elasticsearch/qa/build.gradle

import org.elasticsearch.gradle.test.RestIntegTestTask
import org.elasticsearch.gradle.testclusters.TestClustersPlugin

subprojects { Project subproj ->
  subproj.tasks.withType(RestIntegTestTask).configureEach {
    if (subproj.extensions.findByName("${it.name}Cluster")) {
      subproj.extensions.configure("${it.name}Cluster") { cluster ->
        cluster.distribution = System.getProperty('tests.distribution', 'oss')
      }
    }
  }
  plugins.withType(TestClustersPlugin).whenPluginAdded {
    testClusters.all {
      testDistribution = System.getProperty('tests.distribution', 'oss').toUpperCase()
    }
  }
}