[backups] Scaffold a Velero strategy (#1742)

## What this PR does

This patch adds boilerplate code for a Velero strategy for the backups
API. Implementation can be added into the Reconcile function in a
subsequent PR.

###

```release-note
[backups] Add the boilerplate for a new Velero strategy for backups.
```

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added Velero as a supported backup strategy, including a
cluster-scoped Velero resource type and CRD for creating Velero-backed
strategies.
* Backup job controller updated to recognize and dispatch Velero-backed
jobs, with status conditions exposed for monitoring progress and health.
* Introduced basic reconciliation flow for Velero strategy to enable
future behavior and observability.

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

api/backups/strategy/v1alpha1/velero_types.go

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: Apache-2.0
+// Package v1alpha1 defines strategy.backups.cozystack.io API types.
+//
+// Group: strategy.backups.cozystack.io
+// Version: v1alpha1
+package v1alpha1
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+func init() {
+	SchemeBuilder.Register(func(s *runtime.Scheme) error {
+		s.AddKnownTypes(GroupVersion,
+			&Velero{},
+			&VeleroList{},
+		)
+		return nil
+	})
+}
+
+const (
+	VeleroStrategyKind = "Velero"
+)
+
+// +kubebuilder:object:root=true
+// +kubebuilder:subresource:status
+// +kubebuilder:resource:scope=Cluster
+
+// Velero defines a backup strategy using Velero as the driver.
+type Velero struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	Spec   VeleroSpec   `json:"spec,omitempty"`
+	Status VeleroStatus `json:"status,omitempty"`
+}
+
+// +kubebuilder:object:root=true
+
+// VeleroList contains a list of Velero backup strategies.
+type VeleroList struct {
+	metav1.TypeMeta `json:",inline"`
+	metav1.ListMeta `json:"metadata,omitempty"`
+	Items           []Velero `json:"items"`
+}
+
+// VeleroSpec specifies the desired strategy for backing up with Velero.
+type VeleroSpec struct{}
+
+type VeleroStatus struct {
+	Conditions []metav1.Condition `json:"conditions,omitempty"`
+}

api/backups/strategy/v1alpha1/zz_generated.deepcopy.go

@@ -121,3 +121,99 @@ func (in *JobStatus) DeepCopy() *JobStatus {
 	in.DeepCopyInto(out)
 	return out
 }
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *Velero) DeepCopyInto(out *Velero) {
+	*out = *in
+	out.TypeMeta = in.TypeMeta
+	in.ObjectMeta.DeepCopyInto(&out.ObjectMeta)
+	out.Spec = in.Spec
+	in.Status.DeepCopyInto(&out.Status)
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new Velero.
+func (in *Velero) DeepCopy() *Velero {
+	if in == nil {
+		return nil
+	}
+	out := new(Velero)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *Velero) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *VeleroList) DeepCopyInto(out *VeleroList) {
+	*out = *in
+	out.TypeMeta = in.TypeMeta
+	in.ListMeta.DeepCopyInto(&out.ListMeta)
+	if in.Items != nil {
+		in, out := &in.Items, &out.Items
+		*out = make([]Velero, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new VeleroList.
+func (in *VeleroList) DeepCopy() *VeleroList {
+	if in == nil {
+		return nil
+	}
+	out := new(VeleroList)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *VeleroList) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *VeleroSpec) DeepCopyInto(out *VeleroSpec) {
+	*out = *in
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new VeleroSpec.
+func (in *VeleroSpec) DeepCopy() *VeleroSpec {
+	if in == nil {
+		return nil
+	}
+	out := new(VeleroSpec)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *VeleroStatus) DeepCopyInto(out *VeleroStatus) {
+	*out = *in
+	if in.Conditions != nil {
+		in, out := &in.Conditions, &out.Conditions
+		*out = make([]v1.Condition, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new VeleroStatus.
+func (in *VeleroStatus) DeepCopy() *VeleroStatus {
+	if in == nil {
+		return nil
+	}
+	out := new(VeleroStatus)
+	in.DeepCopyInto(out)
+	return out
+}

cmd/backupstrategy-controller/main.go

@@ -147,7 +147,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	if err = (&backupcontroller.BackupJobStrategyReconciler{
+	if err = (&backupcontroller.BackupJobReconciler{
 		Client: mgr.GetClient(),
 		Scheme: mgr.GetScheme(),
 	}).SetupWithManager(mgr); err != nil {

internal/backupcontroller/backupjob_controller.go

@@ -0,0 +1,53 @@
+package backupcontroller
+
+import (
+	"context"
+
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/types"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/log"
+
+	strategyv1alpha1 "github.com/cozystack/cozystack/api/backups/strategy/v1alpha1"
+	backupsv1alpha1 "github.com/cozystack/cozystack/api/backups/v1alpha1"
+)
+
+// BackupVeleroStrategyReconciler reconciles BackupJob with a strategy referencing
+// Velero.strategy.backups.cozystack.io objects.
+type BackupJobReconciler struct {
+	client.Client
+	Scheme *runtime.Scheme
+}
+
+func (r *BackupJobReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
+	_ = log.FromContext(ctx)
+	j := &backupsv1alpha1.BackupJob{}
+	err := r.Get(ctx, types.NamespacedName{Namespace: req.Namespace, Name: req.Name}, j)
+	if err != nil {
+		if apierrors.IsNotFound(err) {
+			return ctrl.Result{}, nil
+		}
+		return ctrl.Result{}, err
+	}
+	if j.Spec.StrategyRef.APIGroup == nil || *j.Spec.StrategyRef.APIGroup != strategyv1alpha1.GroupVersion.Group {
+		return ctrl.Result{}, nil
+	}
+	switch j.Spec.StrategyRef.Kind {
+	case strategyv1alpha1.JobStrategyKind:
+		return r.reconcileJob(ctx, j)
+	case strategyv1alpha1.VeleroStrategyKind:
+		return r.reconcileVelero(ctx, j)
+	default:
+		return ctrl.Result{}, nil
+	}
+
+}
+
+// SetupWithManager registers our controller with the Manager and sets up watches.
+func (r *BackupJobReconciler) SetupWithManager(mgr ctrl.Manager) error {
+	return ctrl.NewControllerManagedBy(mgr).
+		For(&backupsv1alpha1.BackupJob{}).
+		Complete(r)
+}

internal/backupcontroller/jobstrategy_controller.go

@@ -3,29 +3,13 @@ package backupcontroller
 import (
 	"context"
 
