rbd: create a standalone RemoveImage function

Currently, the code only provides a .Remove function on the Image type.
But this is unnecessary as the underlying api only requires an io
context and name. Make a function that matches the underlying api
better.

Signed-off-by: John Mulligan <jmulligan@redhat.com>

rbd/rbd.go

@@ -376,10 +376,7 @@ func (image *Image) Remove() error {
 	if err := image.validate(imageNeedsIOContext | imageNeedsName); err != nil {
 		return err
 	}
-
+	return RemoveImage(image.ioctx, image.name)
-	c_name := C.CString(image.name)
-	defer C.free(unsafe.Pointer(c_name))
-	return GetError(C.rbd_remove(C.rados_ioctx_t(image.ioctx.Pointer()), c_name))
 }
 
 // Trash will move an image into the RBD trash, where it will be protected (i.e., salvageable) for
@@ -1352,3 +1349,13 @@ func CreateImage(ioctx *rados.IOContext, name string, size uint64, rio *RbdImage
 		C.uint64_t(size), C.rbd_image_options_t(rio.options))
 	return GetError(ret)
 }
+
+// RemoveImage removes the specified rbd image.
+//
+// Implements:
+//  int rbd_remove(rados_ioctx_t io, const char *name);
+func RemoveImage(ioctx *rados.IOContext, name string) error {
+	c_name := C.CString(name)
+	defer C.free(unsafe.Pointer(c_name))
+	return GetError(C.rbd_remove(C.rados_ioctx_t(ioctx.Pointer()), c_name))
+}

rbd/rbd_test.go

@@ -169,7 +169,7 @@ func TestCreateImageWithOptions(t *testing.T) {
 	name = GetUUID()
 	err = CreateImage(ioctx, name, 1<<22, options)
 	assert.NoError(t, err)
-	err = GetImage(ioctx, name).Remove()
+	err = RemoveImage(ioctx, name)
 	assert.NoError(t, err)
 
 	// create image with RbdImageOptionOrder
@@ -178,7 +178,7 @@ func TestCreateImageWithOptions(t *testing.T) {
 	name = GetUUID()
 	err = CreateImage(ioctx, name, 1<<22, options)
 	assert.NoError(t, err)
-	err = GetImage(ioctx, name).Remove()
+	err = RemoveImage(ioctx, name)
 	assert.NoError(t, err)
 	options.Clear()
 
@@ -191,7 +191,7 @@ func TestCreateImageWithOptions(t *testing.T) {
 	name = GetUUID()
 	err = CreateImage(ioctx, name, 1<<22, options)
 	assert.NoError(t, err)
-	err = GetImage(ioctx, name).Remove()
+	err = RemoveImage(ioctx, name)
 	assert.NoError(t, err)
 	conn.DeletePool(datapool)
 
@@ -1310,3 +1310,38 @@ func TestOpenImage(t *testing.T) {
 	conn.DeletePool(poolname)
 	conn.Shutdown()
 }
+
+func TestRemoveImage(t *testing.T) {
+	conn := radosConnect(t)
+
+	poolname := GetUUID()
+	err := conn.MakePool(poolname)
+	assert.NoError(t, err)
+
+	ioctx, err := conn.OpenIOContext(poolname)
+	require.NoError(t, err)
+
+	// trying to remove a non-existent image is an error
+	err = RemoveImage(ioctx, "bananarama")
+	require.Error(t, err)
+
+	// create and then remove an image
+	name := GetUUID()
+	err = CreateImage(ioctx, name, 1<<22, NewRbdImageOptions())
+	assert.NoError(t, err)
+
+	imageNames, err := GetImageNames(ioctx)
+	assert.NoError(t, err)
+	assert.Contains(t, imageNames, name)
+
+	err = RemoveImage(ioctx, name)
+	assert.NoError(t, err)
+
+	imageNames, err = GetImageNames(ioctx)
+	assert.NoError(t, err)
+	assert.NotContains(t, imageNames, name)
+
+	ioctx.Destroy()
+	conn.DeletePool(poolname)
+	conn.Shutdown()
+}