CUEK8s

CUEK8s is an experimental environment for a CUE based approach to Kubernetes manifest management.

It assumes a somewhat homogeneous environment so that abstractions can be provided to service owners, while still provide high levels of customization and flexibility.

The operating environment is assumed to be:

• Multi-tenant (e.g. details, productpage, ratings, reviews)
• Multi-environment (e.g. dev, prod)
• Multi-region (e.g. london, tokyo)
• Multi-cluster (e.g. dev-tokyo-01, dev-tokyo-02)

It is largely incomplete, with some specific offerings being ommitted (either because they are far from complete or too specific to internal use cases. However, it is sufficient as an example and environment to experiment for the purposes of future development.

Packages

Various packages are provided which provide abstraction as well as constrained definitions of Kubernetes resources.

See here for reference documentation.

Kubernetes definitions have also beeen imported which can be used directly if neither the constrained definitions nor the abstractions are appropriate. These definitions are stored under cue.mod/gen/.

Delivery

Resources are grouped together as a unit known as a deliverable.

The reason for this is so that these groups of resources can be deployed as a single unit. It also allows resources to be deployed via different (or even multiple) methods.

Command Line Tool

A command line tool (cuek8s) is provided to interact with configurations.

To build the tool:

make build

and to see available commands and their usage:

./bin/cuek8s help

Local Environment

A CUE tool in the form of tools/bootstrap_tool.cue will spin up a local environment using k3s and k3d.

It can be setup via:

make up

and torn down via:

make down

This creates a minimal environment, with just the dev-tokyo cluster and the following namespaces:

• details-dev
• productpage-dev
• ratings-dev
• reviews-dev

To create a custom environment, the tool can be run via the cue command, and injecting values:

cue [-t environments=ENVIRONMENTS -t regions=REGIONS] up ./tool/...

Similarly, to teardown the custom environment:

cue [-t environments=ENVIRONMENTS -t regions=REGIONS] down ./tool/...

See cue injection for more information about injecting values.