[Pkg-puppet-devel] Bug#605392: Bug#605392: puppet: resource inheritance not working as expected

[Stig Sandbeck Mathisen]

Hendrik Jaeger <hank at leonardo.netwichtig.de> writes:

> As stated in #5349 (http://projects.puppetlabs.com/issues/5349)
> inheritance does not work as expected and not as it used to in
> versions < 2.6.

> I'm not sure about this bugs severity, since it affects only one, but
> a quite important aspect of the description language. I see
> inheritance as one of the features without which puppet is a lot more
> complex to use efficiently.

As far as I can see, it is an implicit dependency cycle that is created
if you attempt to specify a resource dependency in the other direction
as two defined run stages like this.

+-------------+       +-------------+
|   stage 1   |  ---> |   stage 2   |
|             |       |             |
| resource in <-------- resource in |
|   stage 1   |       |   stage 2   |
+-------------+       +-------------+

It is a bug, but a minor one.  It merits a better error message, and a
note in the documentation about not shooting oneself in the foot in this
particular manner.

It should not appear during normal use more than any other dependency
loop, and is quite possible to avoid or fix.  Both the stages and the
resource dependencies are defined by the user, and the error message
says, correctly, that a dependency loop has been created.

It does not, however, say _why_ the dependency loop exists, and that it
is implicit rather than explicit.

> I'd rather see a working 0.25 version in a stable release than 2.6
> with this problem.

I am not sure I agree.  If you keep your 0.25 manifests on 2.6 puppet
master and agents, a dependency loop will not be caused (by this, at
least).

If you introduce run stages in your manifests, you will need to ensure
that your dependencies does not run in the opposite direction of these
implicit dependencies.

-- 
Stig Sandbeck Mathisen
                      ooo, shiny!
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