Raise an error if image is missing on compute

gns3server/compute/error.py

@@ -0,0 +1,41 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2015 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+class NodeError(Exception):
+
+    def __init__(self, message, original_exception=None):
+        super().__init__(message)
+        if isinstance(message, Exception):
+            message = str(message)
+        self._message = message
+        self._original_exception = original_exception
+
+    def __repr__(self):
+        return self._message
+
+    def __str__(self):
+        return self._message
+
+
+class ImageMissingError(Exception):
+    """
+    Raised when an image is missing
+    """
+
+    def __init__(self, image):
+        super().__init__("The image {} is missing".format(image))