feat(block_volume): support migration from instance volume

internal/services/block/helpers_block.go

@@ -9,8 +9,10 @@ import (
 	block "github.com/scaleway/scaleway-sdk-go/api/block/v1alpha1"
 	"github.com/scaleway/scaleway-sdk-go/api/instance/v1"
 	"github.com/scaleway/scaleway-sdk-go/scw"
+	"github.com/scaleway/terraform-provider-scaleway/v2/internal/httperrors"
 	"github.com/scaleway/terraform-provider-scaleway/v2/internal/locality/zonal"
 	"github.com/scaleway/terraform-provider-scaleway/v2/internal/meta"
+	"github.com/scaleway/terraform-provider-scaleway/v2/internal/services/instance/instancehelpers"
 )
 
 const (
@@ -53,3 +55,42 @@ func customDiffCannotShrink(key string) schema.CustomizeDiffFunc {
 		return oldValue < newValue
 	})
 }
+
+func migrateInstanceToBlockVolume(ctx context.Context, api *instancehelpers.BlockAndInstanceAPI, zone scw.Zone, volumeID string, timeout time.Duration) (*block.Volume, error) {
+	instanceVolumeResp, err := api.GetVolume(&instance.GetVolumeRequest{
+		Zone:     zone,
+		VolumeID: volumeID,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	plan, err := api.PlanBlockMigration(&instance.PlanBlockMigrationRequest{
+		Zone:     instanceVolumeResp.Volume.Zone,
+		VolumeID: &instanceVolumeResp.Volume.ID,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	err = api.ApplyBlockMigration(&instance.ApplyBlockMigrationRequest{
+		Zone:          instanceVolumeResp.Volume.Zone,
+		VolumeID:      &instanceVolumeResp.Volume.ID,
+		ValidationKey: plan.ValidationKey,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = instancehelpers.WaitForVolume(ctx, api.API, zone, volumeID, timeout)
+	if err != nil && !httperrors.Is404(err) {
+		return nil, err
+	}
+
+	blockVolume, err := waitForBlockVolume(ctx, api.BlockAPI, zone, volumeID, timeout)
+	if err != nil {
+		return nil, err
+	}
+
+	return blockVolume, nil
+}