api: establish core v1alpha3 for quickstart

Switch holos to use v1alpha3 so we can establish more of the CUE
structures in the documented API using Go structs.

.cspell.json

@@ -17,6 +17,7 @@
     "clusterissuer",
     "cookiesecret",
     "coredns",
+    "CRD's",
     "crds",
     "creds",
     "crossplane",
@@ -92,6 +93,7 @@
     "Traceid",
     "traefik",
     "uibutton",
+    "untar",
     "Upsert",
     "urandom",
     "usecases",

api/core/v1alpha3/apiobjects.go

@@ -0,0 +1,47 @@
+package v1alpha3
+
+import "google.golang.org/protobuf/types/known/structpb"
+
+// InternalLabel is an arbitrary unique identifier internal to holos itself.
+// The holos cli is expected to never write a InternalLabel value to rendered
+// output files, therefore use a [InternalLabel] when the identifier must be
+// unique and internal.  Defined as a type for clarity and type checking.
+//
+// A InternalLabel is useful to convert a CUE struct to a list, for example
+// producing a list of [APIObject] resources from an [APIObjectMap].  A CUE
+// struct using InternalLabel keys is guaranteed to not lose data when rendering
+// output because a InternalLabel is expected to never be written to the final
+// output.
+type InternalLabel string
+
+// Kind is a kubernetes api object kind. Defined as a type for clarity and type
+// checking.
+type Kind string
+
+// APIObject represents the most basic generic form of a single kubernetes api
+// object.  Represented as a JSON object internally for compatibility between
+// tools, for example loading from CUE.
+type APIObject structpb.Struct
+
+// APIObjectMap represents the marshalled yaml representation of kubernetes api
+// objects.  Do not produce an APIObjectMap directly, instead use [APIObjects]
+// to produce the marshalled yaml representation from CUE data, then provide the
+// result to [Component].
+type APIObjectMap map[Kind]map[InternalLabel]string
+
+// APIObjects represents Kubernetes API objects defined directly from CUE code.
+// Useful to mix in resources to any kind of [Component], for example
+// adding an ExternalSecret resource to a [HelmChart].
+//
+// [Kind] must be the resource kind, e.g. Deployment or Service.
+//
+// [InternalLabel] is an arbitrary internal identifier to uniquely identify the resource
+// within the context of a `holos` command.  Holos will never write the
+// intermediate label to rendered output.
+//
+// Refer to [Component] which accepts an [APIObjectMap] field provided by
+// [APIObjects].
+type APIObjects struct {
+	APIObjects   map[Kind]map[InternalLabel]APIObject `json:"apiObjects"`
+	APIObjectMap APIObjectMap                         `json:"apiObjectMap"`
+}

api/core/v1alpha3/buildplan.go

@@ -0,0 +1,52 @@
+package v1alpha3
+
+// FilePath represents a file path.
+type FilePath string
+
+// FileContent represents file contents.
+type FileContent string
+
+// FileContentMap represents a mapping of file paths to file contents.
+type FileContentMap map[FilePath]FileContent
+
+// BuildPlan represents a build plan for the holos cli to execute.  The purpose
+// of a BuildPlan is to define one or more [Component] kinds.  For example a
+// [HelmChart], [KustomizeBuild], or [KubernetesObjects].
+//
+// A BuildPlan usually has an additional empty [KubernetesObjects] for the
+// purpose of using the [Component] DeployFiles field to deploy an ArgoCD
+// or Flux gitops resource for the holos component.
+type BuildPlan struct {
+	Kind       string        `json:"kind" cue:"\"BuildPlan\""`
+	APIVersion string        `json:"apiVersion" cue:"string | *\"v1alpha3\""`
+	Spec       BuildPlanSpec `json:"spec"`
+}
+
+// BuildPlanSpec represents the specification of the build plan.
+type BuildPlanSpec struct {
+	// Disabled causes the holos cli to take no action over the [BuildPlan].
+	Disabled bool `json:"disabled,omitempty"`
+	// Components represents multiple [HolosComponent] kinds to manage.
+	Components BuildPlanComponents `json:"components,omitempty"`
+}
+
+type BuildPlanComponents struct {
+	Resources             map[InternalLabel]KubernetesObjects `json:"resources,omitempty"`
+	KubernetesObjectsList []KubernetesObjects                 `json:"kubernetesObjectsList,omitempty"`
+	HelmChartList         []HelmChart                         `json:"helmChartList,omitempty"`
+	KustomizeBuildList    []KustomizeBuild                    `json:"kustomizeBuildList,omitempty"`
+}
+
+// Kustomize represents resources necessary to execute a kustomize build.
+// Intended for at least two use cases:
+//
+//  1. Process a [KustomizeBuild] [Component] which represents raw yaml
+//     file resources in a holos component directory.
+//  2. Post process a [HelmChart] [Component] to inject istio, patch jobs,
+//     add custom labels, etc...
+type Kustomize struct {
+	// KustomizeFiles holds file contents for kustomize, e.g. patch files.
+	KustomizeFiles FileContentMap `json:"kustomizeFiles,omitempty"`
+	// ResourcesFile is the file name used for api objects in kustomization.yaml
+	ResourcesFile string `json:"resourcesFile,omitempty"`
+}

