Method to download file to VMware server

This patch adds a utility method in image_transfer to download
a file to VMware server.

Change-Id: Ic378d21d036f5296310697d73dbc6ee284fdd187

oslo_vmware/image_transfer.py

@@ -137,6 +137,36 @@ def download_flat_image(context, timeout_secs, image_service, image_id,
               image_id)
 
 
+def download_file(
+        read_handle, host, port, dc_name, ds_name, cookies,
+        upload_file_path, file_size, cacerts, timeout_secs):
+    """Download file to VMware server.
+
+    :param read_handle: file read handle
+    :param host: VMware server host name or IP address
+    :param port: VMware server port number
+    :param dc_name: name of the datacenter which contains the destination
+                    datastore
+    :param ds_name: name of the destination datastore
+    :param cookies: cookies to build the cookie header while establishing
+                    http connection with VMware server
+    :param upload_file_path: destination datastore file path
+    :param file_size: source file size
+    :param cacerts: CA bundle file to use for SSL verification
+    :param timeout_secs: timeout in seconds to wait for the download to
+                         complete
+    """
+    write_handle = rw_handles.FileWriteHandle(host,
+                                              port,
+                                              dc_name,
+                                              ds_name,
+                                              cookies,
+                                              upload_file_path,
+                                              file_size,
+                                              cacerts=cacerts)
+    _start_transfer(read_handle, write_handle, timeout_secs)
+
+
 def download_stream_optimized_data(context, timeout_secs, read_handle,
                                    **kwargs):
     """Download stream optimized data to VMware server.

oslo_vmware/tests/test_image_transfer.py

@@ -96,6 +96,32 @@ class ImageTransferUtilityTest(base.TestCase):
             fake_FileWriteHandle,
             timeout_secs)
 
+    @mock.patch('oslo_vmware.rw_handles.FileWriteHandle')
+    @mock.patch.object(image_transfer, '_start_transfer')
+    def test_download_file(self, start_transfer, file_write_handle_cls):
+        write_handle = mock.sentinel.write_handle
+        file_write_handle_cls.return_value = write_handle
+
+        read_handle = mock.sentinel.read_handle
+        host = mock.sentinel.host
+        port = mock.sentinel.port
+        dc_name = mock.sentinel.dc_name
+        ds_name = mock.sentinel.ds_name
+        cookies = mock.sentinel.cookies
+        upload_file_path = mock.sentinel.upload_file_path
+        file_size = mock.sentinel.file_size
+        cacerts = mock.sentinel.cacerts
+        timeout_secs = mock.sentinel.timeout_secs
+        image_transfer.download_file(
+            read_handle, host, port, dc_name, ds_name, cookies,
+            upload_file_path, file_size, cacerts, timeout_secs)
+
+        file_write_handle_cls.assert_called_once_with(
+            host, port, dc_name, ds_name, cookies, upload_file_path,
+            file_size, cacerts=cacerts)
+        start_transfer.assert_called_once_with(
+            read_handle, write_handle, timeout_secs)
+
     @mock.patch('oslo_vmware.rw_handles.VmdkWriteHandle')
     @mock.patch.object(image_transfer, '_start_transfer')
     def test_download_stream_optimized_data(self, fake_transfer,