Rewrote image search

This code is more generic and support all cases. Previously
we had bug where the user lost his image path if the image
was not located in image directory.

gns3server/modules/dynamips/__init__.py

@@ -616,3 +616,9 @@ class Dynamips(BaseManager):
             if was_auto_started:
                 yield from vm.stop()
         return validated_idlepc
+
+    def get_images_directory(self):
+        """
+        Return the full path of the images directory on disk
+        """
+        return os.path.join(os.path.expanduser(self.config.get_section_config("Server").get("images_path", "~/GNS3/images")), "IOS")

gns3server/modules/dynamips/nodes/router.py

@@ -151,10 +151,7 @@ class Router(BaseVM):
                        "system_id": self._system_id}
 
         # return the relative path if the IOS image is in the images_path directory
-        server_config = self.manager.config.get_section_config("Server")
-        relative_image = os.path.join(os.path.expanduser(server_config.get("images_path", "~/GNS3/images")), "IOS", self._image)
-        if os.path.exists(relative_image):
-            router_info["image"] = os.path.basename(self._image)
+        router_info["image"] = self.manager.get_relative_image_path(self._image)
 
         # add the slots
         slot_number = 0
@@ -427,9 +424,7 @@ class Router(BaseVM):
         :param image: path to IOS image file
         """
 
-        if not os.path.isabs(image):
-            server_config = self.manager.config.get_section_config("Server")
-            image = os.path.join(os.path.expanduser(server_config.get("images_path", "~/GNS3/images")), "IOS", image)
+        image = self.manager.get_abs_image_path(image)
 
         if not os.path.isfile(image):
             raise DynamipsError("IOS image '{}' is not accessible".format(image))