Using customized product images

The Stackable operator require a certain structure inside the product images, but modifications can be made. This is useful to for example load additional extensions or database drivers into an image.

To deploy a custom image, you will either have to manually load the image into the Kubernetes cluster or you have to deploy it into a custom registry.

Steps

To use a customized image you have to:

  1. Create the customized image using a Stackable base image.

  2. Provide this image into the Kubernetes cluster.

  3. Configure your Stacklet to use the custom image.

Create your customized image

The Stackable operators rely on the structure and contents of the product images, so any modifications need to be done using the Stackable images as base images.

You can find the Stackable Docker images in the Stackable Docker registry. Images follow a naming schema: docker.stackable.tech/stackable/<product>:<product-version>-stackable<stackable-version> where <product> are the products like druid, trino and opa, <product-version> are product versions like 28.0.1, 414 or 0.61.0 and <stackable-version> is a Stackable platform version like 23.7 or 24.3.0. The Stackable version can also be 0.0.0-dev for nightly images. You can use this naming schema together with the Supported product versions list to quickly find the base image you need.

For example, you might use the docker.stackable.tech/stackable/hive:3.1.3-stackable24.3.0 image as a base for a modified Apache Hive image where you add a custom database driver. Use the FROM clause in your Dockerfile to reference the base image.

When tagging the image, there are no requirements by the operator, any registry and tag is possible. To avoid confusion, do not use the Stackable registry for your custom image, as you cannot push the image there. You can also keep the versions in the tag, and simply add a suffix to mark your changes.

For example, for a custom image with a MySQL driver added, you might tag your image with my.corp/stackable/hive:3.1.3-stackable24.3.0-mysql.

Provide the image to the Kubernetes cluster

To deploy containers using this image, the Kubernetes cluster needs to be able to access the image.

You can either upload the image into a custom registry and pull it from there - refer to your registry on how to do this - or make the image available to the Kubernetes cluster directly. For example, in kind you can use the kind load docker-image command to load a local image into the Kind cluster.

Use your customized image in your Stacklet definition

To use the customized image in your Stacklet, adjust the Product image selection section in your Stacklet configuration. Use the custom field to specify your image:

spec:
  image:
    custom: my.corp/stackable/hive:3.1.3-stackable24.3.0-mysql
    productVersion: 3.1.3

Note that you still need to specify the product version was used in the image for the operator to configure it correctly.

With this configuration the operator deploys your Stacklet using your custom image.

Further reading and useful links

  • Read about Product image selection to learn about other ways of specifying a product version or images, for example how to use a custom registry when mirroring Stackable images.

  • Have a look at the Stackable Docker registry to find out which images are available to use as a base.