Puppet users - Feb 2010 - using (possibly) undefined out of scope variables in an erb template

I''m trying to use  (possibly) undefined variables that are not in the
scope of my class in an erb template.
How do I combine this :

<% if has_variable?("myvar") then %>
myvar has <%= myvar %> value
<% end %>

with this :
<%= scope.lookupvar(myclass::myvar) %>


The idea is to get the iptables template to go through all the classes
assigned to a machine and add lines on relevant classes only(by
searching for a specific variable in that class),this way I will not
be forced to edit the iptables template/class every time another
module needs to change its iptable settings.

Without checking for undefined variables my code looks like this :

<% classes.each do |current_class| -%>
<% scope.lookupvar(current_class::iptables_input_tags) %>
<% end -%>



Oded


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you might be hitting - http://projects.reductivelabs.com/issues/2309

Ohad

On Thu, Feb 11, 2010 at 1:09 AM, Oded <oded.benozer@gmail.com> wrote:
> I''m trying to use  (possibly) undefined variables that are not in
the
> scope of my class in an erb template.
> How do I combine this :
>
> <% if has_variable?("myvar") then %>
> myvar has <%= myvar %> value
> <% end %>
>
> with this :
> <%= scope.lookupvar(myclass::myvar) %>
>
>
> The idea is to get the iptables template to go through all the classes
> assigned to a machine and add lines on relevant classes only(by
> searching for a specific variable in that class),this way I will not
> be forced to edit the iptables template/class every time another
> module needs to change its iptable settings.
>
> Without checking for undefined variables my code looks like this :
>
> <% classes.each do |current_class| -%>
> <% scope.lookupvar(current_class::iptables_input_tags) %>
> <% end -%>
>
>
>
> Oded
>
>
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>
>
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Actually I am trying to go around it :)
I choose to use the classes array because of the an ordering issue I
encountered while trying to build an array of iptables rules  : the
template would get  evaluated before some  the classes would get the
chance to add lines to the array.
I''m hoping that by using the classes array  (which is in its finale
state before the classes start to run) I can avoid the ordering issue.
my question was about the ruby syntax  of checking for undefined out
of scope variables (or are you trying to tell me that theres no way
around it ?).


Oded



On Feb 11, 10:33 pm, Ohad Levy <ohadl...@gmail.com>
wrote:
> you might be hitting -http://projects.reductivelabs.com/issues/2309
>
> OhadOn Thu, Feb 11, 2010 at 1:09 AM, Oded <oded.beno...@gmail.com>
wrote:
> > I''m trying to use  (possibly) undefined variables that are
not in the
> > scope of my class in an erb template.
> > How do I combine this :
>
> > <% if has_variable?("myvar") then %>
> > myvar has <%= myvar %> value
> > <% end %>
>
> > with this :
> > <%= scope.lookupvar(myclass::myvar) %>
>
> > The idea is to get the iptables template to go through all the classes
> > assigned to a machine and add lines on relevant classes only(by
> > searching for a specific variable in that class),this way I will not
> > be forced to edit the iptables template/class every time another
> > module needs to change its iptable settings.
>
> > Without checking for undefined variables my code looks like this :
>
> > <% classes.each do |current_class| -%>
> > <% scope.lookupvar(current_class::iptables_input_tags) %>
> > <% end -%>
>
> > Oded
>
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Got it !

<% classes.each do |current_class| -%>
<% if has_variable?(current_class + "::iptable_rule_chain") then
-%>
<%= scope.lookupvar(current_class + "::iptable_rule_chain") %>
<% end -%>
<% end -%>

So easy ,all that time I was trying to use Bash style string
concatenation , which for some strange reason didn''t work :)

Now each class that has a variable named "iptable_rule_chain" adds a
line to my template, yey !

Theres a new  issue with scoping now :  if i use this variable in a
class that calls other classes I get duplicate lines as the same
variable is "in the scope"  of several classes ,currently I write the
manifests around this issue (by using "subclasses"),but it would be
nice if I could control the scoping of each variable.
I prefer this solution to using Augeas as it is more
"deterministic" ,  I know exactly how my file will look like without
considering its current  state.


On Feb 13, 8:35 pm, Oded <oded.beno...@gmail.com>
wrote:
> Actually I am trying to go around it :)
> I choose to use the classes array because of the an ordering issue I
> encountered while trying to build an array of iptables rules  : the
> template would get  evaluated before some  the classes would get the
> chance to add lines to the array.
> I''m hoping that by using the classes array  (which is in its
finale
> state before the classes start to run) I can avoid the ordering issue.
> my question was about the ruby syntax  of checking for undefined out
> of scope variables (or are you trying to tell me that theres no way
> around it ?).
>
> Oded
>
> On Feb 11, 10:33 pm, Ohad Levy <ohadl...@gmail.com> wrote:
>
>
>
> > you might be hitting -http://projects.reductivelabs.com/issues/2309
>
> > OhadOn Thu, Feb 11, 2010 at 1:09 AM, Oded
<oded.beno...@gmail.com> wrote:
> > > I''m trying to use  (possibly) undefined variables that
are not in the
> > > scope of my class in an erb template.
> > > How do I combine this :
>
> > > <% if has_variable?("myvar") then %>
> > > myvar has <%= myvar %> value
> > > <% end %>
>
> > > with this :
> > > <%= scope.lookupvar(myclass::myvar) %>
>
> > > The idea is to get the iptables template to go through all the
classes
> > > assigned to a machine and add lines on relevant classes only(by
> > > searching for a specific variable in that class),this way I will
not
> > > be forced to edit the iptables template/class every time another
> > > module needs to change its iptable settings.
>
> > > Without checking for undefined variables my code looks like this
:
>
> > > <% classes.each do |current_class| -%>
> > > <% scope.lookupvar(current_class::iptables_input_tags) %>
> > > <% end -%>
>
> > > Oded
>
> > > --
> > > You received this message because you are subscribed to the
Google Groups
> > > "Puppet Users" group.
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groups.com>
> > > .
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> > >http://groups.google.com/group/puppet-users?hl=en.
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