 
application-facing services. Some work has already started:

- Keystone can now support separate backends for separate domains, so 
even if you are backed by read-only LDAP you can create service users in 
a separate DB-backed domain: 
http://adam.younglogic.com/2014/08/getting-service-users-out-of-ldap/

- Work is planned on "Dynamic Policy" to make the authorisation model 
more powerful: 
http://adam.younglogic.com/2014/11/dynamic-policy-in-keystone/

I'm not sure that this goes far enough though (although I don't 
completely grok the implications of Dynamic Policy). We really want 
users to be able to define their own policy for application accounts 
that they create, and at an even more fine-grained level, so a common 
library for this sort of authorisation would be helpful.

> Frankly, I don't think that this is a good idea to use Keystone
> credentials or tokens for MQ clients on VMs. This topic, probably,
> deserves its own e-mail thread.

Keystone credentials _are_ the answer, but they must not be the *user's* 
Keystone credentials.

I can tell you how Heat does this right now for authenticating 
application callbacks for WaitConditions. It's not exactly pretty, but 
it works. Basically we create the application users in a separate domain 
and then do extra authorisation checks ourselves. Steve Hardy wrote a 
comprehensive summary on his blog: 
http://hardysteven.blogspot.com/2014/04/heat-auth-model-updates-part-2-stack.html

So the mechanisms are there. In the short term we'd need some 
cross-project co-operation to define a system through which we can do 
this across projects (i.e. Murano or any other service can create a user 
and have Zaqar authorise it for listening on a particular queue). Maybe 
this is an extra parameter when creating a queue in Zaqar to also create 
a user account in a separate domain (the way Heat does) with permission 
to send and/or receive only on that particular queue and return its 
credentials. That would be easier to secure and easier to implement than 
having other services create the user accounts themselves.

In the medium term hopefully we'll be able to come up with a less hacky 
solution that uses Oslo libraries to manage all of the user creation and 
authorisation.

> It will be interesting to discuss this with Keystone team. What is it is
> possible to have a token which is restricted to be authenticated to
> specific API URL like  GET /v1/queues/<queue-id>/

Yes, we should definitely discuss this with the Keystone team and make 
sure they're getting feedback from all of the many groups who need it so 
that they can prioritise the work appropriately :)

cheers,
Zane.

