Throttle disk write to prevent etcd puking during upgrade

clitools/pkg/controller/osimage/write_throttle_other.go

@@ -0,0 +1,18 @@
+//go:build !linux
+
+package osimage
+
+import "context"
+
+type adaptiveWriteController struct{}
+
+func newAdaptiveWriteController(string) (*adaptiveWriteController, error) {
+	return &adaptiveWriteController{}, nil
+}
+
+func newNoopAdaptiveWriteController() *adaptiveWriteController {
+	return &adaptiveWriteController{}
+}
+
+func (c *adaptiveWriteController) Wait(ctx context.Context, n int) error { return nil }
+func (c *adaptiveWriteController) ObserveWrite(n int, dur interface{})   {}