Made patcher only use libvirt api, and skip changes if guest is running.

.travis.yml

@@ -1,9 +1,20 @@
 sudo: false
+
 language: python
 python:
 - '2.7'
 - '3.4'
 - '3.5'
 - '3.6'
+virtualenv:
+  system_site_packages: true
+
+addons:
+  apt:
+    packages:
+      - python-libvirt
+      - python3-libvirt
+
 install: pip install tox-travis
+
 script: tox

README.md

@@ -1,9 +1,9 @@
 Virsh Patcher ![](https://travis-ci.org/PassthroughPOST/virsh-patcher.svg?branch=master)
 ===================
 
-Simple utility to apply common changes to libvirtd domain xml files.
+Simple utility to apply common changes to libvirtd guests.
 
-Can either edit the xml file directly, or apply the patch via a hack around `virsh edit`.
+Changes will not be applied if the guest is running.
 
 
 Supported Fixes
@@ -36,16 +36,19 @@ $ virshpatcher --error43 --hugepages --host-passthrough win10-guest
 
 ```
 $ virshpatcher --help
-usage: virshpatcher [--error43] [--hugepages] [--host-passthrough]
-                    [--patch PATCH] [--help]
-                    [FILE]
+usage: virshpatcher [--connect URI] [--error43] [--hugepages]
+                    [--host-passthrough] [--patch PATCH] [--help]
+                    [--vendor-id ab1234567890] [--random-vendor-id]
+                    [DOMAIN [DOMAIN ...]]
 
 libvirtd xml patcher
 
 positional arguments:
-  FILE                  XML file to edit, or libvirtd domain.
+  DOMAIN
 
 optional arguments:
+  --connect URI, -c URI
+                        hypervisor connection URI
   --error43             Add fixes for 'error43' with nvidia devices.
   --hugepages           Make guest use hugepages.
   --host-passthrough    Make guest CPU model `host_passthrough`.
@@ -61,7 +64,6 @@ optional arguments:
 Future Improvements
 -----------------------
 
- * Use libvirt API instead of `virsh edit` hack.
  * Add ability to connect PCI devices to guest (By name/pattern/id?)
  * Interactive (?)
  * More tests.

setup.py

@@ -11,7 +11,7 @@
     setup_requires=['pytest-runner'],
     tests_require=['pytest'],
     classifiers=[],
-    install_requires=[],
+    install_requires=['libvirt-python'],
     entry_points={
         'console_scripts': [
             'virshpatcher=virshpatcher.main:main',

tox.ini

@@ -4,4 +4,5 @@ envlist = py27,py34,py35,py36
 [testenv]
 deps=
   pytest
+  libvirt-python
 commands=py.test

virshpatcher/main.py

@@ -7,11 +7,24 @@
 import subprocess
 from xml.etree import ElementTree as ET
 
+import libvirt
+
+RUNNING = {
+    libvirt.VIR_DOMAIN_RUNNING,
+    libvirt.VIR_DOMAIN_PAUSED,
+    libvirt.VIR_DOMAIN_PMSUSPENDED,
+}
 
 parser = argparse.ArgumentParser(
     add_help=False,
     description='libvirtd xml patcher')
 
+parser.add_argument(
+    '--connect', '-c',
+    metavar='URI',
+    help='hypervisor connection URI',
+    default='qemu:///system')
+
 parser.add_argument(
     '--error43',
     help='Add fixes for \'error43\' with nvidia devices.',
@@ -66,35 +79,49 @@ def main():
         patchers.append(inst)
 
     parser.add_argument(
-        'file',
-        help='XML file to edit, or libvirtd domain.',
-        nargs='?',
-        metavar='FILE')
+        'domains',
+        metavar='DOMAIN',
+        nargs='*')
 
     args, remainder = parser.parse_known_args(sys.argv[1:])
+
+
     if args.help:
         parser.print_help()
         exit(1)
 
-    if not args.file:
-        err("No filename or libvirtd domain specified.")
+    if not args.domains:
+        err("No domains provided.")
+        exit(1)
+
+    if not patchers:
+        err("No patches provided.")
         exit(1)
 
-    if os.path.exists(args.file):
-        tree = ET.parse(args.file)
+    warning = False
+
+    connection = libvirt.open(args.connect)
+
+    for domain in args.domains:
+
+        dom = connection.lookupByName(domain)
+        state = dom.info()
+
+        if state[0] in RUNNING:
+            warning = True
+            err("Warning: Domain '{}' is running. Not applying changes. ".format(
+                domain))
+            continue
+
+        print("Patching: {}".format(domain))
+        tree = ET.fromstring(dom.XMLDesc(0))
+
         for p in patchers:
+            print("> Applying: {}".format(p.__class__.__name__))
             p.patch(tree, args)
-        tree.write(args.file)
-
-    else:
-        if args.file != sys.argv[-1]:
-            err("Libvirt domain must be the last argument provided.")
-
-        os.environ['EDITOR'] = " ".join(sys.argv[:-1])
-        cmd = ['virsh', 'edit', args.file]
-        try:
-            ret = subprocess.run(cmd, check=True)
-        except Exception as e:
-            err("Unable to edit domain {!r}".format(args.file))
-            err(e)
-            exit(1)
+
+        xml_str = ET.tostring(tree).decode()
+        connection.defineXML(xml_str)
+
+    if warning:
+        exit(1)

virshpatcher/patcher.py

@@ -12,7 +12,7 @@ def add_arguments(self, parser):
 
     def patch(self, tree, args):
         for patch_set in self.nodes:
-            node = tree.getroot()
+            node = tree
 
             for tag in patch_set:
                 creator = getattr(
@@ -28,6 +28,8 @@ def patch(self, tree, args):
                 new = node.find(tag)
 
                 if new is None:
+                    if isinstance(node, ET.ElementTree):
+                        node = node.getroot()
                     new = ET.SubElement(node, *creator(args))
 
                 patcher(args, new)