Open Stack

Hello,

I've been reading through the thread and the wiki pages and I'm still
confused by the terms. Is there a clear definition of what do we understand
by component from user's and developer's point of view. If I write
"component, type:MySQL" what is behind that definition? I mean how does the
system know what exactly MySQL is and how to install it? What MySQL version
is it gonna be? Will it be x86 or x64? How does the system understand that
I need MySQL for Windows on Windows VM rather then Linux MySQL? What do I
as a developer need to do so that it would be possible to have "type:
MyCoolComponentType"?


On Tue, Oct 22, 2013 at 8:35 PM, Thomas Spatzier <thomas.spatzier at de.ibm.com
> wrote:

> Zane Bitter <zbitter at redhat.com> wrote on 22.10.2013 17:23:52:
> > From: Zane Bitter <zbitter at redhat.com>
> > To: openstack-dev at lists.openstack.org,
> > Date: 22.10.2013 17:26
> > Subject: Re: [openstack-dev] [Heat] HOT Software configuration proposal
> >
> > On 22/10/13 16:35, Thomas Spatzier wrote:
> > > Zane Bitter <zbitter at redhat.com> wrote on 22.10.2013 15:24:28:
> > >> From: Zane Bitter <zbitter at redhat.com>
> > >> To: openstack-dev at lists.openstack.org,
> > >> Date: 22.10.2013 15:27
> > >> Subject: Re: [openstack-dev] [Heat] HOT Software configuration
> proposal
> > >>
> > >> On 22/10/13 09:15, Thomas Spatzier wrote:
> > >>> BTW, the convention of properties being input and attributes being
> > > output,
> > >>> i.e. that subtle distinction between properties and attributes is not
> > >>> really intuitive, at least not to me as non-native speaker, because I
> > > used
> > >>> to use both words as synonyms.
> > >>
> > >> As a native speaker, I can confidently state that it's not intuitive
> to
> > >> anyone ;)
> > >
> > > Phew, good to read that ;-)
> > >
> > >>
> > >> We unfortunately inherited these names from the Properties section and
> > >> the Fn::GetAtt function in cfn templates. It's even worse than that,
> > >> because there's a whole category of... uh... things (DependsOn,
> > >> DeletionPolicy, &c.) that don't even have a name - I always have to
> > >> resist the urge to call them 'attributes' too.
> > >
> > > So is this something we should try to get straight in HOT while we
> still
> > > have the flexibility?
> >
> > Y-yes. Provided that we can do it without making things *more*
> > confusing, +1. That's hard though, because there are a number of places
> > we have to refer to them, all with different audiences:
> >   - HOT users
> >   - cfn users
> >   - Existing developers
> >   - New developers
> >   - Plugin developers
> >
> > and using different names for the same thing can cause problems. My test
> > for this is: if you were helping a user on IRC debug an issue, is there
> > a high chance you would spend 15 minutes talking past each other because
> > they misunderstand the terminology?
>
> Hm, good point. Seems like it would really cause more confusion than it
> helps. So back away from the general idea of renaming things that exist
> both in cfn and HOT.
> What we should try of course is to give new concepts that will only exist
> in HOT intuitive names.
>
> >
> > > Regarding properties/attributes for example, to me I would call both
> just
> > > properties of a resource or component, and then I can write them or
> read
> > > them like:
> > >
> > > components:
> > >    my_component:
> > >      type: ...
> > >      properties:
> > >        my_prop: { get_property: [ other_component,
> other_component_prop ] }
> > >
> > >    other_component:
> > >      # ...
> > >
> > > I.e. you write property 'my_prop' of 'my_component' in its properties
> > > section, and you read property 'other_component_prop' of
> 'other_component'
> > > using the get_property function.
> > > ... we can also call them attributes, but use one name, not two
> different
> > > names for the same thing.
> >
> > IMO inputs (Properties) and outputs (Fn::GetAtt) are different things
> > (and they exist in different namespaces), so -1 for giving them the same
> > name.
> >
> > In an ideal world I'd like HOT to use something like get_output_data (or
> > maybe just get_data), but OTOH we have e.g. FnGetAtt() and
> > attributes_schema baked in to the plugin API that we can't really
> > change, so it seems likely to lead to developers and users adopting
> > different terminology, or making things very difficult for new
> > developers, or both :(
> >
> > cheers,
> > Zane.
> >
> > _______________________________________________
> > OpenStack-dev mailing list
> > OpenStack-dev at lists.openstack.org
> > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
> >
>
>
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>



-- 
Sincerely yours
Stanislav (Stan) Lagun
Senior Developer
Mirantis
35b/3, Vorontsovskaya St.
Moscow, Russia
Skype: stanlagun
www.mirantis.com
slagun at mirantis.com
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