k8s-cuelang

Testing CUE (cuelang) with K8s manifests

Project dependencies (MacOS)

Please keep in mind that this POC was written on a MacOS machine and is therefore untested on other OSes.

At a bare minimum, you need the cue binary. If you want to run the tests you also needs bats, kubeval and conftest. On MacOS:

    ❯ brew install cuelang/tap/cue
    ❯ brew install bats-core
    ❯ brew tap instrumenta/instrumenta
    ❯ brew install confest # Instrumenta tap
    ❯ brew install kubeval # Same thing

CUE -> YAML

• Based on the CUE Kubernetes tutorial
• One kube.cue per domain directory to fill the namespace of K8s resources
  • See backend/kube.cue
• One kube.cue per microservice directory to describe its configuration
  • See backend/{awesome-service,cool-service}/kube.cue

Evaluating the CUE files to generate YAML manifests

You can dump the service configuration by using the cue_dump.sh script. Examples:

    ❯ bash cue_dump.sh backend cool-service # For cool-service
    ❯ bash cue_dump.sh backend awesome-service # For awesome-service

Running the tests

Take a look at the tests to see how to integrate unit tests and policy validation.

Run the tests with the tests.sh script.

    ❯ bash tests.sh