[openstack-dev] [tripleo] service validation during deployment steps

Arkady_Kanevsky at DELL.com Arkady_Kanevsky at DELL.com
Tue Aug 2 13:17:01 UTC 2016

What about ability of service expert to plug-in remediation module?
If remediation action succeed - proceed, if not then stop.
Remediation module can be extended independently from main flow.

-----Original Message-----
From: Steven Hardy [mailto:shardy at redhat.com]
Sent: Wednesday, July 27, 2016 3:26 AM
To: OpenStack Development Mailing List (not for usage questions)
Subject: Re: [openstack-dev] [tripleo] service validation during deployment steps

Hi Emilien,

On Tue, Jul 26, 2016 at 03:59:33PM -0400, Emilien Macchi wrote:
> I would love to hear some feedback about $topic, thanks.

Sorry for the slow response, we did dicuss this on IRC, but providing that feedback and some other comments below:

> On Fri, Jul 15, 2016 at 11:31 AM, Emilien Macchi wrote:
> > Hi,
> >
> > Some people on the field brought interesting feedback:
> >
> > "As a TripleO User, I would like the deployment to stop immediately
> > after an resource creation failure during a step of the deployment
> > and be able to easily understand what service or resource failed to
> > be installed".
> >
> > Example:
> > If during step4 Puppet tries to deploy Neutron and OVS, but OVS
> > fails to start for some reasons, deployment should stop at the end
> > of the step.

I don't think anyone will argue against this use-case, we absolutely want to enable a better "fail fast" for deployment problems, as well as better surfacing of why it failed.

> > So there are 2 things in this user story:
> >
> > 1) Be able to run some service validation within a step deployment.
> > Note about the implementation: make the validation composable per
> > service (OVS, nova, etc) and not per role (compute, controller, etc).

+1, now we have composable services we need any validations to be
associated with the services, not the roles.

That said, it's fairly easy to imagine an interface like step_config/config_settings could be used to wire in composable service validations on a per-role basis, e.g similar to what we do here, but


Similar to what was proposed (but never merged) here:


> > 2) Make this information readable and easy to access and understand
> > for our users.
> >
> > I have a proof-of-concept for 1) and partially 2), with the example
> > of
> > OVS: https://review.openstack.org/#/c/342202/
> > This patch will make sure OVS is actually usable at step 4 by
> > running 'ovs-vsctl show' during the Puppet catalog and if it's
> > working, it will create a Puppet anchor. This anchor is currently
> > not useful but could be in future if we want to rely on it for orchestration.
> > I wrote the service validation in Puppet 2 years ago when doing
> > Spinal Stack with eNovance:
> > https://github.com/openstack/puppet-openstacklib/blob/master/manifes
> > ts/service_validation.pp I think we could re-use it very easily, it
> > has been proven to work.
> > Also, the code is within our Puppet profiles, so it's by design
> > composable and we don't need to make any connection with our current
> > services with some magic. Validation will reside within Puppet
> > manifests.
> > If you look my PoC, this code could even live in puppet-vswitch
> > itself (we already have this code for puppet-nova, and some others).

I think having the validations inside the puppet implementation is OK, but ideally I think we do want it to be part of the puppet modules themselves (not part of the puppet-tripleo abstraction layer).

The issue I'd have with putting it in puppet-tripleo is that if we're going to do this in a tripleo specific way, it should probably be done via a method that's more config tool agnostic. Otherwise we'll have to recreate the same validations for future implementations (I'm thinking specifically about containers here, and possibly ansible[1].

So, in summary, I'm +1 on getting this integrated if it can be done with little overhead and it's something we can leverage via the puppet modules vs puppet-tripleo.

> >
> > Ok now, what if validation fails?
> > I'm testing it here: https://review.openstack.org/#/c/342205/
> > If you look at /var/log/messages, you'll see:
> >
> > Error:
> > /Stage[main]/Tripleo::Profile::Base::Neutron::Ovs/Openstacklib::Serv
> > ice_validation[openvswitch]/Exec[execute
> > openvswitch validation]/returns: change from notrun to 0 failed
> >
> > So it's pretty clear by looking at logs that openvswitch service
> > validation failed and something is wrong. You'll also notice in the
> > logs that deployed stopped at step 4 since OVS is not considered to
> > run.
> > It's partially addressing 2) because we need to make it more
> > explicit and readable. Dan Prince had the idea to use
> > https://github.com/ripienaar/puppet-reportprint to print a nice
> > report of Puppet catalog result (we haven't tried it yet). We could
> > also use Operational Tools later to monitor Puppet logs and find
> > Service validation failures.

This all sounds good, but we do need to think beyond the puppet implementation, e.g how will we enable similar validations in a container based deployment?

I remember SpinalStack also used serverspec, can you describe the differences between using that tool (was it only used for post-deploy validation of the whole server, not per-step validation?)

I'm just wondering if the overhead of integrating per-service validations via a more generic tool (not necessarily serverspec but something like it, e.g I've been looking at testinfra which is a more python based tool aiming to do similar things[2]) would be worth it?

Maybe this is complementary to any per-step validation done inside the puppet modules, but we could do something like:

description: Role data for the Heat Engine role.
service_name: heat-api
heat::: foo
step_config: |
include ::tripleo::profile::base::heat::api
group: serverspec
step_4: |
Package "openstack-heat-api"
should be installed
Service "openstack-heat-api"
should be enabled
should be running
Port "8004"
should be listening

Looking at the WIP container composable services patch[3], this can probably be directly reused:

description: Role data for the Keystone API role.
puppet_tags: keystone_config
container_step_config: 1
- '/'
- [ {get_param: DockerNamespace}, {get_param:
DockerKeystoneImage} ]
net: host
privileged: false
restart: always
- /run:/run
- /var/lib/etc-data/json-config/keystone.json:/var/lib/kolla/config_files/keystone.json
group: serverspec
step_1: |
Service "httpd"
should be enabled
should be running
Port "5000"
should be listening
Port "35357"
should be listening

Anyway, just some ideas there - I'm not opposed to what you suggest re the puppet validations, but I'm very aware that we'll be left with a feature gap if we *only* do that, then (pretty soon) enable fully containerized deployments.



[1] http://lists.openstack.org/pipermail/openstack-dev/2016-July/099564.html
[2] https://testinfra.readthedocs.io/en/latest/
[3] https://review.openstack.org/#/c/330659/12/docker/services/keystone.yaml

> >
> >
> > So this email is a bootstrap of discussion, it's open for feedback.
> > Don't take my PoC as something we'll implement. It's an idea and I
> > think it's worth to look at it.
> > I like it for 2 reasons:
> > - the validation code reside within our profiles, so it's composable by design.
> > - it's flexible and allow us to test everything. It can be a bash
> > script, a shell command, a Puppet resource (provider, service, etc).
> >
> > Thanks for reading so far,
> > --
> > Emilien Macchi
> --
> Emilien Macchi
> ______________________________________________________________________
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Steve Hardy
Red Hat Engineering, Cloud

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