api/core/v1alpha3/component.go

@@ -0,0 +1,43 @@
+package v1alpha3
+
+// Component defines the fields common to all holos component kinds.  Every
+// holos component kind should embed Component.
+type Component struct {
+	// Kind is a string value representing the resource this object represents.
+	Kind string `json:"kind"`
+	// APIVersion represents the versioned schema of this representation of an object.
+	APIVersion string `json:"apiVersion" cue:"\"v1alpha3\""`
+	// Metadata represents data about the holos component such as the Name.
+	Metadata Metadata `json:"metadata"`
+
+	// APIObjectMap holds the marshalled representation of api objects.  Useful to
+	// mix in resources to each Component type, for example adding an
+	// ExternalSecret to a [HelmChart] Component.  Refer to [APIObjects].
+	APIObjectMap APIObjectMap `json:"apiObjectMap,omitempty"`
+
+	// DeployFiles represents file paths relative to the cluster deploy directory
+	// with the value representing the file content.  Intended for defining the
+	// ArgoCD Application resource or Flux Kustomization resource from within CUE,
+	// but may be used to render any file related to the build plan from CUE.
+	DeployFiles FileContentMap `json:"deployFiles,omitempty"`
+
+	// Kustomize represents a kubectl kustomize build post-processing step.
+	Kustomize `json:"kustomize,omitempty"`
+
+	// Skip causes holos to take no action regarding this component.
+	Skip bool `json:"skip" cue:"bool | *false"`
+}
+
+// Metadata represents data about the object such as the Name.
+type Metadata struct {
+	// Name represents the name of the holos component.
+	Name string `json:"name"`
+	// Namespace is the primary namespace of the holos component.  A holos
+	// component may manage resources in multiple namespaces, in this case
+	// consider setting the component namespace to default.
+	//
+	// This field is optional because not all resources require a namespace,
+	// particularly CRDs and DeployFiles functionality.
+	// +optional
+	Namespace string `json:"namespace,omitempty"`
+}

api/core/v1alpha3/constants.go

@@ -0,0 +1,11 @@
+package v1alpha3
+
+const (
+	APIVersion    = "v1alpha3"
+	BuildPlanKind = "BuildPlan"
+	HelmChartKind = "HelmChart"
+	// ChartDir is the directory name created in the holos component directory to cache a chart.
+	ChartDir = "vendor"
+	// ResourcesFile is the file name used to store component output when post-processing with kustomize.
+	ResourcesFile = "resources.yaml"
+)

api/core/v1alpha3/doc.go

@@ -0,0 +1,26 @@
+// Package v1alpha3 contains the core API contract between the holos cli and CUE
+// configuration code.  Platform designers, operators, and software developers
+// use this API to write configuration in CUE which `holos` loads.  The overall
+// shape of the API defines imperative actions `holos` should carry out to
+// render the complete yaml that represents a Platform.
+//
+// [Platform] defines the complete configuration of a platform.  With the holos
+// reference platform this takes the shape of one management cluster and at
+// least two workload cluster.  Each cluster has multiple [Component]
+// resources applied to it.
+//
+// Each holos component path, e.g. `components/namespaces` produces exactly one
+// [BuildPlan] which in turn contains a set of [Component] kinds.
+//
+// The primary kinds of [Component] are:
+//
+//  1. [HelmChart] to render config from a helm chart.
+//  2. [KustomizeBuild] to render config from [Kustomize]
+//  3. [KubernetesObjects] to render [APIObjects] defined directly in CUE
+//     configuration.
+//
+// Note that Holos operates as a data pipeline, so the output of a [HelmChart]
+// may be provided to [Kustomize] for post-processing.
+package v1alpha3
+
+//go:generate ../../../hack/gendoc

