samples/CUE/kube.cue

package kube

service: [ID=_]: {
	apiVersion: "v1"
	kind:       "Service"
	metadata: {
		name: ID
		labels: {
			app:       ID         // by convention
			domain:    "prod"     // always the same in the given files
			component: #Component // varies per directory
		}
	}
	spec: {
		// Any port has the following properties.
		ports: [...{
			port:     int
			protocol: *"TCP" | "UDP" // from the Kubernetes definition
			name:     string | *"client"
		}]
		selector: metadata.labels // we want those to be the same
	}
}

deployment: [ID=_]: {
	apiVersion: "apps/v1"
	kind:       "Deployment"
	metadata: name: ID
	spec: {
		// 1 is the default, but we allow any number
		replicas: *1 | int
		template: {
			metadata: labels: {
				app:       ID
				domain:    "prod"
				component: #Component
			}
			// we always have one namesake container
			spec: containers: [{name: ID}]
		}
	}
}

#Component: string

daemonSet: [ID=_]: _spec & {
	apiVersion: "apps/v1"
	kind:       "DaemonSet"
	_name:      ID
}

statefulSet: [ID=_]: _spec & {
	apiVersion: "apps/v1"
	kind:       "StatefulSet"
	_name:      ID
}

deployment: [ID=_]: _spec & {
	apiVersion: "apps/v1"
	kind:       "Deployment"
	_name:      ID
	spec: replicas: *1 | int
}

configMap: [ID=_]: {
	metadata: name: ID
	metadata: labels: component: #Component
}

_spec: {
	_name: string

	metadata: name: _name
	metadata: labels: component: #Component
	spec: selector: {}
	spec: template: {
		metadata: labels: {
			app:       _name
			component: #Component
			domain:    "prod"
		}
		spec: containers: [{name: _name}]
	}
}

// Define the _export option and set the default to true
// for all ports defined in all containers.
_spec: spec: template: spec: containers: [...{
	ports: [...{
		_export: *true | false // include the port in the service
	}]
}]

for x in [deployment, daemonSet, statefulSet] for k, v in x {
	service: "\(k)": {
		spec: selector: v.spec.template.metadata.labels

		spec: ports: [
			for c in v.spec.template.spec.containers
			for p in c.ports
			if p._export {
				let Port = p.containerPort // Port is an alias
				port:       *Port | int
				targetPort: *Port | int
			},
		]
	}
}