feat(instance): add a wait on volume (#418)

api/instance/v1/volume_utils.go

@@ -0,0 +1,50 @@
+package instance
+
+import (
+	"time"
+
+	"github.com/scaleway/scaleway-sdk-go/internal/async"
+	"github.com/scaleway/scaleway-sdk-go/internal/errors"
+	"github.com/scaleway/scaleway-sdk-go/scw"
+)
+
+// WaitForImageRequest is used by WaitForImage method.
+type WaitForVolumeRequest struct {
+	VolumeID string
+	Zone     scw.Zone
+	Timeout  time.Duration
+}
+
+// WaitForSnapshot wait for the snapshot to be in a "terminal state" before returning.
+func (s *API) WaitForVolume(req *WaitForVolumeRequest) (*Volume, error) {
+	if req.Timeout == 0 {
+		req.Timeout = defaultTimeout
+	}
+
+	terminalStatus := map[VolumeState]struct{}{
+		VolumeStateAvailable: {},
+		VolumeStateError:     {},
+	}
+
+	volume, err := async.WaitSync(&async.WaitSyncConfig{
+		Get: func() (interface{}, bool, error) {
+			res, err := s.GetVolume(&GetVolumeRequest{
+				VolumeID: req.VolumeID,
+				Zone:     req.Zone,
+			})
+
+			if err != nil {
+				return nil, false, err
+			}
+			_, isTerminal := terminalStatus[res.Volume.State]
+
+			return res.Volume, isTerminal, err
+		},
+		Timeout:          req.Timeout,
+		IntervalStrategy: async.LinearIntervalStrategy(RetryInterval),
+	})
+	if err != nil {
+		return nil, errors.Wrap(err, "waiting for volume failed")
+	}
+	return volume.(*Volume), nil
+}