Runtime SDK client and Discovery

Co-authored-by: chrischdi <[email protected]>

Makefile

@@ -245,6 +245,7 @@ generate-go-deepcopy-core: $(CONTROLLER_GEN) ## Generate deepcopy go code for co
 		paths=./$(EXP_DIR)/api/... \
 		paths=./$(EXP_DIR)/addons/api/... \
 		paths=./$(EXP_DIR)/runtime/api/... \
+		paths=./$(EXP_DIR)/runtime/hooks/api/... \
 		paths=./cmd/clusterctl/... \
 		paths=./internal/test/builder/...
 

exp/runtime/hooks/api/v1alpha1/common_types.go

@@ -0,0 +1,27 @@
+/*
+Copyright 2022 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1alpha1
+
+// ResponseStatus represents the status of the hook response.
+// +enum
+type ResponseStatus string
+
+const (
+	ResponseStatusSuccess ResponseStatus = "Success"
+
+	ResponseStatusFailure ResponseStatus = "Failure"
+)

exp/runtime/hooks/api/v1alpha1/discovery_types.go

@@ -0,0 +1,86 @@
+/*
+Copyright 2022 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1alpha1
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+	"sigs.k8s.io/cluster-api/internal/runtime/catalog"
+)
+
+type FailurePolicy string
+
+const (
+	// FailurePolicyIgnore means that an error calling the extension is ignored.
+	FailurePolicyIgnore FailurePolicy = "Ignore"
+
+	// FailurePolicyFail means that an error calling the extension causes the admission to fail.
+	FailurePolicyFail FailurePolicy = "Fail"
+)
+
+type Hook struct {
+	// APIVersion is the Version of the Hook
+	APIVersion string `json:"apiVersion"`
+
+	// Name is the name of the hook
+	Name string `json:"name"`
+}
+
+type RuntimeExtension struct {
+	// Name is the name of the RuntimeExtension
+	Name string `json:"name"`
+
+	// Hook defines the specific runtime event for which this RuntimeExtension calls.
+	Hook Hook `json:"hook"`
+
+	// TimeoutSeconds defines the timeout duration for client calls to the Hook
+	TimeoutSeconds *int32 `json:"timeoutSeconds,omitempty"`
+
+	// FailurePolicy defines how failures in calls to the Hook should be handled by a client.
+	FailurePolicy *FailurePolicy `json:"failurePolicy,omitempty"`
+}
+
+// DiscoveryHookRequest foo bar baz.
+// +kubebuilder:object:root=true
+type DiscoveryHookRequest struct {
+	metav1.TypeMeta `json:",inline"`
+}
+
+// DiscoveryHookResponse foo bar baz.
+// +kubebuilder:object:root=true
+type DiscoveryHookResponse struct {
+	metav1.TypeMeta `json:",inline"`
+
+	// Status of the call. One of "Success" or "Failure".
+	Status ResponseStatus `json:"status"`
+
+	// A human-readable description of the status of the call.
+	Message string `json:"message"`
+
+	Extensions []RuntimeExtension `json:"extensions"`
+}
+
+func Discovery(*DiscoveryHookRequest, *DiscoveryHookResponse) {}
+
+func init() {
+	catalogBuilder.RegisterHook(Discovery, &catalog.HookMeta{
+		Tags:        []string{"Discovery"},
+		Summary:     "Discovery endpoint",
+		Description: "Discovery endpoint discovers the supported hook of a runtime extension",
+		Singleton:   true,
+	})
+}

exp/runtime/hooks/api/v1alpha1/doc.go

@@ -0,0 +1,21 @@
+/*
+Copyright 2022 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package v1alpha1 contains the v1alpha1 idl implementation for extension1.
+// +k8s:conversion-gen=sigs.k8s.io/cluster-api/exp/runtime/hooks/api/v1alpha3
+// +kubebuilder:object:generate=true
+// +k8s:openapi-gen=true
+package v1alpha1

exp/runtime/hooks/api/v1alpha1/groupversion_info.go

@@ -0,0 +1,43 @@
+/*
+Copyright 2022 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1alpha1
+
+import (
+	"k8s.io/apimachinery/pkg/runtime/schema"
+
+	"sigs.k8s.io/cluster-api/internal/runtime/catalog"
+)
+
+var (
+	// GroupVersion is group version identifying rpc services defined in this package
+	// and their request and response types.
+	GroupVersion = schema.GroupVersion{Group: "hooks.runtime.cluster.x-k8s.io", Version: "v1alpha1"}
+
+	// catalogBuilder is used to add rpc services and their request and response types
+	// to a Catalog.
+	catalogBuilder = &catalog.Builder{GroupVersion: GroupVersion}
+
+	// AddToCatalog adds rpc services defined in this package and their request and
+	// response types to a catalog.
+	AddToCatalog = catalogBuilder.AddToCatalog
+
+	// localSchemeBuilder provide access to the SchemeBuilder used for managing rpc
+	// method's request and response types defined in this package.
+	// NOTE: this object is required to allow registration of automatically generated
+	// conversions func.
+	localSchemeBuilder = catalogBuilder
+)

internal/runtime/catalog/catalog.go

@@ -334,3 +334,14 @@ func (gvh GroupVersionHook) String() string {
 var emptyGroupVersionHook = GroupVersionHook{}
 
 var emptyGroupVersionKind = schema.GroupVersionKind{}
+
+// GVHToPath calculates the path for a given GroupVersionHook.
+// This func is aligned with Kubernetes paths for cluster-wide resources, e.g.:
+// /apis/storage.k8s.io/v1/storageclasses/standard.
+// Note: name is only appended if set, e.g. the Discovery Hook does not have a name.
+func GVHToPath(gvh GroupVersionHook, name string) string {
+	if name == "" {
+		return fmt.Sprintf("/%s/%s/%s", gvh.Group, gvh.Version, strings.ToLower(gvh.Hook))
+	}
+	return fmt.Sprintf("/%s/%s/%s/%s", gvh.Group, gvh.Version, strings.ToLower(gvh.Hook), strings.ToLower(name))
+}