Re: [wildfly-dev] selecting packages from feature-packs

On Oct 21, 2016, at 10:03 AM, Brian Stansberry <brian.stansberry(a)redhat.com&gt; wrote: > On Oct 21, 2016, at 9:20 AM, Alexey Loubyansky <alexey.loubyansky(a)redhat.com&gt; wrote: > > On 10/21/2016 03:50 PM, Brian Stansberry wrote: >> >>> On Oct 19, 2016, at 7:27 AM, Alexey Loubyansky <alexey.loubyansky(a)redhat.com&gt; wrote: >>> >>> Me and Stuart have been thinking about how to express feature-pack >>> package selection in an XML. Each one came up with a proposal but we >>> appear to have slightly different preferences. In case anybody has an >>> opinion or a better suggestion, please, share. >>> >>> Brief description: feature-pack consists of packages. A package is a >>> unit of content. So a set of packages determines the target installation >>> content-wise. Feature-pack has a set of default packages. These are the >>> packages that get installed by default, i.e. when the user installs the >>> feature-pack w/o specifying any package preferences. In addition to the >>> default ones a feature-pack may contains non-default packages, these are >>> present in the feature-pack but will be installed only if the user >>> explicitly asks for them. >>> So, the question is how to express these package preferences in an XML. >>> >>> Proposal 1. >>> >>> - include-default flag (element or attribute) which defaults to true >>> (meaning the default packages will be included by default); >>> >> >> Th “include” element is still supported here, right? So, I can get all the default ones and then use include elements to pull in additional ones. > > Right. > >>> - if include-default is false (meaning nothing is installed by default), >>> then 'include' element can be used to pick the specific packages >>> (default and non-default ones) to be installed; >>> >>> - otherwise (when include-default is true) 'exclude' element can be used >>> to exclude specific undesired default packages. >>> >> >> Can “exclude” be used to exclude dependencies? So I want “a” but not its dependency “b”? If the answer is yes for optional dependencies, what if the dependency isn’t optional? > > Yes, it can be used to exclude dependencies. If a required (non-optional) dependency is excluded, that'll be an error. > >>> Proposal 2. >>> >>> - exclude element - applicable to any package and means do not install >>> the package (and its dependencies); >>> >>> - include element - applicable to non-default packages and means do >>> install the non-default package (and its dependencies); >>> >> What happens if it’s used for a default package? The tool forgives this, right? > > That would be redundant, of course. We could ignore that or issue a warning. That question was kind of a tangent. I asked because I could imagine a case where a package is not default in version 1, so the user adds an “include”. Then in a later version the package is now a default one. You don’t want to break the user for no good reason. > >>> - pick element - applicable to any package and means install only the >>> picked package(s) >> >> and it’s dependencies? If yes, all its dependencies or only non-optional? > > No, the dependencies would have to be picked explicitly. Otherwise, we have to allow exclude and include to be used in combination with pick which will look too confusing. > Ok, then assuming that in Proposal 1 an “include” element always means pull in dependencies, I prefer Proposal 1. Forcing people to list everything just to get a subset of the default packages is painful and will likely break things if the feature-pack adds a new dependency in a later version.

But… There are cases where people do want to explicitly list things and not have unexpected things brought in. See discussion on https://issues.apache.org/jira/browse/MNG-2315 (for which I voted). I do think it’s good to account for that kind of use case. >>> ignoring other default and non-default ones. pick >>> cannot be used in combination with exclude and include. >>> >>> >>> Basically, 'include' and 'exclude' in both proposals are practically the >>> same. The difference is how the picking is expressed. In the first one, >>> everything is explicitly excluded and then the desired ones are >>> explicitly included, in the second one the desired ones are simply >>> explicitly picked. >>> >> >> The answers to my questions on Proposal 1 impact the semantics of include/exclude in different cases, so I’ll defer expressing an opinion for now. :) > > Thanks, > Alexey > >> >>> >>> Thanks, >>> Alexey >>> _______________________________________________ >>> wildfly-dev mailing list >>> wildfly-dev(a)lists.jboss.org >>> https://lists.jboss.org/mailman/listinfo/wildfly-dev -- Brian Stansberry Manager, Senior Principal Software Engineer JBoss by Red Hat _______________________________________________ wildfly-dev mailing list wildfly-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/wildfly-dev