Open Stack

Excerpts from Joshua Harlow's message of 2016-06-07 08:46:28 -0700:
> Clint Byrum wrote:
> > Excerpts from Kris G. Lindgren's message of 2016-06-06 20:44:26 +0000:
> >> Hi ironic folks,
> >> As I'm trying to explore how GoDaddy can use ironic I've created the following in an attempt to document some of my concerns, and I'm wondering if you folks could help myself identity ongoing work to solve these (or alternatives?)
> >
> > Hi Kris. I've been using Ironic in various forms for a while, and I can
> > answer a few of these things.
> >
> >> List of concerns with ironic:
> >>
> >> 1.)Nova<->  ironic interactions are generally seem terrible?
> >
> > I don't know if I'd call it terrible, but there's friction. Things that
> > are unchangable on hardware are just software configs in vms (like mac
> > addresses, overlays, etc), and things that make no sense in VMs are
> > pretty standard on servers (trunked vlans, bonding, etc).
> >
> > One way we've gotten around it is by using Ironic standalone via
> > Bifrost[1]. This deploys Ironic in wide open auth mode on 127.0.0.1,
> > and includes playbooks to build config drives and deploy images in a
> > fairly rudimentary way without Nova.
> >
> > I call this the "better than Cobbler" way of getting a toe into the
> > Ironic waters.
> >
> > [1] https://github.com/openstack/bifrost
> 
> Out of curiosity, why ansible vs turning 
> https://github.com/openstack/nova/blob/master/nova/virt/ironic/driver.py 
> (or something like it) into a tiny-wsgi-app (pick useful name here) that 
> has its own REST api (that looks pretty similar to the public functions 
> in that driver file)?

That's an interesting idea. I think a reason Bifrost doesn't just import
nova virt drivers is that they're likely _not_ a supported public API
(despite not having _'s at the front). Also, a lot of the reason Bifrost
exists is to enable users to get the benefits of all the baremetal
abstraction work done in Ironic without having to fully embrace all of
OpenStack's core. So while you could get a little bit of the stuff from
nova (like config drive building), you'd still need to handle network
address assignment, image management, etc. etc., and pretty soon you
start having to run a tiny glance and a tiny neutron. The Bifrost way
is the opposite: I just want a tiny Ironic, and _nothing_ else.

> 
> That seems almost easier than building a bunch of ansible scripts that 
> appear (at a glance) to do similar things; and u get the benefit of 
> using a actual programming language vs a 
> half-programming-ansible-yaml-language...
> 
> A realization I'm having is that I'm really not a fan of using ansible 
> as a half-programming-ansible-yaml-language, which it seems like people 
> start to try to do after a while (because at some point you need 
> something like if statements, then things like [1] get created), no 
> offense to the authors, but I guess this is my personal preference (it's 
> also one of the reasons taskflow directly is a lib. in python, because 
> <meh>, people don't need to learn a new language).
> 

We use python in Ansible all the time:

http://git.openstack.org/cgit/openstack/bifrost/tree/playbooks/library

The reason to use Ansible is that it has already implemented all of
the idempotency and error handling and UI needs that one might need for
running workflows.

I've tried multiple times to understand taskflow, and to me, Ansible is
the anti-taskflow. It's easy to pick up, easy to read the workflows,
doesn't require deep surgery on your code to use (just execute
ansible-playbook), and is full of modules to support nearly anything
your deployment may need.