>
> Thanks
> Gosha
>
>
>
> On Tue, May 12, 2015 at 8:58 AM, Fox, Kevin M <Kevin.Fox at pnnl.gov
> <mailto:Kevin.Fox at pnnl.gov>> wrote:
>
>     +1
>     ________________________________________
>     From: Zane Bitter [zbitter at redhat.com <mailto:zbitter at redhat.com>]
>     Sent: Monday, May 11, 2015 6:15 PM
>     To: openstack-dev at lists.openstack.org
>     <mailto:openstack-dev at lists.openstack.org>
>     Subject: Re: [openstack-dev] [Murano] [Mistral] SSH workflow action
>
>     Hello!
>
>     This looks like a perfect soapbox from which to talk about my favourite
>     issue ;)
>
>     You're right about the ssh idea, for the reasons discussed related to
>     networking and a few more that weren't (e.g. users shouldn't have to and
>     generally don't want to give their private SSH keys to cloud services).
>     I didn't know, or had forgotten, about the message queue implementation
>     in Murano and while I think that's the correct shape for the solution,
>     as long as the service in question is not multi-tenant capable it's a
>     non-starter for a public clouds at least and probably many private
>     clouds as well (after all, if you don't need multi-tenancy then why are
>     you using OpenStack?).
>
>     There's been a tendency within the application-facing OpenStack projects
>     to hack together whatever local solutions to problems that we can in
>     order to make progress without being held up by other projects. Let's
>     take a moment to acknowledge that Heat is both the earliest and the
>     biggest offender here, and that I am as culpable as anyone in the
>     current state of affairs. There are multiple reasons for how things have
>     gone - part of it is that it turned out we developed services in the
>     wrong order, starting at too high a level. Part of it, frankly, is due
>     to that element of the community that maintains a hostile position
>     toward application-facing services and have used their influence in the
>     community to maintain a disincentive against integrating projects
>     together.[1] (If deployment of your project is discouraged that's one
>     thing, but if it depends on another project whose deployment is also
>     being discouraged then the hurdle you have to jump over is twice the
>     height.)
>
>     That said, I think we're at the point where we are hurting ourselves
>     more than anyone else is by failing to come up with coherent,
>     cross-project solutions.
>
>     The problem articulated in this thread is not an isolated one. It's part
>     of a more general pattern that affects a lot of projects: we need a way
>     for the cloud to communicate to applications running in it. Angus
>     started a recent discussion of this already on the list.[2] The
>     requirements, IMHO, are roughly:
>
>        * Reliability - we must be able to guarantee delivery to applications
>        * Asynchrony - the cloud cannot block on user-controlled processes
>        * Multitenancy - this is table stakes for OpenStack
>        * Access control - even within tenants, we need to trust guest VMs
>     minimally
>
>     IMNSHO Zaqar messages are the obvious choice for the transport here. (Or
>     something very similar in shape to Zaqar - but it'd be much better to
>     join forces with the Zaqar team to improve it where necessary than to
>     start a new project.) I really believe that if we work together to come
>     up with consistent solutions to these problems that keep popping up
>     across OpenStack, we can prove wrong all the naysayers who think that
>     application-facing services are only for proprietary clouds. I wrote up
>     my vision for why that's important and what there first steps are here:
>
>     http://www.zerobanana.com/archive/2015/04/24#a-vision-for-openstack
>
>     Note that there are some subtleties that not everyone here will be able
>     to contribute directly to fixing. For example, as I highlight in that
>     post, Keystone is built around the concept that applications never talk
>     to the cloud. But there are lots of other things people can work on now
>     that would really make a big difference. For Mistral and Murano
>     specifically, and in rough order of priority:
>
>        * Add an action in Mistral for sending a message to a Zaqar queue.
>     This is easy and there's no reason you couldn't do it right now.
>        * Encourage any deployers and distributors you know (or, ahem, may
>     work for ;) to make Zaqar available as an option.
>        * Add a way to trigger a Mistral workflow with a Zaqar message. This
>     is one piece in the puzzle to build user-configurable messaging flows
>     between OpenStack services.[3]
>        * Make Zaqar an alternative to Rabbit for communicating to the Murano
>     agent.
>        * Use your experience in implementing notifications over email
>     and the
>     like in Mistral to help the Zaqar team to add the notification features
>     they've long been planning. These could take the form of microservices
>     listening on a Zaqar queue. You get the reliable, asynchronous queuing
>     semantics for free and *every* service and user can benefit from
>     your work.
>
>     Imagine if there were one place where we implemented reliable queuing
>     semantics at cloud scale, and when we added e.g. long-polling or
>     WebSockets everyone could benefit immediately.[4] Imagine if there were
>     one place for notifications, at cloud scale, for operators to secure.
>     (How many webhook implementations are there in OpenStack right now? How
>     many of them are actually secure against malicious users?) One format
>     for messages between services so that users can connect up their own
>     custom pipelines. We're not that far away! All of this is within reach
>     if we work together.
>
>     Thanks for reading. Please grab me at summit if you want to know more; I
>     am always happy to bend the ear of anyone who will listen at length on
>     this topic. As usual, I'll be the tall dude with the weird accent ;)
>
>     cheers,
>     Zane.
>
>
>     [1] https://review.openstack.org/#/c/180112/
>     [2]
>     http://lists.openstack.org/pipermail/openstack-dev/2015-April/060748.html
>     [3]
>     http://lists.openstack.org/pipermail/openstack-dev/2015-April/062617.html
>     [4]
>     http://lists.openstack.org/pipermail/openstack-dev/2015-April/062619.html
>
>
>     On 06/05/15 11:42, Filip Blaha wrote:
>      > Hello
>      >
>      > We are considering implementing  actions on services of a murano
>      > environment via mistral workflows. We are considering whether mistral
>      > std.ssh action could be used to run some command on an instance.
>     Example
>      > of such action in murano could be restart action on Mysql DB service.
>      > Mistral workflow would ssh to that instance running Mysql and run
>      > "service mysql restart". From my point of view trying to use SSH to
>      > access instances from mistral workflow is not good
>      > idea but I would like to confirm it.
>      >
>      > The biggest problem I see there is openstack networking. Mistral
>     service
>      > running on some openstack node would not be able to access
>     instance via
>      > its fixed IP (e.g. 10.0.0.5) via SSH. Instance could accessed via ssh
>      > from namespace of its gateway router e.g. "ip netns exec
>     qrouter-... ssh
>      > cirros at 10.0.0.5 <mailto:cirros at 10.0.0.5>" but I think it is not
>     good to rely on implementation
>      > detail of  neutron and use it. In multinode openstack deployment it
>      > could be even more complicated.
>      >
>      > In other words I am asking whether we can use std.ssh mistral
>     action to
>      > access instances via ssh on theirs fixed IPs? I think no but I would
>      > like to confirm it.
>      >
>      > Thanks
>      > Filip
>      >
>      >
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>
>
> --
> Georgy Okrokvertskhov
> Architect,
> OpenStack Platform Products,
> Mirantis
> http://www.mirantis.com <http://www.mirantis.com/>
> Tel. +1 650 963 9828
> Mob. +1 650 996 3284
>
>
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