Gradle plugins for working with Docker.

./gradlew build

To publish a new version:

• If bumping Java, then ensure the right version is specified in .github/ files.
• Use git flow to merge it into master.
• Push master and the CI server will publish via ./gradlew publishPlugins.

This plugin simplifies working with Docker images. It is used to build and export images so that they can be packaged into releases.

// file: build.gradle

plugins {
    id 'com.brightsparklabs.gradle.docker-image'
}

The plugin adds the following gradle tasks:

Builds and tags the images as specified in the configuration block.

The following command line arguments can be specified when running this task:

• includeImages: Includes only the specified images in the build. E.g.

    gradle buildDockerImages --includeImages brightsparklabs/alpha,brightsparklabs/bravo
  

• excludeImages: Excludes the specified images from the build. E.g.

    gradle buildDockerImages --excludeImages brightsparklabs/alpha,brightsparklabs/bravo
  

The following tags are automatically added in addition to any specified custom tags:

• latest.
• The version property from the gradle build script.
• The value from running git describe --dirty or 0.0.0-UNKNOWN if there are no git tags.
• The latest git commit id of the folder containing the Dockerfile or UNKNOWN-COMMIT if there is not commit id on the folder (i.e. folder is not checked into git).
• The UTC timestamp of the build in ISO8601 format (without colons).

The following build-args are automatically passed to the docker build command:

• APP_VERSION: the gradle property project.version.
• BUILD_DATE: the UTC timestamp of the build in ISO8601 format.
• VCS_REF: the latest git commit id of the folder containing the Dockerfile.

These build-args can be utilised within the Dockerfile for labels, environment variables, etc:

ARG APP_VERSION
ARG BUILD_DATE
ARG VCS_REF
LABEL org.label-schema.name="docker-gradle" \
      org.label-schema.description="Image used to run gradle-docker" \
      org.label-schema.vendor="brightSPARK Labs" \
      org.label-schema.schema-version="1.0.0-rc1" \
      org.label-schema.vcs-url="https://github.com/brightsparklabs/gradle-docker/" \
      org.label-schema.vcs-ref=${VCS_REF} \
      org.label-schema.build-date=${BUILD_DATE} \
      org.label-schema.version=${APP_VERSION}
ENV META_BUILD_DATE=${BUILD_DATE}
ENV META_VCS_REF=${VCS_REF}
ENV APP_VERSION=${APP_VERSION}

An image tag file will be generated for each Docker image. This file will contain the full tag of the image (based off the version property from the gradle build script). E.g.

• brightsparklabs/alpha:1.0.0

Each image tag file will be named using the format:

• VERSION.DOCKER_IMAGE.<repositoryName>
  • Where:
    • repositoryName is a filename friendly version of the name provided in the plugin's configuration block.

Saves each image to a file which can be loaded by docker load.

Publishes each image to the relevant Docker Registry. The credentials for logging into the Registry must have already been configured via docker login.

Use the following configuration block to configure the plugin:

// file: build.gradle

project.version = 'v1.2.0-RC'

dockerImagePluginConfig {
    // dockerfiles to operate on
    dockerFileDefinitions = [
        [
            'dockerfile' : file('src/alpha/Dockerfile'),
            'name'       : 'brightsparklabs/alpha',
            'tags'       : ['awesome-ant', 'testing']
        ],
        [
            'dockerfile' : file('src/bravo/bravo.Dockerfile'),
            'repository' : 'brightsparklabs/bravo',
            'target'     : 'dev-mode',
            'buildArgs'  : ['--compress', '--quiet'],
            'contextDir' : file('./src')
        ],
    ]
    imagesDir = new File('build/images/')
    imageTagDir = new File('build/imageTags/')
    continueOnFailure = true
    deleteOlderImages = true
    removeDanglingImages = true
    privateDockerServer = 'docker.brightsparklabs.com'
    privateDockerUsername =  project.hasProperty('dockerUsername') ? dockerUsername : System.env.DOCKER_USERNAME
    privateDockerPassword =  project.hasProperty('dockerPassword') ? dockerPassword : System.env.DOCKER_PASSWORD
}

Where:

• dockerFileDefinitions: [Map[]] each map has the following keys:
  • dockerfile: [File] dockerfile to build
  • name: [String] repository name for the built docker image
  • repository: [String] repository name for the built docker image [DEPRECATED use name instead]
  • tags: [String[]`] custom tags for the built docker image [optional]
  • buildArgs: [String[]] additional arguments to the docker build` command [optional]
  • target: [String] target to build (only applies to multi-stage builds) [optional]
• imageTagDir: [File] the directory in which to store images [optional, default: build/images]
• imageTagDir: [File] the directory in which to store image tag files [optional, default: build/imageTags]
• continueOnFailure: [Boolean] set to true if the build should continue even if a docker image build fails [optional, default: false]
• deleteOlderImages: [Boolean] set to true if older images of the same name should be deleted after each new image is built [optional, default: false]
• removeDanglingImages: [Boolean] set to true if the build should remove dangling images after all images are built [optional, default: false]
• privateDockerServer: [String] the private Docker server to log into when building images that use private images as a base [optional]
• privateDockerUsername: [String] the private Docker server username to use when logging into the specified private Docker server [optional]
• privateDockerPassword: [String] the private Docker server password to use when logging into the specified private Docker server [optional]

With the above build.gradle file and a repository structure as follows:

my-project/ (git tag: 1.2.0)
- src/
  - alpha/ (latest commit id: 62d1a77)
    - Dockerfile
  - bravo/ (latest commit id: e8b158f)
    - bravo.Dockerfile

Running gradle saveDockerImages will:

• Build the following docker images:
  • brightsparklabs/alpha:latest
  • brightsparklabs/alpha:v1.2.0-RC (from project.version)
  • brightsparklabs/alpha:1.2.0 (from git repo tag)
  • brightsparklabs/alpha:g62d1a77 (from folder)
  • brightsparklabs/alpha:awesome-ant (custom tag)
  • brightsparklabs/alpha:testing (custom tag)
  • brightsparklabs/bravo:latest
  • brightsparklabs/alpha:v1.2.0-RC (from project.version)
  • brightsparklabs/bravo:1.2.0 (from git repo tag)
  • brightsparklabs/bravo:ge8b158f (from folder)
• Save the image tags to the following files:
  • build/imageTags/VERSION.DOCKER-IMAGE.brightsparklabs-alpha
  • build/imageTags/VERSION.DOCKER-IMAGE.brightsparklabs-bravo
• Create the following docker image files:
  • build/images/docker-image-brightsparklabs-alpha:v1.2.0-RC
  • build/images/docker-image-brightsparklabs-bravo:v1.2.0-RC

Refer to the LICENSE file for details.