Components

Nyl components are effectively templates that you can instantiate them similar to standard Kubernetes resources. They are treated in a way similar to CRDs, only that they will never to pushed to the Kubernetes API server and instead be replaced throuhg a first reconcilation phase during nyl template.

Components are built on top of Helm chart inlining.

How Nyl looks for components

Nyl by default looks for components in a components/ directory relative to your nyl-project.ext (or relative to your current working directory if there is no nyl-project.<ext>). You can also override the path where Nyl looks in the nyl-project.<ext>:

TOMLYAMLJSON

nyl-project.toml

[settings]
components_path = "../../components"

nyl-project.yaml

settings:
  components_path: ../../components

nyl-project.json

{
    "settings": {
        "components_path": "../../components"
    }
}

Component directory structure

A component must exist in a directory relative to the components_path in a path formatted as {apiVersion}/{kind}. Hence, a typical project structure could look like this:

/
    components/
        example.org/
            v1/
                MyComponent/
                    [component definition]
    nyl-project.yaml
    myapp.yaml

The [component definition] must be a type of component Nyl understands. Currently, it only supports Helm charts.

Using components

In your application manifests, you can instantiate a component by declaring it similar to a standard Kubernetes resource. Nyl will try to lookup if that component exists and then instantiate it, or otherwise leave the resource untouched.

myapp.yaml

apiVersion: example.org/v1
kind: MyComponent
metadata:
    name: mycomponent
spec:
    key: value

Component resource metadata

The component's metadata field will be passed to the Helm values. This allows forwarding annotations and labels, if any.

Tips & tricks

You can use nyl new component example.org/v1 MyComponent to create the boilerplate for a new Nyl component. Currently this is synonymous to calling nyl new chart {components_path}/example.org/v1/MyComponent.