virt: handle cdrom remote images

Libvirt allows to use network images for cdroms. Use them if the image
is a remote URL for a cdrom device.

salt/modules/virt.py

@@ -87,6 +87,7 @@ import subprocess
 import sys
 import time
 from xml.etree import ElementTree
+from xml.sax import saxutils
 
 # Import third party libs
 import jinja2
@@ -107,6 +108,7 @@ from salt._compat import ipaddress
 from salt.exceptions import CommandExecutionError, SaltInvocationError
 from salt.ext import six
 from salt.ext.six.moves import range  # pylint: disable=import-error,redefined-builtin
+from salt.ext.six.moves.urllib.parse import urlparse
 from salt.utils.virt import check_remote, download_remote
 
 try:
@@ -691,8 +693,17 @@ def _gen_xml(
             "index": six.text_type(i),
         }
         if disk.get("source_file"):
-            disk_context["source_file"] = disk["source_file"]
-            disk_context["type"] = "file"
+            url = urlparse(disk["source_file"])
+            if not url.scheme or not url.hostname:
+                disk_context["source_file"] = disk["source_file"]
+                disk_context["type"] = "file"
+            elif url.scheme in ["http", "https", "ftp", "ftps", "tftp"]:
+                disk_context["type"] = "network"
+                disk_context["protocol"] = url.scheme
+                disk_context["volume"] = url.path
+                disk_context["query"] = saxutils.escape(url.query)
+                disk_context["hosts"] = [{"name": url.hostname, "port": url.port}]
+
         elif disk.get("pool"):
             disk_context["volume"] = disk["filename"]
             # If we had no source_file, then we want a volume

salt/templates/virt/libvirt_domain.jinja

@@ -36,7 +36,7 @@
                         <source pool='{{ disk.pool }}' volume='{{ disk.volume }}' />
                         {% endif %}
                         {%- if disk.type == 'network' %}
-                        <source protocol='{{ disk.protocol }}' name='{{ disk.volume }}'>
+                        <source protocol='{{ disk.protocol }}' name='{{ disk.volume }}'{% if disk.get('query') %} query='{{ disk.query }}'{% endif %}>
                           {%- for host in disk.get('hosts') %}
                           <host name='{{ host.name }}'{% if host.get("port") %} port='{{ host.port }}'{% endif %}/>
                           {%- endfor %}

tests/unit/modules/test_virt.py

@@ -1125,7 +1125,13 @@ class VirtTestCase(TestCase, LoaderModuleMockMixin):
                     "device": "cdrom",
                     "source_file": None,
                     "model": "ide",
-                }
+                },
+                {
+                    "name": "remote",
+                    "device": "cdrom",
+                    "source_file": "http://myhost:8080/url/to/image?query=foo&filter=bar",
+                    "model": "ide",
+                },
             ],
             "hello",
         )
@@ -1139,6 +1145,19 @@ class VirtTestCase(TestCase, LoaderModuleMockMixin):
         self.assertEqual(disk.attrib["device"], "cdrom")
         self.assertIsNone(disk.find("source"))
 
+        disk = root.findall(".//disk")[1]
+        self.assertEqual(disk.get("type"), "network")
+        self.assertEqual(disk.attrib["device"], "cdrom")
+        self.assertEqual(
+            {
+                "protocol": "http",
+                "name": "/url/to/image",
+                "query": "query=foo&filter=bar",
+                "host": {"name": "myhost", "port": "8080"},
+            },
+            salt.utils.xmlutil.to_dict(disk.find("source"), True),
+        )
+
     def test_controller_for_esxi(self):
         """
         Test virt._gen_xml() generated device controller for ESXi/vmware