feat(operator): Enable snapshot on master only (#367)

Signed-off-by: Kathleen <[email protected]>

Author: xuekat

api/v1alpha1/dragonfly_types.go

@@ -218,6 +218,11 @@ type Snapshot struct {
 	// +kubebuilder:validation:Optional
 	Cron string `json:"cron,omitempty"`
 
+	// (Optional) Enable snapshot on master only
+	// +optional
+	// +kubebuilder:validation:Optional
+	EnableOnMasterOnly bool `json:"enableOnMasterOnly,omitempty"`
+
 	// (Optional) Dragonfly PVC spec
 	// +optional
 	// +kubebuilder:validation:Optional

charts/dragonfly-operator/templates/crds.yaml

@@ -3147,6 +3147,9 @@ spec:
                     cron:
                       description: (Optional) Dragonfly snapshot schedule
                       type: string
+                    enableOnMasterOnly:
+                      description: (Optional) Enable snapshot on master only
+                      type: boolean
                     dir:
                       description: |-
                         (Optional) The path to the snapshot directory

config/crd/bases/dragonflydb.io_dragonflies.yaml

@@ -6388,6 +6388,9 @@ spec:
                       This can also be an S3 URI with the prefix `s3://` when
                       using S3 as the snapshot backend
                     type: string
+                  enableOnMasterOnly:
+                    description: (Optional) Enable snapshot on master only
+                    type: boolean
                   persistentVolumeClaimSpec:
                     description: (Optional) Dragonfly PVC spec
                     properties:

config/samples/pvc.yaml

@@ -19,6 +19,7 @@ spec:
       memory: 750Mi
   snapshot:
     cron: "*/5 * * * *"
+    enableOnMasterOnly: false
     persistentVolumeClaimSpec:
       accessModes:
       - ReadWriteOnce

internal/controller/dragonfly_instance.go

@@ -390,6 +390,13 @@ func (dfi *DragonflyInstance) replicaOf(ctx context.Context, pod *corev1.Pod, ma
 		return fmt.Errorf("response of `SLAVE OF` on replica is not OK: %s", resp)
 	}
 
+	if dfi.df.Spec.Snapshot != nil && dfi.df.Spec.Snapshot.EnableOnMasterOnly {
+		dfi.log.Info("clearing snapshot cron schedule on replica", "pod", pod.Name)
+		if _, err := redisClient.ConfigSet(ctx, "snapshot_cron", "").Result(); err != nil {
+			return fmt.Errorf("failed to clear snapshot_cron on replica %s: %w", pod.Name, err)
+		}
+	}
+
 	dfi.log.Info("marking pod role as replica", "pod", pod.Name)
 	patchFrom := client.MergeFrom(pod.DeepCopy())
 	pod.Labels[resources.RoleLabelKey] = resources.Replica
@@ -418,6 +425,14 @@ func (dfi *DragonflyInstance) replicaOfNoOne(ctx context.Context, pod *corev1.Po
 		return fmt.Errorf("response of `SLAVE OF NO ONE` on master is not OK: %s", resp)
 	}
 
+	if dfi.df.Spec.Snapshot != nil && dfi.df.Spec.Snapshot.EnableOnMasterOnly {
+		dfi.log.Info("setting snapshot cron schedule on master", "pod", pod.Name)
+		cron := dfi.df.Spec.Snapshot.Cron
+		if _, err := redisClient.ConfigSet(ctx, "snapshot_cron", cron).Result(); err != nil {
+			return fmt.Errorf("failed to set snapshot_cron on master %s: %w", pod.Name, err)
+		}
+	}
+
 	dfi.log.Info("marking pod role as master", "pod", pod.Name)
 	patchFrom := client.MergeFrom(pod.DeepCopy())
 	pod.Labels[resources.RoleLabelKey] = resources.Master

internal/controller/dragonfly_pod_lifecycle_controller.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+
 	"github.com/dragonflydb/dragonfly-operator/internal/resources"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/types"

manifests/crd.yaml

@@ -6380,7 +6380,10 @@ spec:
                 properties:
                   cron:
                     description: (Optional) Dragonfly snapshot schedule
-                    type: string
+                    type: string  
+                  enableOnMasterOnly:
+                    description: (Optional) Enable snapshot on master only
+                    type: boolean
                   dir:
                     description: |-
                       (Optional) The path to the snapshot directory

manifests/dragonfly-operator.yaml

@@ -6394,6 +6394,9 @@ spec:
                   cron:
                     description: (Optional) Dragonfly snapshot schedule
                     type: string
+                  enableOnMasterOnly:
+                    description: (Optional) Enable snapshot on master only
+                    type: boolean
                   dir:
                     description: |-
                       (Optional) The path to the snapshot directory