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<p><font size="2" face="sans-serif">Zane,</font><br>
<font size="2" face="sans-serif"> That would imply that you don't see Heat being used to take actions on some existing resources. Is that correct?<br>
<br>
thanks<br>
-Doug<br>
________________________________________________________<br>
STSM | Standards Architect | IBM Software Group<br>
(919) 254-6905 | IBM 444-6905 | dug@us.ibm.com<br>
The more I'm around some people, the more I like my dog.</font><br>
<br>
<img width="16" height="16" src="cid:1__=0ABBF1CCDF12ED6B8f9e8a93df938@us.ibm.com" border="0" alt="Inactive hide details for Zane Bitter ---05/02/2013 03:49:55 PM---On 01/05/13 22:08, Doug Davis wrote: > I think this conversat"><font size="2" color="#424282" face="sans-serif">Zane Bitter ---05/02/2013 03:49:55 PM---On 01/05/13 22:08, Doug Davis wrote: > I think this conversation is better served by talking about i</font><br>
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<font size="1" color="#5F5F5F" face="sans-serif">From: </font><font size="1" face="sans-serif">Zane Bitter <zbitter@redhat.com></font><br>
<font size="1" color="#5F5F5F" face="sans-serif">To: </font><font size="1" face="sans-serif">openstack-dev@lists.openstack.org, </font><br>
<font size="1" color="#5F5F5F" face="sans-serif">Date: </font><font size="1" face="sans-serif">05/02/2013 03:49 PM</font><br>
<font size="1" color="#5F5F5F" face="sans-serif">Subject: </font><font size="1" face="sans-serif">Re: [openstack-dev] [Nova][Heat] scheduled-images blueprint</font><br>
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<tt><font size="2">On 01/05/13 22:08, Doug Davis wrote:<br>
> I think this conversation is better served by talking about it in a more<br>
> abstract way rather than talking about the specific operation (e.g.<br>
> snapshot) itself - and I think the way Russell described it in an<br>
> earlier note made sense to me. Nova should contain the primitive<br>
> operations of compute. Orchestration around those operations is<br>
> probably best left to something outside of Nova.<br>
><br>
> Now, to some people they may not need anything more complex than "cron"<br>
> to do that orchestration and that's fine. And we shouldn't, and can't,<br>
> stop people from doing that. But, when we talk about a more "official"<br>
> Openstack based solution I think we need to think a bit bigger than "I<br>
> just need to invoke a single Nova API" and realize that people we're<br>
> going to have to handle the more complex usecases (meaning things like<br>
> flows with conditions, etc...). And I think that's where Heat can solve<br>
> the problem very nicely. True, it might be overkill for the one-liner<br>
> problems, but I think those folks will probably be happy with simple<br>
> tools like 'cron'.<br>
><br>
> My concern with trying to put in the solutions for the trivial problems<br>
> directly into Nova is that I'm not clear on where to draw the line. Its<br>
> easy right now to say "single time-based operations go into Nova", but<br>
> how long will it be before that becomes "two commands", and then "3<br>
> commands", oh heck, just make it a script file so it can appear like<br>
> one command. Oh wait, then we can do if-statements! We've now<br>
> recreated Heat :-)<br>
<br>
I think you're misunderstanding what Heat is slightly. It's not a <br>
scripting language, and there are no "if" statements. A Heat template is <br>
a declarative representation of what you'd like your cloud application <br>
to look like, and Heat does the work of transforming that into the <br>
series of API calls to move from the current state to the state declared <br>
in the template.<br>
<br>
What you're talking about is a workflow service, not orchestration. <br>
While orchestration _uses_ a workflow of sorts, they're not the same thing.<br>
<br>
cheers,<br>
Zane.<br>
><br>
> So, circling back around, keep Nova, Glance, etc... as the primitive<br>
> building blocks and let something like Heat be the scripting tool that<br>
> sits on top. This then also puts the burden on Heat to make sure its<br>
> simple enough to use in those trivial usecases (e.g. as easy to use as<br>
> the script file example I mentioned above) but also powerful enough to<br>
> handle the complex ones.<br>
><br>
> thanks<br>
> -Doug<br>
> ________________________________________________________<br>
> STSM | Standards Architect | IBM Software Group<br>
> (919) 254-6905 | IBM 444-6905 | dug@us.ibm.com<br>
> The more I'm around some people, the more I like my dog.<br>
<br>
<br>
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