Jira (PUP-1963) Resources type and metaparameters don't seem to work, specifically notify.

[Charlie Sharpsteen (JIRA)]

Title: Message Title

Charlie Sharpsteen commented on an issue   Re: Resources type and metaparameters don't seem to work, specifically notify. Alright. This is an interesting one, that eventually led into the Transaction where the agent evaluates a catalog received from the master. The investigation turned up some strange behavior, so this update will be a bit detailed. Catalogs and Edges Relationships between Puppet resources are tracked in two separate places. The main catalog tracks "containment edges" which represent the hierarchical structure of the node, classes, defined types and the individual resources inside each of those structures. The main catalog also has an instance variable called relationship_graph that keeps track of "dependency edges" which are relationships defined by meta-parameters such as require, notify, etc. The important thing to note is that the relationship_graph, and associated dependency edges, is built lazily the first time it is referenced by the main catalog. Generated Resources In certain cases, resource definitions are generated and added to the catalog during the agent run instead of during compilation on the master. Use of the Resources type is one of these cases. The Resources type needs to generate new resource instances for things it finds on the agent so that it can purge instances that are not managed by the catalog. The important thing to note is that for generated resources, edged created by Notify and Subscribe metaparameters are never explicitly added to the relationship_graph. The Problem Generated resources are created after the relationship_graph is built. This means Subscribe or Notify parameters attached to those resources are never added to the relationship_graph. So, no event is ever generated for something like: resources { [ "foo", "bar"]: purge => true, notify => Service["baz"] } A secondary issue pops up in Puppet versions prior to 3.3.0 which refactored a lot of code to enable manifest-ordered application of resources. Prior to 3.3.0, the very first generated resource would be included in relationship_graph because the genesis of this first resource would cause the graph to be built. This leads to the warnings reflected in the linked Redmine ticket: warning: /Mailalias[bin]: Whit[Completed_class[Postfix]],Whit[Completed_stage[main]],Exec[newaliases] still depend on me -- not purging Purge seems to have a different idea of what resource dependencies mean compared to the rest of the Puppet codebase. Purge seems to think that a dependency relationship means "the resource must exist" instead of "the resource must be synched first" and thus refuses to destroy things. Purge has acted this way since it sprang into existance. A Possible Solution Two changes: Ensure metaprameters such as Notify and Subscribe are fully evaluated for generated resources and added to the relationship_graph. Allow resources to be purged even whey they have dependency relationships. Not doing so seems inconsistent with how the rest of Puppet operates. Change 2 seems like a breaking change that could only go out in Puppet 4.x. However, since dependencies are not properly generated in the first palace there may not be any existing behavior to break. Add Comment   Puppet / PUP-1963 Resources type and metaparameters don't seem to work, specifically notify. First off I will quickly explain what it is I'm trying to do. I have installed the puppetlabs-apache-0.0.3 module that provides a new type called a2mod. My goal is to use virtual resources to collect a list of modules to enable/disable on a node. I would also however, like to ensure that all other apache modules are disabled on the system. I found the... This message was sent by Atlassian JIRA (v6.1.4#6159-sha1:44eaede) -- You received this message because you are subscribed to the Google Groups "Puppet Bugs" group. To unsubscribe from this group and stop receiving emails from it, send an email to puppet-bugs+unsubscr...@googlegroups.com. To post to this group, send email to puppet-bugs@googlegroups.com. Visit this group at http://groups.google.com/group/puppet-bugs. For more options, visit https://groups.google.com/d/optout.