feat: Combine generic variables with provider specific variables

1. Combine generic variables with provider specific variables, leading to a
   single variable per provider. This will be provided by a separate discover
   variables hook per provider that will have to be referenced by name in the
   clusterclass.
2. The name of this single variable will always be clusterConfig regardless of
   provider, but 1 will ensure that this variable has only the relevant fields
   for the cluster provider. Having the same variable name gives a consistent
   feel across providers.
3. Remove registration of individual patches and only keep meta patches. This
   simplifies things. We keep the implementations separate for better
   testability and also to allow for inclusion in other libraries.

Author: jimmidyson

api/v1alpha1/aws_clusterconfig_types.go

@@ -4,6 +4,8 @@
 package v1alpha1
 
 import (
+	"maps"
+
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
 
@@ -24,17 +26,26 @@ type AWSClusterConfig struct {
 type AWSClusterConfigSpec struct {
 	// +optional
 	Region *Region `json:"region,omitempty"`
+
+	GenericClusterConfig `json:",inline"`
 }
 
 func (AWSClusterConfigSpec) VariableSchema() clusterv1.VariableSchema {
+	clusterConfigProps := GenericClusterConfig{}.VariableSchema().OpenAPIV3Schema.Properties
+
+	maps.Copy(
+		clusterConfigProps,
+		map[string]clusterv1.JSONSchemaProps{
+			"region": Region("").VariableSchema().OpenAPIV3Schema,
+		},
+	)
+
 	return clusterv1.VariableSchema{
 		OpenAPIV3Schema: clusterv1.JSONSchemaProps{
-			Description: "AWS Cluster configuration",
+			Description: "AWS cluster configuration",
 			Type:        "object",
-			Properties: map[string]clusterv1.JSONSchemaProps{
-				"region": Region("").VariableSchema().OpenAPIV3Schema,
-			},
-			Required: []string{"region"},
+			Properties:  clusterConfigProps,
+			Required:    []string{"region"},
 		},
 	}
 }

api/v1alpha1/clusterconfig_types.go

@@ -4,7 +4,6 @@
 package v1alpha1
 
 import (
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
 
 	"github.com/d2iq-labs/capi-runtime-extensions/common/pkg/capi/clustertopology/variables"
@@ -15,18 +14,8 @@ const (
 	CNIProviderCalico = "calico"
 )
 
-//+kubebuilder:object:root=true
-
-// ClusterConfig is the Schema for the clusterconfigs API.
-type ClusterConfig struct {
-	metav1.TypeMeta   `json:",inline"`
-	metav1.ObjectMeta `json:"metadata,omitempty"`
-
-	Spec ClusterConfigSpec `json:"spec,omitempty"`
-}
-
-// ClusterConfigSpec defines the desired state of ClusterConfig.
-type ClusterConfigSpec struct {
+// GenericClusterConfig defines the generic cluster configdesired.
+type GenericClusterConfig struct {
 	// +optional
 	KubernetesImageRepository *KubernetesImageRepository `json:"kubernetesImageRepository,omitempty"`
 
@@ -43,7 +32,7 @@ type ClusterConfigSpec struct {
 	Addons *Addons `json:"addons,omitempty"`
 }
 
-func (ClusterConfigSpec) VariableSchema() clusterv1.VariableSchema {
+func (GenericClusterConfig) VariableSchema() clusterv1.VariableSchema {
 	return clusterv1.VariableSchema{
 		OpenAPIV3Schema: clusterv1.JSONSchemaProps{
 			Description: "Cluster configuration",
@@ -240,8 +229,3 @@ func (NFD) VariableSchema() clusterv1.VariableSchema {
 		},
 	}
 }
-
-// +kubebuilder:object:root=true
-func init() {
-	SchemeBuilder.Register(&ClusterConfig{})
-}

