From ccb94be2fae6aca94a8a021c0b5602ae68f8d7c4 Mon Sep 17 00:00:00 2001
From: Kushal Das <kushaldas@gmail.com>
Date: Aug 06 2015 11:44:32 +0000
Subject: We can setup the instance default storage.


---

diff --git a/computer/virt.py b/computer/virt.py
index 8179182..996d9a6 100644
--- a/computer/virt.py
+++ b/computer/virt.py
@@ -1,3 +1,4 @@
+import os
 import subprocess
 
 def system(cmd):
@@ -12,3 +13,44 @@ def system(cmd):
     out, err = ret.communicate()
     returncode = ret.returncode
     return out, err, returncode
+
+
+def download_image(url, path):
+    """
+    Downloads an image to a given directory.
+    :param url: URL of the image.
+    :param path: Directory to the file in.
+    :return: If download happens properly, returns True, otherwise False
+    """
+    cmd = 'wget %s -O %s' % (url, os.path.dirname(path))
+    out, err, ret_code = system(cmd)
+    if ret_code:
+        return False
+    return True
+
+
+def setup_instance_storage(image_name, instance_name, path='/var/lib/libvirt/images/',
+                           size='5G', device='/dev/sda1'):
+    """
+    It creates the image to be used in the instance.
+
+    :param image_name: For now, the qcow2 image name (absolute path of the image).
+    :param instance_name: Name of the instance for the storage.
+    :param path: Where this image should go.
+    :param size: New size of the instance.
+    :param device: The partition we should resize.
+    :return: Tuple, (Boolean, str).
+    """
+    file_path = os.path.join(path, '%s.qcow2' % instance_name)
+    cmd = 'qemu-img create -f qcow2 -o preallocation=metadata {0} {1}'.format(file_path, size)
+    out, err, ret_code = system(cmd)
+    if ret_code:
+        return False, 'Storage creation failed.'
+    cmd = 'virt-resize -v --expand {0} {1} {2}'.format(device, image_name, file_path)
+    out, err, ret_code = system(cmd)
+    if ret_code:
+        return False, 'Resize failed.'
+
+    return True, file_path
+
+