What is the inventory?

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.

inventory/
├── classes/
│   ├── common/
│   │   └── base.yml        # Foundational configurations
│   ├── components/
│   │   └── web/            # Component-specific settings
│   └── environments/
│       └── production.yml  # Environment-specific configurations
└── targets/
    └── production/
        └── web.yml         # Specific deployment configurations

The Kapitan inventory is divided between targets and classes.

Both classes and targets are yaml file with the same structure

classes:
  - common
  - my.other.class

parameters:
  key: value
  key2:
    subkey: value

Classes are found by default under the inventory/classes directory and define common settings and data that you define once and can be included in other files. This promotes consistency and reduces duplication.

Classes are identified with a name that maps to the directory structure they are nested under. In this example, the kapicorp.common class represented by the file classes/kapicorp/common.yml

# classes/kapicorp/common.yml
classes:
  - common

parameters:
  namespace: ${target_name}
  base_docker_repository: quay.io/kapicorp
  base_domain: kapicorp.com

Targets are found by default under the inventory/targets directory and represent the different environments or components you want to manage. Each target is a YAML file that defines a set of configurations.

For example, you might have targets for production, staging, and development environments.

# targets/production.yml
classes:
  - kapicorp.common
  - components.web
  - environments.production

parameters:
  target_name: web

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.