Carts

Carts

Carts are the smallest increment of customization for backend nodes.

Stacki allows the admin to customize the software footprint of a backend node to enable additional functionality.

In a default setup, Stacki installs backend nodes with a very small software footprint. In Stacki parlance, the backend node is brought up to a ping and a prompt.

The backend node will have its network configured, and the SSH daemon is started to allow password-less login access from the frontend.

To make the backend node more useful, other application software and services will need to be installed and configured.

There are several "levels" of installing applications in Stacki. We’re going to look at the simplest case - using a cart to install additional package(s) and starting the associated service.

Assumptions are:

1. The application to be installed is available as an RPM
2. The application can be configured using simple shell command or a script.
3. The developer has a basic knowledge of editing HTML-like syntax.

Stacki uses a collection of XML files that provide the definition of a system, and the instructions for installing a backend node. To extend the software footprint of a node, we will need to extend the XML framework to accommodate the extra functionality required.

The XML structure is not complicated - think of it as HTML with extra tags. The tags Stacki incorporates map to kickstart elements you should already be familiar with: pre, post, main, package, and first boot. From there it's mostly adding shell commands and scripts to install and configure applications.

For more information about the available XML tags, refer to the Stacki Universal XML guide

In Stacki, backend node configuration is controlled by a collection of XML files.

A node XML file contains the description of additional packages and configuration that should be applied to backend hosts.

A node XML file is written in Stacki Universal Language, which is a way to write cart configuration so it applies to multiple OSs.

SUX consists of html tags that map to Linux installation targets: pre, post, main, packages, and first boot.

Seeing how this works is best done through examples. The most common use cases are, adding software, adding files, and adding scripts to configure the software.

Follow these examples to futher customize your cart.

• Adding RPMs
• Adding Files
• Adding Installation Scripts

To understand the difference between Carts and Pallets please see Carts vs. Pallets.