Hi, I''m trying to find a formal description of the "Graph based model" that puppet uses but so far I have not been able to find it. Can someone please tell me where to look? Thanks, Thomas Hallgren -- You received this message because you are subscribed to the Google Groups "Puppet Users" group. To post to this group, send email to puppet-users@googlegroups.com. To unsubscribe from this group, send email to puppet-users+unsubscribe@googlegroups.com. For more options, visit this group at http://groups.google.com/group/puppet-users?hl=en.
Hi Thomas,
I don''t know the docs as well as I should: I found a detailed
description of
the process of compiling catalogs.
http://projects.puppetlabs.com/projects/1/wiki/Puppet_Internals
The model in puppet is implemented as a directed acyclic graph (DAG). The
vertices of the graph are resoures, the edges are the relationships (order
dependencies) between resources.
Resource types describe the desired state of a resource in terms of
properties.
ex: File has properties content, mode, owner, group
Types specify the description of a resource, which is abstracted from
providers that specify the implementation (how we query the current state,
how we synchronize)
ex: package { ''foo'': ensure => installed} is a relevant
description
regardless of the implementation of how we query the current state and how
we synchronize if it does not match the description. (could be apt, rpm,
yum)
Properties are attributes of resources that can be synchronized.
The synchronization process is as follows:
- query the real state of the property on the system
- compare to the desired state
- if they are not the same, then synchronize them
- if we have to sync resources, then create an event.
hope this helps!
-Dan
On Tue, Nov 23, 2010 at 5:57 AM, Thomas Hallgren <thomas@tada.se> wrote:
> Hi,
>
> I''m trying to find a formal description of the "Graph based
model"
> that puppet uses but so far I have not been able to find it. Can
> someone please tell me where to look?
>
> Thanks,
> Thomas Hallgren
>
> --
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Thanks Dan. This was very helpful. Regards, Thomas Hallgren -- You received this message because you are subscribed to the Google Groups "Puppet Users" group. To post to this group, send email to puppet-users@googlegroups.com. To unsubscribe from this group, send email to puppet-users+unsubscribe@googlegroups.com. For more options, visit this group at http://groups.google.com/group/puppet-users?hl=en.
Hello, On 11/23/2010 12:34 PM, Dan Bode wrote:> http://projects.puppetlabs.com/projects/1/wiki/Puppet_Internals > > The model in puppet is implemented as a directed acyclic graph (DAG). The > vertices of the graph are resoures, the edges are the relationships (order > dependencies) between resources. > > Resource types describe the desired state of a resource in terms of > properties. > ex: File has properties content, mode, owner, group > > Types specify the description of a resource, which is abstracted from > providers that specify the implementation (how we query the current state, > how we synchronize) > ex: package { ''foo'': ensure => installed} is a relevant description > regardless of the implementation of how we query the current state and how > we synchronize if it does not match the description. (could be apt, rpm, > yum) > > Properties are attributes of resources that can be synchronized. > > The synchronization process is as follows: > - query the real state of the property on the system > - compare to the desired state > - if they are not the same, then synchronize them > - if we have to sync resources, then create an event.This description is actually concise and quite understandable. I would suggest adding it to Puppet''s documentation wiki, not too far away from the "extended knowledge" section [1]. [1]: http://docs.puppetlabs.com/#extended-knowledge -- Gabriel Filion -- You received this message because you are subscribed to the Google Groups "Puppet Users" group. To post to this group, send email to puppet-users@googlegroups.com. To unsubscribe from this group, send email to puppet-users+unsubscribe@googlegroups.com. For more options, visit this group at http://groups.google.com/group/puppet-users?hl=en.
On Wed, Nov 24, 2010 at 10:46 AM, Gabriel Filion <lelutin@gmail.com> wrote:> Hello, > > On 11/23/2010 12:34 PM, Dan Bode wrote: >> http://projects.puppetlabs.com/projects/1/wiki/Puppet_Internals >> >> The model in puppet is implemented as a directed acyclic graph (DAG). The >> vertices of the graph are resoures, the edges are the relationships (order >> dependencies) between resources. >> >> Resource types describe the desired state of a resource in terms of >> properties. >> ex: File has properties content, mode, owner, group >> >> Types specify the description of a resource, which is abstracted from >> providers that specify the implementation (how we query the current state, >> how we synchronize) >> ex: package { ''foo'': ensure => installed} is a relevant description >> regardless of the implementation of how we query the current state and how >> we synchronize if it does not match the description. (could be apt, rpm, >> yum) >> >> Properties are attributes of resources that can be synchronized. >> >> The synchronization process is as follows: >> - query the real state of the property on the system >> - compare to the desired state >> - if they are not the same, then synchronize them >> - if we have to sync resources, then create an event. > > This description is actually concise and quite understandable. I would > suggest adding it to Puppet''s documentation wiki, not too far away from > the "extended knowledge" section [1]. > > [1]: http://docs.puppetlabs.com/#extended-knowledgeJust wanted to point out that we accept patches for the documentation :) I love Dan''s description here, it is indeed concise and understandable. Let''s get it in the docs for sure. -- You received this message because you are subscribed to the Google Groups "Puppet Users" group. To post to this group, send email to puppet-users@googlegroups.com. To unsubscribe from this group, send email to puppet-users+unsubscribe@googlegroups.com. For more options, visit this group at http://groups.google.com/group/puppet-users?hl=en.
Helpful indeed. While reading the description, one thing puzzled me. Is it true that "the required resource will be instantiated after the requiring resource" when building the dependency graph model? I would have expected it to be the other way around... Thanks, Kenn -- You received this message because you are subscribed to the Google Groups "Puppet Users" group. To post to this group, send email to puppet-users@googlegroups.com. To unsubscribe from this group, send email to puppet-users+unsubscribe@googlegroups.com. For more options, visit this group at http://groups.google.com/group/puppet-users?hl=en.