virt.init: fix disk target names

Fixes issue #57477.

changelog/57477.fixed

@@ -0,0 +1 @@
+virt.init fix the disk target names

salt/modules/virt.py

@@ -712,15 +712,17 @@ def _gen_xml(
 
     context["disks"] = []
     disk_bus_map = {"virtio": "vd", "xen": "xvd", "fdc": "fd", "ide": "hd"}
+    targets = []
     for i, disk in enumerate(diskp):
         prefix = disk_bus_map.get(disk["model"], "sd")
         disk_context = {
             "device": disk.get("device", "disk"),
-            "target_dev": "{0}{1}".format(prefix, string.ascii_lowercase[i]),
+            "target_dev": _get_disk_target(targets, len(diskp), prefix),
             "disk_bus": disk["model"],
             "format": disk.get("format", "raw"),
             "index": six.text_type(i),
         }
+        targets.append(disk_context["target_dev"])
         if disk.get("source_file"):
             url = urlparse(disk["source_file"])
             if not url.scheme or not url.hostname:
@@ -2115,6 +2117,21 @@ def _remove_indent(node):
     return diff
 
 
+def _get_disk_target(targets, disks_count, prefix):
+    """
+    Compute the disk target name for a given prefix.
+
+    :param targets: the list of already computed targets
+    :param disks: the number of disks
+    :param prefix: the prefix of the target name, i.e. "hd"
+    """
+    return [
+        "{0}{1}".format(prefix, string.ascii_lowercase[i])
+        for i in range(disks_count)
+        if "{0}{1}".format(prefix, string.ascii_lowercase[i]) not in targets
+    ][0]
+
+
 def _diff_disk_lists(old, new):
     """
     Compare disk definitions to extract the changes and fix target devices
@@ -2131,11 +2148,7 @@ def _diff_disk_lists(old, new):
         target_node = disk.find("target")
         target = target_node.get("dev")
         prefix = [item for item in prefixes if target.startswith(item)][0]
-        new_target = [
-            "{0}{1}".format(prefix, string.ascii_lowercase[i])
-            for i in range(len(new))
-            if "{0}{1}".format(prefix, string.ascii_lowercase[i]) not in targets
-        ][0]
+        new_target = _get_disk_target(targets, len(new), prefix)
         target_node.set("dev", new_target)
         targets.append(new_target)
 

tests/unit/modules/test_virt.py

@@ -803,7 +803,10 @@ def test_gen_xml_for_kvm_custom_profile(self):
             self.assertEqual(root.find("vcpu").text, "1")
             self.assertEqual(root.find("memory").text, six.text_type(512 * 1024))
             self.assertEqual(root.find("memory").attrib["unit"], "KiB")
-            self.assertTrue(len(root.findall(".//disk")) == 2)
+            disks = root.findall(".//disk")
+            self.assertTrue(len(disks) == 2)
+            self.assertEqual(disks[0].find("target").get("dev"), "vda")
+            self.assertEqual(disks[1].find("target").get("dev"), "vdb")
             self.assertTrue(len(root.findall(".//interface")) == 2)
 
     def test_disk_profile_kvm_disk_pool(self):
@@ -1137,11 +1140,15 @@ def test_gen_xml_cdrom(self):
         """
         Test virt._gen_xml(), generating a cdrom device (different disk type, no source)
         """
+        self.mock_conn.storagePoolLookupByName.return_value.XMLDesc.return_value = (
+            "<pool type='dir'/>"
+        )
         diskp = virt._disk_profile(
             self.mock_conn,
             None,
             "kvm",
             [
+                {"name": "system", "pool": "default"},
                 {
                     "name": "tested",
                     "device": "cdrom",
@@ -1162,12 +1169,13 @@ def test_gen_xml_cdrom(self):
             self.mock_conn, "hello", 1, 512, diskp, nicp, "kvm", "hvm", "x86_64",
         )
         root = ET.fromstring(xml_data)
-        disk = root.findall(".//disk")[0]
+        disk = root.findall(".//disk")[1]
         self.assertEqual(disk.get("type"), "file")
         self.assertEqual(disk.attrib["device"], "cdrom")
         self.assertIsNone(disk.find("source"))
+        self.assertEqual(disk.find("target").get("dev"), "hda")
 
-        disk = root.findall(".//disk")[1]
+        disk = root.findall(".//disk")[2]
         self.assertEqual(disk.get("type"), "network")
         self.assertEqual(disk.attrib["device"], "cdrom")
         self.assertEqual(