Overview

The Inventory is a core component of Kapitan: this section aims to explain how it works and how to best take advantage of it.

The Inventory is a hierarchical YAML based structure which you use to capture anything that you want to make available to Kapitan, so that it can be passed on to its templating engines.

The first concept to learn about the Inventory is the target. A target is a file, found under the inventory/targets substructure, that tells Kapitan what you want to compile. It will usually map to something you want to do with Kapitan.

For instance, you might want to define a target for each environment that you want to deploy using Kapitan.

The Inventory lets you also define and reuse common configurations through YAML files that are referred to as classes: by listing classes into target, their content gets merged together and allows you to compose complex configurations without repetitions.

By combining target and classes, the Inventory becomes the SSOT for your whole configuration, and learning how to use it will unleash the real power of Kapitan.

Info

The Kapitan Inventory is based on an open source project called reclass and you can find the full documentation on our Github clone. However we discourage you to look directly at the reclass documentation before you learn more about Kapitan, because Kapitan uses a fork of reclass and greatly simplifies the reclass experience.

Info

Kapitan allows users to switch the inventory backend to reclass-rs. You can switch the backend to reclass-rs by passing --inventory-backend=reclass-rs on the command line. Alternatively, you can define the backend in the .kapitan config file.

See the reclass-rs inventory backend documentation for more details.

Note

Kapitan enforces very little structure for the Inventory, so that you can adapt it to your specific needs: this might be overwhelming at the beginning: don’t worry, we will explain best practice and give guidelines soon.

By default, Kapitan will search for its Inventory under inventory/classes and inventory/targets.

inventory/
├── classes
│   ├── applications
│   ├── components
│   ├── features
│   ├── kapitan
│   ├── projects
│   └── terraform
└── targets
    ├── examples
    ├── kapicorp
    └── terraform