Building guest images

Sahara plugins represent different Hadoop or other Big Data platforms and requires specific guest images.

While it is possible to use cloud images which only contain the basic software requirements (also called plain images), their usage slows down the cluster provisioning process and was not throughly tested recently.

It is strongly advised to build images which contain the software required to create the clusters for the various plugins and use them instead of plain images.

Sahara currently provides two different tools for building guest images: - sahara-image-pack is newer and support more recent images; - sahara-image-create is the older tool.

Both tools are described in the details in the next sections.

The documentation of each plugin describes which method is supported for the various versions. If both are supported, sahara-image-pack is recommended.

General requirements for guest images

There are few common requirements for all guest images, which must be based on GNU/Linux distributions.

  • cloud-init must be installed

  • the ssh server must be installed

  • the firewall, if enabled, must allow connections on port 22 (ssh)

The cloud images provided by the GNU/Linux distributions respect those requirements.

Each plugin specifies additional requirements. The image building tools provided by Sahara take care of preparing the images with those additional requirements.