Hi all, Wonder if it can't "just" (this is not a small task but in terms of design it is small ;)) be a flag on higher level archiver plugins (maven-jar-plugin being the first one we'll all have in mind). I take as a reference jib here which takes into account a creation time for that case ( https://github.com/GoogleContainerTools/jib/blob/master/jib-maven-plugin/src/main/java/com/google/cloud/tools/jib/maven/JibPluginConfiguration.java#L190 ). Long story short, they have ~3 modes:
1. set epoch + 1s (there are issue setting epoch directly) 2. set a constant time configured by the user 3. respect file time (not reproducible but enable to disable it) At the end it means we don't need a project.build.* property but just to enrich plugins (maybe let's start with jar one) to handle that. I also wonder if I'm too biased on the topic but if I would have to work on it now with our current ecosystem, I would "just" (again ;)) use maven-shade-plugin and a set of transformers to handle all files which can have not deterministic changes. This enables to get the feature immediately without anything specific in maven core and handle even external plugin generated files through external transformers - a real reproducible build feature would need this extension anyway, think about frontend resources included in META-INF/resources for example. Only missing piece in shade plugin is the Jar reproducibility handling but this is likely very doable since we already have JarOutputStream impl at apache which can host it IMHO. Romain Manni-Bucau @rmannibucau <https://twitter.com/rmannibucau> | Blog <https://rmannibucau.metawerx.net/> | Old Blog <http://rmannibucau.wordpress.com> | Github <https://github.com/rmannibucau> | LinkedIn <https://www.linkedin.com/in/rmannibucau> | Book <https://www.packtpub.com/application-development/java-ee-8-high-performance> Le dim. 29 sept. 2019 à 17:45, Hervé BOUTEMY <herve.bout...@free.fr> a écrit : > Le dimanche 29 septembre 2019, 12:29:47 CEST Karl Heinz Marbaise a écrit : > > Hi Hervé, > > > > On 29.09.19 11:19, Hervé BOUTEMY wrote: > > > regarding the property name, I had an idea: > > > > > > why not do like we already did for ${project.build.sourceEncoding}, > ie. > > > mimic a future element in pom.xml, in build? > > > > > > could be project.build.timestamp? > > > > This sounds like the best idea... > > > > > > This would mean to define something like this: > > > > <properties> > > <project.build.timestamp>..</project.build.timestamp> > > </properties> > > > > But now there are coming up some questions: > > > > * Is that the real value to be used? > > * Or should it activate the mechanism ? (boolean?) > we can define both a boolean and a timestamp > but the timestamp de-facto means also a boolean: defined means true, > undefined > means false > > > > > <properties> > > <project.build.timestamp.usage>true</project.build.timestamp.usage> > > </properties> > > > > > > * Or should we use it by default and giving the user the opportunity > > to overrite the current timestamp by fixed timestamp for building ? > > This means we would define only the real time to be used during > > building. No need for a kind of activation etc. > > So you could call Maven via: > > > > mvn -Dproject.build.timestamp=... package > > > > > > * Or do we need a combination of the above > > > > First activate, define the format and the timestamp to be used. > > > > > > Furthermore do we need to define a format either which could look like > this: > > > > <properties> > > <project.build.timestamp.usage>true</project.build.timestamp.usage> > > <project.build.timestamp>..</project.build.timestamp> > > > <project.build.timestamp.format>ISO-8601</project.build.timestamp.format> > > </properties> > letting the format as a third parameter is of course feasible, but adds > complexity: is it really necessary? Isn't ISO-8601 sufficient to you? > > > > > > > Kind regards > > Karl Heinz Marbaise > > > > > Le samedi 28 septembre 2019, 17:55:24 CEST Hervé BOUTEMY a écrit : > > >> Achieving Reproducible Builds require only one parameter: plugins that > > >> create zip or tar archives require a fixed timestamp for entries > > >> > > >> Putting that parameter as a pom property with a well known name and > value > > >> format permits to share the configuration between every packaging > plugin. > > >> This also has the advantage that child poms will inherit from parent > > >> value, > > >> and eventually override. > > >> > > >> The question is: *what property name and what value format should we > > >> keep?* > > >> > > >> For the PoC, I chose to extrapolate from a convention from > Reproducible > > >> Builds project, which is very Linux-oriented: SOURCE_DATE_EPOCH > > >> environment > > >> variable, that I transformed into source-date-epoch property name, > > >> keeping > > >> the "date + %s" value > > >> https://reproducible-builds.org/docs/source-date-epoch/ > > >> > > >> > > >> But I feel we can do a more user-readable solution by choosing another > > >> name > > >> and format, like "reproducible-build-timestamp" with an ISO-8601 > combined > > >> date and time representation > > >> > > >> > > >> WDYT? Any other idea? > > >> > > >> Regards, > > >> > > >> Hervé > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@maven.apache.org > For additional commands, e-mail: dev-h...@maven.apache.org > >
