On Windows - using a resource from a different class

[jmp242]

Not sure - maybe this is a horrible idea, but I've got a package I'm using that would ideally use the same reboot resource as all my other packages, but in this case is in it's own class because there are several steps that are more complicated than just applying the package. On many VMs and test computers, this worked, but on ~7 it fails being unable to find the required resource in the other class. I'm trying to upgrade using chocolatey packages our Autodesk Inventor products:

class inventor {
  require yum, packages

So at the start I require my packages class, so the resource should be defined there (called reboot'before') and seems to be on most computers.

package { 'vc2015':
          ensure   => absent,
          provider => 'chocolatey',
          require  => Reboot['before'],
        }

However, on about 7 computers out of ~80, I get that it can't find the reboot resource. I tried doing Packages::Reboot['before'], but that didn't work either...

Is this even supposed to work? I'm using Puppet Agent 1.8.1 on the client, which is Windows 7 x64 SP1. Chocolatey 10.2 for business but this seems a straight puppet resource / syntax error for me.

[jcbollinger]

On Tuesday, May 9, 2017 at 7:31:30 AM UTC-5, jmp242 wrote:

Not sure - maybe this is a horrible idea, but I've got a package I'm using that would ideally use the same reboot resource as all my other packages, but in this case is in it's own class because there are several steps that are more complicated than just applying the package. On many VMs and test computers, this worked, but on ~7 it fails being unable to find the required resource in the other class. I'm trying to upgrade using chocolatey packages our Autodesk Inventor products:

class inventor {
  require yum, packages

So at the start I require my packages class, so the resource should be defined there (called reboot'before') and seems to be on most computers.

package { 'vc2015':
          ensure   => absent,
          provider => 'chocolatey',
          require  => Reboot['before'],
        }

However, on about 7 computers out of ~80, I get that it can't find the reboot resource. I tried doing Packages::Reboot['before'], but that didn't work either...

Resources are global once declared.  If the form you present works for some machines but not for others, therefore, it seems logical to conclude that the wanted resource is not declared on the systems where it fails.

And indeed, the points out a serious flaw in your approach: if you depend directly on a resource declared (or expected to be declared) by a different class, then you implicitly depend on that class being declared.  If, as in this case, you do not also place an explicit dependency on that, then you are at risk of that dependency not being met.  On the other hand, if you do place the explicit dependency (e.g. by include-ing or require-ing the class) then you are probably better off expressing the ordering relationship in terms of the class, not the resources it declares.

I note in passing, however, that there is another, separate, potential problem here: the correct name for the resource type for use in a resource reference.  The fully-qualified name should always be used, but since there is no Reboot among the resource types included with core Puppet, I'm uncertain what the fully-qualified name would be in this case.  If it is a native type then its name is in the anonymous namespace.  If it is a defined type, then its fully-qualified name depends on how it was declared, but it should have been declared in a module, with its name assigned to the module's namespace.  In any event, which class declares a particular resource instance has nothing whatever to do with how that instance can be referenced.
 

Is this even supposed to work? I'm using Puppet Agent 1.8.1 on the client, which is Windows 7 x64 SP1. Chocolatey 10.2 for business but this seems a straight puppet resource / syntax error for me.

It can work, but it would be better to create a class whose only job is to ensure that the machine is rebooted, and for every other class that conceives a need to reboot to (1) declare that class (using one of the include-like forms) and (2) establish an appropriate ordering relationship with the class.  It is better for classes to avoid dependencies on the internals of other classes; if you do it at all, you should at least avoid doing it across module boundaries.


John

[jcbollinger]

On Thursday, May 11, 2017 at 9:51:09 AM UTC-5, jcbollinger wrote:

[...]  If, as in this case, you do not also place an explicit dependency on that, then you are at risk of that dependency not being met.

Correction: it appears that perhaps you do place such a dependency by require-ing class "packages", or at least that you intend to do.  If that class directly or indirectly is responsible for declaring Reboot['before'] then I conclude that either it is not doing its job or that your problem falls in the resource-naming category I described second.  If it directly or indirectly contains that resource (a different consideration), then no direct relationship is required between that resource and any resource declared in class 'inventor'.  In that case, you might solve the problem by removing the 'require' attribute from Package['vc2015'].  This would result in a form close to the one I recommended, with the difference being that class 'packages' presumably has more responsibilities than just ensuring that the machine reboots.

John