api/v1alpha1/docker_clusterconfig_types.go

@@ -0,0 +1,40 @@
+// Copyright 2023 D2iQ, Inc. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package v1alpha1
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
+)
+
+//+kubebuilder:object:root=true
+
+// DockerClusterConfig is the Schema for the dockerclusterconfigs API.
+type DockerClusterConfig struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	Spec AWSClusterConfigSpec `json:"spec,omitempty"`
+}
+
+// DockerClusterConfigSpec defines the desired state of DockerClusterConfig.
+type DockerClusterConfigSpec struct {
+	GenericClusterConfig `json:",inline"`
+}
+
+func (DockerClusterConfigSpec) VariableSchema() clusterv1.VariableSchema {
+	clusterConfigProps := GenericClusterConfig{}.VariableSchema().OpenAPIV3Schema.Properties
+
+	return clusterv1.VariableSchema{
+		OpenAPIV3Schema: clusterv1.JSONSchemaProps{
+			Description: "Docker cluster configuration",
+			Type:        "object",
+			Properties:  clusterConfigProps,
+		},
+	}
+}
+
+func init() {
+	SchemeBuilder.Register(&DockerClusterConfig{})
+}

api/v1alpha1/zz_generated.deepcopy.go

@@ -29,7 +29,7 @@ import (
 	"github.com/d2iq-labs/capi-runtime-extensions/common/pkg/server"
 	awsclusterconfig "github.com/d2iq-labs/capi-runtime-extensions/pkg/handlers/aws/clusterconfig"
 	"github.com/d2iq-labs/capi-runtime-extensions/pkg/handlers/aws/mutation/region"
-	genericclusterconfig "github.com/d2iq-labs/capi-runtime-extensions/pkg/handlers/generic/clusterconfig"
+	dockerclusterconfig "github.com/d2iq-labs/capi-runtime-extensions/pkg/handlers/docker/clusterconfig"
 	"github.com/d2iq-labs/capi-runtime-extensions/pkg/handlers/generic/lifecycle/cni/calico"
 	"github.com/d2iq-labs/capi-runtime-extensions/pkg/handlers/generic/lifecycle/nfd"
 	"github.com/d2iq-labs/capi-runtime-extensions/pkg/handlers/generic/lifecycle/servicelbgc"
@@ -119,60 +119,49 @@ func main() {
 	}
 
 	// Handlers for lifecycle hooks.
-	genericLifeCycleHandlers := []handlers.Named{
+	genericLifecycleHandlers := []handlers.Named{
+		calico.New(mgr.GetClient(), calicoCNIConfig),
+		nfd.New(mgr.GetClient(), nfdConfig),
 		servicelbgc.New(mgr.GetClient()),
 	}
-	// Handlers that apply patches to the Cluster object and its objects.
-	// Used by CAPI's GeneratePatches hook.
-	genericPatchHandlers := []handlers.Named{
-		httpproxy.NewPatch(mgr.GetClient()),
-		extraapiservercertsans.NewPatch(),
-		auditpolicy.NewPatch(),
-		kubernetesimagerepository.NewPatch(),
-		etcd.NewPatch(),
-	}
-	// Handlers used by CAPI's DiscoverVariables hook.
-	// It's ok that this does not match patchHandlers.
-	// Some of those handlers may always get applied and not have a corresponding variable.
-	genericVariableHandlers := []handlers.Named{
-		httpproxy.NewVariable(),
-		extraapiservercertsans.NewVariable(),
-		kubernetesimagerepository.NewVariable(),
-	}
+
 	// This genericMetaPatchHandlers combines all other patch and variable handlers under a single handler.
 	// It allows to specify configuration under a single variable.
 	genericMetaPatchHandlers := []mutation.MetaMutater{
-		httpproxy.NewMetaPatch(mgr.GetClient()),
-		extraapiservercertsans.NewMetaPatch(),
 		auditpolicy.NewPatch(),
-		kubernetesimagerepository.NewMetaPatch(),
 		etcd.NewMetaPatch(),
-	}
-	genericMetaHandlers := []handlers.Named{
-		// This Calico handler relies on a variable but does not generate a patch.
-		// Instead it creates other resources in the API.
-		calico.NewMetaHandler(mgr.GetClient(), calicoCNIConfig),
-		nfd.NewMetaHandler(mgr.GetClient(), nfdConfig),
-		genericclusterconfig.NewVariable(),
-		mutation.NewMetaGeneratePatchesHandler("clusterConfigPatch", genericMetaPatchHandlers...),
+		extraapiservercertsans.NewMetaPatch(),
+		httpproxy.NewMetaPatch(mgr.GetClient()),
+		kubernetesimagerepository.NewMetaPatch(),
 	}
 
