----- Original Message ----- > From: "Corey Osman" <co...@logicminds.biz> > To: "puppet-dev" <puppet-dev@googlegroups.com> > Sent: Saturday, January 30, 2016 7:47:03 PM > Subject: Re: [Puppet-dev] RFC - A specification for module schemas
> On Friday, January 29, 2016 at 10:47:48 PM UTC-8, R.I. Pienaar wrote: >> >> >> >> ----- Original Message ----- >> > From: "Corey Osman" <co...@logicminds.biz <javascript:>> >> > To: "puppet-dev" <puppe...@googlegroups.com <javascript:>> >> > Sent: Saturday, January 30, 2016 5:45:05 AM >> > Subject: [Puppet-dev] RFC - A specification for module schemas >> >> > Hi, >> > >> > I wanted to bring up a conversation in hopes that we as a community can >> create a >> > specification for something I am calling module schemas. Before I get >> into >> > that I want to provide a little background info. >> > >> > This all started a few years ago when hiera first came out. Data >> seperation in >> > the form of parameters and auto hiera lookups quickly became the norm >> and >> > reusable modules exploded into what the forge is today . Because of the >> > popularity of hiera, data validation is now a major problem though. >> Without >> > good data, excellent modules become useless. >> > >> > Puppet 4 and stdlib brought many new functions and ways to validate >> incoming >> > data, and I consider puppet 4 to now be a loosely typed language now. >> Hell, >> > there was even this a long time ago: >> > https://github.com/puppetlabs/puppetlabs-kwalify >> > <https://github.com/puppetlabs/puppetlabs-kwalify> But puppet only >> does so >> > much, and while having validation reside in code might make >> troubleshooting a >> > snap, there is still a delay in the feedback loop when the code is >> tightly >> > coupled with an external “database” of data. Data that is inserted by >> non >> > puppet developers who don’t know YAML or data structures. >> > >> > So with that said I want to introduce something new to puppet module >> > development, called module schemas. A module schema is a specification >> that >> > details the inner workings of a module. For right now this means a >> detailed >> > specification of all the parameters for classes and definitions used >> inside a >> > module who’s goal is to make it impossible to insert a bad data >> structure. But >> > ideally, we can specify so much more (functions, types, providers, >> templates) >> > even hiera calls in weird places like templates and functions, which are >> > usually things that do not get documented and are hard to reference and >> usually >> > requires looking at source code. >> > >> > What does such a schema look like? >> > >> > Here is a example schema for the apache module which contains 446 >> parameters!. >> > >> https://github.com/logicminds/puppet_module_schemas/blob/master/apache_schema.yaml >> >> This in general is something I've wanted for a long time, and I think >> we're almost >> getting for free now in Puppet 4 >> >> In Puppet 4 you can do: >> >> class x(String $y) { } >> >> or >> >> class x(String $y[1,10]) { } >> >> or >> >> class x(Pattern[/\A[a-z].*/]) { } >> >> or >> class x(Enum["stopped", "running"] $y) { } >> >> and many more including very complex matchers. This is a lot more >> featureful AND >> maps 1:1 to the capabilities puppet has natively. >> > > This is one drawback of using an external schema parser, puppet has way > more useful types to check against. Of course Puppet 3 only has the basics > (bool, string, array, hash). I have thought about forking the kwalify > parser and making more data types so it would be more aware of some puppet > data types (absolute path, cert_type, ...). I could go down that route, > but I would probably be the only maintainer. > > > > >> >> I think there are ways now to introspect the classes and extract this >> metadata >> automagically, if not then I think *that* is the feature we should get >> added to >> Puppet and from there build the external validation, introspection and >> testing >> for data as that will give a solution that progresses as Puppet does and >> give a >> lot more "real" results than trying to map this stuff externally to what >> Puppet >> supports >> >> The puppet lookup or similar CLI can be extended to include validation. >> > > While having this built into puppet would be ideal, there are still people > on 2.7, and many more on 3.x so it might take some time to migrate them to > 4.3.x. Not to mention almost all forge modules don't include type checking > in fear that they will discriminate against 3.Xers. (At least thats how I > feel. Internal private modules are a different story. ) > > Having a tool external to puppet means that it is version independent. You > don't have to upgrade to puppet 4.X to get validation. I think this alone > is a very good use case. I also believe there is room for an internal > puppet tool as well which would eventually replace the external tool. > Furthermore, having an external schema also means that when you do upgrade > to puppet 4.x you can map your external schema to puppet data types and > update 3.x code to utilize data types with a tool to retrofit those > additions automatically. > helping people shoot themselves in the foot by using out of date software and soon to be unsupported versions of puppet is a mistake. Look to the future and build for the future. Puppet 4 is VERY VERY different from puppet 3 to the point of being something entirely new. Maintaining backwards support will simply ensure you rapidly become obsolete. What you're proposing is big and important and the data landscape in Puppet has and will continue to change quite rapidly, Puppet 3 compatibility will just mean you end up NOT serving a ever growing user base as people adopt Puppet 4. -- 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/545680893.62.1454225490344.JavaMail.zimbra%40devco.net. For more options, visit https://groups.google.com/d/optout.
