The Gradle Git Repo Plugin

This plugin allows you to add a git repository as a maven repo, even if the git repository is private, similar to how CocoaPods works.

Using a github repo as a maven repo is a quick and easy way to host maven jars. Private maven repos however, aren't easily accessible via the standard maven http interface, or at least I haven't figured out how to get the authentication right. This plugin simply clones the repo behind the scenes and uses it as a local repo, so if you have permissions to clone the repo you can access it.

This plugin lets you tie access to your repository to github accounts, or any git repository seamlessly. This is most useful if you've already set up to manage distribution this way. Deliver CocoaPods and Maven artifacts with the same system, then sit back and relax.

Building

Run gradle build to build, and gradle publish to publish. Sadly, this plugin no longer uses itself to publish itself :(.

Usage

This plugin needs to be added via the standard plugin mechanism with this buildscript in your top level project

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath group: 'com.layer', name: 'gradle-git-repo-plugin', version: '2.0.2'
    }
}

and then apply the plugin

apply plugin: 'git-repo'

Depending on git repos

This plug adds github and git methods to your repositories block

repositories {
    github("layerhq", "maven-private", "master", "releases")
    git("https://some/clone/url.git", "arbitrary.unique.name", "master", "releases")
}

Add either alongside other repositories and you're good to go. The github variant is just a special case of git, they both do the same thing.

Publishing to github repos

Publishing is a bit less seamless, mostly because there isn't one single way to handle publishing in gradle (also the maven-publish plugin is infuratingly tamper-proof). You're expected to have a task called publish by default, that publishes to the locally cloned repo. That task gets wrapped into a publishToGithub task that handles committing and pushing the change. First, add this configuration block, which will use github by default:

gitPublishConfig{
    org = "layerhq"
    repo = "maven-private"
}

The maven-publish plugin defines a publish task for you, so you just need to supply the right url in the publishing block

publishing {
    publications {
        //...
    }
    repositories {
        maven {
            url "file://${gitPublishConfig.home}/${gitPublishConfig.org}/${gitPublishConfig.repo}/releases"
        }
    }
}

Then you can run

gradle publishToGithub

You can also run

gradle publish

to stage a release in the local github repo and commit it manually.

A version of this with the maven plugin might look like

String url() {
    String org =  gitPublishConfig.org
    String repo = gitPublishConfig.repo
    String repoHome = gitPublishConfig.home
    return "file://$repoHome/$org/$repo/releases"
}

task publishJar(type: Upload, description: "Upload android Jar library") {
    configuration = configurations.sdkJar
    repositories {
        mavenDeployer {
            repository(url: url())
        }
    }
}

Settings

The following gradle properties affect cloning dependencies

offline when defined, no network operations will be performed, the repos will be assumed to be in place
home the base directory for cloning git repos, ~/.gitRepos by default

For publishing, the following configuration is supported, to allow non-github repos and other settings

gitRepoConfig {
	// mandatory

    org = "myorg"
	repo = "myrepo"

	// optional

    gitUrl = "" //used to replace git@${provider}:${org}/${repo}.git
	provider = "github.com" // or "gitlab.com", or any other github like
	branch = "master"
    home = "${System.properties['user.home']}/.gitRepos" base directory for cloning
    publishAndPushTask = "publishToGithub" // the name for the full publish action
    publishTask = "publish" //default publish tasks added by maven-publish plugin
    offline = false // if true, no git clones will be performed, the repo will be assumed to be there
}

Futures

It would be nice to make publishing seamless and completely hide the locally cloned repo. That might require reimplementing maven publishing though. The maven-publish plugin isn't amenable to having its settings messed with after it's been applied unfortunately.

After long-term use, your git repo can get very large, and cloning it becomes slow

Credits

Douglas Rapp

License

The gradle git repo plugin is available under the Apache 2 License. See the LICENSE file for more info.

elovlein/gradle-git-repo-plugin