api/core/v1alpha3/helm.go

@@ -0,0 +1,38 @@
+package v1alpha3
+
+// HelmChart represents a holos component which wraps around an upstream helm
+// chart.  Holos orchestrates helm by providing values obtained from CUE,
+// renders the output using `helm template`, then post-processes the helm output
+// yaml using the general functionality provided by [Component], for
+// example [Kustomize] post-rendering and mixing in additional kubernetes api
+// objects.
+type HelmChart struct {
+	Component `json:",inline"`
+	Kind      string `json:"kind" cue:"\"HelmChart\""`
+
+	// Chart represents a helm chart to manage.
+	Chart Chart `json:"chart"`
+	// ValuesContent represents the values.yaml file holos passes to the `helm
+	// template` command.
+	ValuesContent string `json:"valuesContent"`
+	// EnableHooks enables helm hooks when executing the `helm template` command.
+	EnableHooks bool `json:"enableHooks" cue:"bool | *false"`
+}
+
+// Chart represents a helm chart.
+type Chart struct {
+	// Name represents the chart name.
+	Name string `json:"name"`
+	// Version represents the chart version.
+	Version string `json:"version"`
+	// Release represents the chart release when executing helm template.
+	Release string `json:"release"`
+	// Repository represents the repository to fetch the chart from.
+	Repository Repository `json:"repository,omitempty"`
+}
+
+// Repository represents a helm chart repository.
+type Repository struct {
+	Name string `json:"name"`
+	URL  string `json:"url"`
+}

api/core/v1alpha3/kubernetesobjects.go

@@ -0,0 +1,10 @@
+package v1alpha3
+
+const KubernetesObjectsKind = "KubernetesObjects"
+
+// KubernetesObjects represents a [Component] composed of Kubernetes API
+// objects provided directly from CUE using [APIObjects].
+type KubernetesObjects struct {
+	Component `json:",inline"`
+	Kind      string `json:"kind" cue:"\"KubernetesObjects\""`
+}

api/core/v1alpha3/kustomizebuild.go

@@ -0,0 +1,8 @@
+package v1alpha3
+
+// KustomizeBuild represents a [Component] that renders plain yaml files in
+// the holos component directory using `kubectl kustomize build`.
+type KustomizeBuild struct {
+	Component `json:",inline"`
+	Kind      string `json:"kind" cue:"\"KustomizeBuild\""`
+}

api/core/v1alpha3/platform.go

@@ -0,0 +1,44 @@
+package v1alpha3
+
+import "google.golang.org/protobuf/types/known/structpb"
+
+type PlatformMetadata struct {
+	// Name represents the Platform name.
+	Name string `json:"name"`
+}
+
+// Platform represents a platform to manage.  A Platform resource informs holos
+// which components to build.  The platform resource also acts as a container
+// for the platform model form values provided by the PlatformService.  The
+// primary use case is to collect the cluster names, cluster types, platform
+// model, and holos components to build into one resource.
+type Platform struct {
+	// Kind is a string value representing the resource this object represents.
+	Kind string `json:"kind" cue:"\"Platform\""`
+	// APIVersion represents the versioned schema of this representation of an object.
+	APIVersion string `json:"apiVersion" cue:"string | *\"v1alpha3\""`
+	// Metadata represents data about the object such as the Name.
+	Metadata PlatformMetadata `json:"metadata"`
+
+	// Spec represents the specification.
+	Spec PlatformSpec `json:"spec"`
+}
+
+// PlatformSpec represents the specification of a Platform.  Think of a platform
+// specification as a list of platform components to apply to a list of
+// kubernetes clusters combined with the user-specified Platform Model.
+type PlatformSpec struct {
+	// Model represents the platform model holos gets from from the
+	// PlatformService.GetPlatform rpc method and provides to CUE using a tag.
+	Model structpb.Struct `json:"model"`
+	// Components represents a list of holos components to manage.
+	Components []PlatformSpecComponent `json:"components"`
+}
+
+// PlatformSpecComponent represents a holos component to build or render.
+type PlatformSpecComponent struct {
+	// Path is the path of the component relative to the platform root.
+	Path string `json:"path"`
+	// Cluster is the cluster name to provide when rendering the component.
+	Cluster string `json:"cluster"`
+}