dep: add github.com/ceph/go-ceph for rbd API

Signed-off-by: Niels de Vos <ndevos@redhat.com>

vendor/github.com/ceph/go-ceph/rbd/rbd_nautilus.go

@@ -0,0 +1,45 @@
+// +build !luminous,!mimic
+//
+// Ceph Nautilus is the first release that includes rbd_list2().
+
+package rbd
+
+// #cgo LDFLAGS: -lrbd
+// #include <rados/librados.h>
+// #include <rbd/librbd.h>
+// #include <errno.h>
+import "C"
+
+import (
+	"fmt"
+	"unsafe"
+
+	"github.com/ceph/go-ceph/rados"
+)
+
+// GetImageNames returns the list of current RBD images.
+func GetImageNames(ioctx *rados.IOContext) ([]string, error) {
+	size := C.size_t(0)
+	ret := C.rbd_list2(C.rados_ioctx_t(ioctx.Pointer()), nil, &size)
+	if ret < 0 && ret != -C.ERANGE {
+		return nil, RBDError(ret)
+	} else if ret > 0 {
+		return nil, fmt.Errorf("rbd_list2() returned %d names, expected 0", ret)
+	} else if ret == 0 && size == 0 {
+		return nil, nil
+	}
+
+	// expected: ret == -ERANGE, size contains number of image names
+	images := make([]C.rbd_image_spec_t, size)
+	ret = C.rbd_list2(C.rados_ioctx_t(ioctx.Pointer()), (*C.rbd_image_spec_t)(unsafe.Pointer(&images[0])), &size)
+	if ret < 0 {
+		return nil, RBDError(ret)
+	}
+	defer C.rbd_image_spec_list_cleanup((*C.rbd_image_spec_t)(unsafe.Pointer(&images[0])), size)
+
+	names := make([]string, size)
+	for i, image := range images {
+		names[i] = C.GoString(image.name)
+	}
+	return names, nil
+}