kapitan_overview.md

Main concepts

Inventory

Inventory is a hierarchical database of variables, defined in yaml files, that are passed to the targets during compilation. This will be explained in detail in the inventory section of the documentation.

Components (templates)

Components will receive the inventory values for each individual target and gets rendered and saved into the compiled directory. The types of available templates and how to use them is discussed in the compile operation section of the documentation.

Typical Folder Structure

kapitan init

To start off a kapitan project, you can run kapitan init --directory <directory> to populate a new directory with the recommended kapitan folder structure.

The bare minimum structure that makes use of kapitan features may look as follows:

.
├── components
│   ├── mycomponent.jsonnet
├── templates
├── ├── README.md
├── inventory
│   ├── classes
│   │   ├── common.yml
│   └── targets
│       ├── dev.yml
│       ├── staging.yml
│       └── prod.yml
├── refs
│   ├── targets
│   │   ├── prod
│   │   │   └── password
└───├── common
        └── example-com-tls.key

• components: stores jsonnet files each of which corresponds to an application (for example)
• templates: stores Jinja2 and Kadet templates
• inventory/targets: stores target files
• inventory/classes: stores inventory values to be inherited by targets
• refs: stores secrets referenced inside the inventory

Example: kubernetes deployment

Refer to the structure below for more production-like uses of kapitan for kubernetes deployment:

.
├── components
│   ├── elasticsearch
│   │   ├── configmap.jsonnet
│   │   ├── deployment.jsonnet
│   │   ├── main.jsonnet
│   │   └── service.jsonnet
│   └── nginx
│       ├── configmap.jsonnet
│       ├── deployment.jsonnet
│       ├── main.jsonnet
│       ├── nginx.conf.j2
│       └── service.jsonnet
├── inventory
│   ├── classes
│   │   ├── cluster
│   │   │   ├── cluster1.yml
│   │   │   └── cluster2.yml
│   │   ├── component
│   │   │   ├── elasticsearch.yml
│   │   │   ├── nginx.yml
│   │   │   └── zookeeper.yml
│   │   └── environment
│   │       ├── dev.yml
│   │       └── prod.yml
│   └── targets
│       ├── dev-cluster1-elasticsearch.yml
│       ├── prod-cluster1-elasticsearch.yml
│       └── prod-cluster2-frontend.yml
├── refs
│   ├── targets
│   │   ├── prod-cluster1-elasticsearch
│   │   │   └── password
│   ├── common
│   │   └── example-com-tls.key
├── lib
    ├── kapitan.libjsonnet
    └── kube.libjsonnet

The use of each file in this folder will become clear in the the subsequent documentations.