DockerSupportFeature

// Adding docker connections on the project level:
project {

    ...

    buildType(DockerBuild)

    features {
        // Docker registry connection at https://docker.io
        dockerRegistry {
            id = "PROJECT_EXT_11"
            name = "Docker Registry"
            url = "https://docker.io" // It is the default, can be omitted
            userName = "user"
            password = "credentialsJSON:******"
        }

        // Amazon Docker ECR registry connection
        dockerECRRegistry {
            id = "PROJECT_EXT_13"
            displayName = "Amazon ECR"
            ecrType = ecrPrivate()

            registryId = "112233"
            regionCode = "us-east-1"

            credentialsType = accessKeys()
            credentialsProvider = accessKey {
                accessKeyId = "AMAZON_KEY_ID"
                secretAccessKey = "credentialsJSON:******"
            }
        }
    }
}

// And now use these 2 connections in the build configuration, as a build feature:
object DockerBuild : BuildType({
    name = "My build with docker connections"

    features {
        dockerSupport {
            loginToRegistry = on {
                dockerRegistryId = "PROJECT_EXT_11,PROJECT_EXT_13"
            }
            cleanupPushedImages = true
        }
    }
})