Is there a way to define an ArtifactRepository in a single place and use it everywhere?

Help/Discuss
1

Say I have a functions that creates an ArtifactRepository:

fun RepositoryHandler.myCustomRepository(): MavenArtifactRepository {
    // etc...
}

I want to use this function:

  • for both dependency loading and plugin loading
  • in my root project, all subprojects, and in buildSrc

The best I’ve found is to use settings.gradle.kts and buildSrc/settings.gradle.kts and define and use the function in four places:

  • settings.gradle.kts in pluginManagement
  • settings.gradle.kts in dependencyResolutionManagement
  • buildSrc/settings.gradle.kts in pluginManagement
  • buildSrc/settings.gradle.kts in dependencyResolutionManagement

This still requires that I have 4 copies of this code. Is there some way to define this function in ONE place, and use it in all four of these places?

2

As pluginManagement is executed before settings plugins are the on the class path, even a settings plugin would not help to reduce it to 1.

So the only thing that comes to mind is an init script that could do it, and thus most probably a custom Gradle distribution.

3

I asked this question on Stack Overflow as well, and Simon Jacobs came up with a solution that seems to work.

Here it is with a few more details filled-in:

  1. create a settings plugin in a separate build:
// repositories/build.gradle.kts
plugins {
    `java-gradle-plugin`
    `kotlin-dsl`
}

dependencies {
    repositories {
        gradlePluginPortal()
    }
}

gradlePlugin {
    plugins {
        create("RepositoriesPlugin") {
            id = "my.repositories"
            implementationClass = "RepositoriesPlugin"
        }
    }
}


// repositories/src/main/kotlin/RepositoriesPlugin.kt
class RepositoriesPlugin : Plugin<Settings> {
    override fun apply(target: Settings) {
        target.pluginManagement.repositories.pluginRepositories()
    }
}

fun RepositoryHandler.pluginRepositories() {
    // TODO: set up repositories here
}

fun RepositoryHandler.dependencyRepositories() {
    // TODO: set up repositories here
}
  1. in settings.gradle.kts, in the main build do something like:
pluginManagement {
    includeBuild("repositories")
}

plugins {
    id("my.repositories")
}

dependencyResolutionManagement {
    repositories {
        dependencyRepositories()
    }
}
  1. in settings.gradle.kts, in buildSrc/, do almost the same thing:
pluginManagement {
    includeBuild("repositories")
}

plugins {
    id("my.repositories")
}

dependencyResolutionManagement {
    repositories {
        pluginRepositories()
        dependencyRepositories()
    }
}

Any code we want to share between the 4 repository locations can be in RepositoriesPlugin.kt (once!), so we don’t have to have multiple copies of our repository setup code.

Some caveats:

  1. The pluginManagement.repositories for both builds (main and buildSrc) end up being the same. This is fine for our purposes. I assume a second settings plugin could be defined if these needed to be different.

  2. The repository plugin’s build itself needs repositories set up. :person_facepalming:

    I believe this is only necessary in order to get the Kotlin compiler, so perhaps this could be avoided by writing the plugin in Groovy, but I haven’t tested this.

  3. This is a lot more circuitous than I would have expected for something I’d expect to be a pretty common need, so probably isn’t worth it unless you have sufficiently complex repository setup.