-	"k8s.io/apimachinery/pkg/runtime"
 	ctrl "sigs.k8s.io/controller-runtime"
-	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/log"
 
 	backupsv1alpha1 "github.com/cozystack/cozystack/api/backups/v1alpha1"
 )
 
-// BackupJobStrategyReconciler reconciles BackupJob with a strategy referencing
-// Job.strategy.backups.cozystack.io objects.
-type BackupJobStrategyReconciler struct {
-	client.Client
-	Scheme *runtime.Scheme
-}
-
-func (r *BackupJobStrategyReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
+func (r *BackupJobReconciler) reconcileJob(ctx context.Context, j *backupsv1alpha1.BackupJob) (ctrl.Result, error) {
 	_ = log.FromContext(ctx)
 	return ctrl.Result{}, nil
 }
-
-// SetupWithManager registers our controller with the Manager and sets up watches.
-func (r *BackupJobStrategyReconciler) SetupWithManager(mgr ctrl.Manager) error {
-	return ctrl.NewControllerManagedBy(mgr).
-		For(&backupsv1alpha1.BackupJob{}).
-		Complete(r)
-}

internal/backupcontroller/velerostrategy_controller.go

@@ -0,0 +1,15 @@
+package backupcontroller
+
+import (
+	"context"
+
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/log"
+
+	backupsv1alpha1 "github.com/cozystack/cozystack/api/backups/v1alpha1"
+)
+
+func (r *BackupJobReconciler) reconcileVelero(ctx context.Context, j *backupsv1alpha1.BackupJob) (ctrl.Result, error) {
+	_ = log.FromContext(ctx)
+	return ctrl.Result{}, nil
+}

packages/system/backupstrategy-controller/definitions/strategy.backups.cozystack.io_veleroes.yaml

@@ -0,0 +1,106 @@
+---
+apiVersion: apiextensions.k8s.io/v1
+kind: CustomResourceDefinition
+metadata:
+  annotations:
+    controller-gen.kubebuilder.io/version: v0.16.4
+  name: veleroes.strategy.backups.cozystack.io
+spec:
+  group: strategy.backups.cozystack.io
+  names:
+    kind: Velero
+    listKind: VeleroList
+    plural: veleroes
+    singular: velero
+  scope: Cluster
+  versions:
+  - name: v1alpha1
+    schema:
+      openAPIV3Schema:
+        description: Velero defines a backup strategy using Velero as the driver.
+        properties:
+          apiVersion:
+            description: |-
+              APIVersion defines the versioned schema of this representation of an object.
+              Servers should convert recognized schemas to the latest internal value, and
+              may reject unrecognized values.
+              More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources
+            type: string
+          kind:
+            description: |-
+              Kind is a string value representing the REST resource this object represents.
+              Servers may infer this from the endpoint the client submits requests to.
+              Cannot be updated.
+              In CamelCase.
+              More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds
+            type: string
+          metadata:
+            type: object
+          spec:
+            description: VeleroSpec specifies the desired strategy for backing up
+              with Velero.
+            type: object
+          status:
+            properties:
+              conditions:
+                items:
+                  description: Condition contains details for one aspect of the current
+                    state of this API Resource.
+                  properties:
+                    lastTransitionTime:
+                      description: |-
+                        lastTransitionTime is the last time the condition transitioned from one status to another.
+                        This should be when the underlying condition changed.  If that is not known, then using the time when the API field changed is acceptable.
+                      format: date-time
+                      type: string
+                    message:
+                      description: |-
+                        message is a human readable message indicating details about the transition.
+                        This may be an empty string.
+                      maxLength: 32768
+                      type: string
+                    observedGeneration:
+                      description: |-
+                        observedGeneration represents the .metadata.generation that the condition was set based upon.
+                        For instance, if .metadata.generation is currently 12, but the .status.conditions[x].observedGeneration is 9, the condition is out of date
+                        with respect to the current state of the instance.
+                      format: int64
+                      minimum: 0
+                      type: integer
+                    reason:
+                      description: |-
+                        reason contains a programmatic identifier indicating the reason for the condition's last transition.
+                        Producers of specific condition types may define expected values and meanings for this field,
+                        and whether the values are considered a guaranteed API.
+                        The value should be a CamelCase string.
+                        This field may not be empty.
+                      maxLength: 1024
+                      minLength: 1
+                      pattern: ^[A-Za-z]([A-Za-z0-9_,:]*[A-Za-z0-9_])?$
+                      type: string
+                    status:
+                      description: status of the condition, one of True, False, Unknown.
+                      enum:
+                      - "True"
+                      - "False"
+                      - Unknown
+                      type: string
+                    type:
+                      description: type of condition in CamelCase or in foo.example.com/CamelCase.
+                      maxLength: 316
+                      pattern: ^([a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*/)?(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])$
+                      type: string
+                  required:
+                  - lastTransitionTime
+                  - message
+                  - reason
+                  - status
+                  - type
+                  type: object
+                type: array
+            type: object
+        type: object
+    served: true
+    storage: true
+    subresources:
+      status: {}