-	// This awsMetaPatchHandlers combines all AWS patch and variable handlers under a single handler.
+	// awsMetaPatchHandlers combines all AWS patch and variable handlers under a single handler.
 	// It allows to specify configuration under a single variable.
-	awsMetaPatchHandlers := []mutation.MetaMutater{
-		region.NewMetaPatch(),
-	}
+	awsMetaPatchHandlers := append(
+		[]mutation.MetaMutater{
+			region.NewMetaPatch(),
+		},
+		genericMetaPatchHandlers...,
+	)
 	awsMetaHandlers := []handlers.Named{
 		awsclusterconfig.NewVariable(),
 		mutation.NewMetaGeneratePatchesHandler("awsClusterConfigPatch", awsMetaPatchHandlers...),
 	}
 
+	// dockerMetaPatchHandlers combines all Docker patch and variable handlers under a single handler.
+	// It allows to specify configuration under a single variable.
+	dockerMetaPatchHandlers := []mutation.MetaMutater{}
+	dockerMetaHandlers := []handlers.Named{
+		dockerclusterconfig.NewVariable(),
+		mutation.NewMetaGeneratePatchesHandler(
+			"dockerClusterConfigPatch",
+			dockerMetaPatchHandlers...),
+	}
+
 	var allHandlers []handlers.Named
-	allHandlers = append(allHandlers, genericLifeCycleHandlers...)
-	allHandlers = append(allHandlers, genericPatchHandlers...)
-	allHandlers = append(allHandlers, genericVariableHandlers...)
-	allHandlers = append(allHandlers, genericMetaHandlers...)
+	allHandlers = append(allHandlers, genericLifecycleHandlers...)
 	allHandlers = append(allHandlers, awsMetaHandlers...)
+	allHandlers = append(allHandlers, dockerMetaHandlers...)
 
 	runtimeWebhookServer := server.NewServer(runtimeWebhookServerOpts, allHandlers...)
 

cmd/main.go

@@ -21,14 +21,10 @@ spec:
       kind: AWSClusterTemplate
       name: aws-quick-start
   patches:
-    - external:
-        discoverVariablesExtension: clusterconfigvars.capi-runtime-extensions
-        generateExtension: clusterconfigpatch.capi-runtime-extensions
-      name: cluster-config
     - external:
         discoverVariablesExtension: awsclusterconfigvars.capi-runtime-extensions
         generateExtension: awsclusterconfigpatch.capi-runtime-extensions
-      name: aws-cluster-config
+      name: cluster-config
     - definitions:
         - jsonPatches:
             - op: add

examples/capi-quick-start/aws-cluster-class.yaml

@@ -24,8 +24,6 @@ spec:
             cni:
               provider: calico
             nfd: {}
-      - name: awsClusterConfig
-        value: {}
     version: v1.27.5
     workers:
       machineDeployments:

examples/capi-quick-start/aws-cluster.yaml

@@ -22,8 +22,8 @@ spec:
       name: docker-quick-start-cluster
   patches:
     - external:
-        discoverVariablesExtension: clusterconfigvars.capi-runtime-extensions
-        generateExtension: clusterconfigpatch.capi-runtime-extensions
+        discoverVariablesExtension: dockerclusterconfigvars.capi-runtime-extensions
+        generateExtension: dockerclusterconfigpatch.capi-runtime-extensions
       name: cluster-config
     - definitions:
         - jsonPatches: