[PROPOSAL] Locations and CM tools

[Hadrian Zbarcea]

Hi,

Over the Thanksgiving weekend I spend a lot of time looking at Salt and 
Ansible. I used the Chef and old Salt support as a starting point and 
got to things somewhat working, but not in a way that satisfied me. I 
got back to the concept of Location that caused my problems in the past 
and I knew I'll have to look more into. Yesterday I had a short chat 
with Cipi@ and he threw a very interesting idea that got me thinking all 
day. There are 2 proposals coming out of it, this being the first.

Brooklyn is not really a CM tool, although sometimes it's perceive as 
such because of its advertised features (I do get the "oh, but I could 
do this with <my cm tool of choice> already" answer many a time). 
Brooklyn could (and should) use such a CM tool under the hood. Brooklyn 
is more concerned with the "what" (via blueprints) not the "how". As 
such, unless I am mistaken, there is no concept of Package Manager, or 
Location where deployment is governed by a Package Manager. (The closest 
we got is BashCommands.installPackage(...) flavors and helpers like 
BashCommands.if<Cond>Else0/1.

I believe a better model would be to have something like ChefLocation, 
SaltLocation, AnsibleLocation, etc. layered on top of another 
MachineProvisioningLocation (which could be elastic or not). Note that 
multiple such ConfigurationManagementLocations (of the same or different 
kind) could coexist layered on top of MachineProvisioningLocation (such 
as a public cloud or byon). One or more machines at such a location 
would be designated as "master", managing the other Locations at that 
location.

The architectural rationale (imo) for such a model is that CM tools 
actually manage machines (Locations) and not services directly.

Related to this I think a PackageManager (and maybe a 
PackageManagedLocation) may be necessary. The same box could use yum 
(Centos et al) and npm, or pip, or gems to manage packages and they 
could all coexist on the same box. This starts to move on the CM tools 
turf, but I feel it's needed.

Thoughts?
Hadrian