Advanced Variables

Basic variables layering should provides enough flexibility and is generally recommended. This page covers more advanced variables layering.

Advanced Layering Example

Here’s a more complex structure to demonstrate advanced layering.

.kubes/variables
├── base
│   └── deployment.rb
├── base.rb
├── dev.rb
├── prod.rb
└── web
    ├── deployment
    │   ├── dev.rb
    │   └── prod.rb
    └── deployment.rb

Concrete Example

Let’s look at a concrete web/deployment.yaml.

Here are the files that get layered when KUBES_ENV=dev:

.kubes/variables/base.rb
.kubes/variables/dev.rb
.kubes/variables/base/deployment.rb
.kubes/variables/web/deployment.rb
.kubes/variables/web/deployment/dev.rb

And when KUBES_ENV=prod:

.kubes/variables/base.rb
.kubes/variables/prod.rb
.kubes/variables/base/deployment.rb
.kubes/variables/web/deployment.rb
.kubes/variables/web/deployment/prod.rb

With advanced layering you can target a specific role and kind. So variables are only scoped to the resources you want.

App-Level Overrides

If KUBES_APP is set, then app level layer overrides will also be processed. Example:

KUBES_APP=app1 kubes deploy

Here’s an example with some of the additional files that get layered:

.kubes/variables/app1.rb
.kubes/variables/app1/base.rb
.kubes/variables/app1/dev.rb

This is useful if you’re using kubes as part of a central deployer pattern. For the full list of layers refer to the table below:

Full Layering Table

Here’s a table showing the the full layering.

Folder/Pattern	Example
base.rb	base.rb
ENV.rb	dev.rb
base/all.rb	base/all.rb
base/all/ENV.rb	base/all/dev.rb
base/KIND.rb	base/deployment.rb
base/KIND/base.rb	base/deployment/base.rb
base/KIND/ENV.rb	base/deployment/dev.rb
ROLE/KIND.rb	web/deployment.rb
ROLE/KIND/base.rb	web/deployment/base.rb
ROLE/KIND/ENV.rb	web/deployment/dev.rb

If KUBES_APP is set then these additional layers are also processed:

Folder/Pattern	Example
APP.rb	app1.rb
APP/base.rb	app1/base.rb
APP/ENV.rb	app1/dev.rb
APP/base/all.rb	app1/base/all.rb
APP/base/all/ENV.rb	app1/base/all/dev.rb
APP/base/KIND.rb	app1/base/deployment.rb
APP/base/KIND/base.rb	app1/base/deployment/base.rb
APP/base/KIND/ENV.rb	app1/base/deployment/dev.rb
APP/ROLE/KIND.rb	app1/web/deployment.rb
APP/ROLE/KIND/base.rb	app1/web/deployment/base.rb
APP/ROLE/KIND/ENV.rb	app1/web/deployment/dev.rb

Generator

To help you get started quickly, you can generate starter variable code.

$ kubes new variable
      create  .kubes/variables/dev.rb

.kubes/variables/dev.rb

@example = "dev-value"

To create the prod variables, set KUBES_ENV=prod.

$ KUBES_ENV=prod kubes new variable
      create  .kubes/variables/prod.rb

.kubes/variables/prod.rb

@example = "prod-value"

Getting Started