On 04 Feb 2016, at 14:30, Henrik Lindberg <henrik.lindb...@cloudsmith.com> wrote:
> On 2016-04-02 11:46, Martin Alfke wrote: >> >> On 01 Feb 2016, at 19:15, Henrik Lindberg <henrik.lindb...@cloudsmith.com> >> wrote: >> >>> >>> That is exactly what you should do. An external (file based epp) when >>> called, does not get to see variables in the scope from which it was >>> called/used. This design is deliberate. Think of the template as a function >>> you are calling, and you have to give it its arguments. >> >> In this case the documentation on the website is wrong: >> https://docs.puppetlabs.com/puppet/latest/reference/lang_template_epp.html#example-template >> > The long example is wrong in that it does not show that arguments must be > given in a hash. > > The documetation for epp has unfortunately been boiled down to just the bare > minimum and the important distinction that variables must be given has been > lost in the series of rewrites that were made. > > The implementation clearly restricts epp() to only see global scope. > > The specification is also clear about scoping: > https://github.com/puppetlabs/puppet-specifications/blob/master/language/templates.md#visibility-of-scoped-variables Yes. the written description is clear about that. > > I filed a documentation ticket. > >> The example just switches from template() to epp() function. >> According to your writing you must pass all parameters to the epp() function. >> > > yes, epp() requires that arguments are given in the call. epp() templates > only have access to global variables (i.e. $::osfamily and such). > > >>> >>> Contrast this with the inline_epp, which you can think of as a >>> lambda/code-block. Here the code block gets to see the variables in scope, >>> since it is itself in that scope (part of the same piece of code). >>> >> Got it. >> To be honest: this is ugly. >> I always thought of epp() being a full replacement for template() without >> the scope issue. > > The ERB based template() function is for templates in files. The epp() > function is also for files. The big difference between them is that all > variables used by the template processed by epp() must be given to the > function. > > The inline_epp() may in the special case, when it does not declare parameters > have access to all variables in scope. This was deemed to be harmless as all > of the logic is in one place, and there is never a question of reuse. It is > also seen as an easy way to transition to inline_epp() from inline_template(). > > With that, I am not sure I understand your comments. What is it that you > think is ugly? > >> This especially feels bad, when we will have performance improvement for epp >> in the future. >> > > I have not seen tickets with reports of performance problems. How bad is it? You mentioned it somewhere at PuppetConf that in the future the epp() function will have a performance benefit over template() function due to template() needing the ruby stack whereas epp() is running in the java based parser (as far as I have understood this). > > Best > - henrik > > -- > > Visit my Blog "Puppet on the Edge" > http://puppet-on-the-edge.blogspot.se/ > > -- > You received this message because you are subscribed to the Google Groups > "Puppet Developers" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to puppet-dev+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/puppet-dev/n8vjpn%244u0%241%40ger.gmane.org. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Puppet Developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to puppet-dev+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/puppet-dev/F7162FAD-4521-4CAF-AEA3-B39F87AA4EAD%40gmail.com. For more options, visit https://groups.google.com/d/optout.
