cli: Add xpath.* subargs to XML options

This adds the power of --xml to individual device options. For example
this makes it easier to make custom XML changes for a single --disk
device from both virt-install and virt-xml

Signed-off-by: Cole Robinson <crobinso@redhat.com>

man/virt-install.rst

@@ -258,6 +258,24 @@ The --xml option has 4 sub options:
 
 
 
+**xpath subarguments**
+``````````````````````
+
+Similar to the ``--xml`` option, most top level options have ``xpath.*``
+suboptions. For example, ``--disk xpath1.set=./@foo=bar,xpath2.create=./newelement``
+would generate XML alterations like
+
+.. code-block::
+
+       <disk foo="bar">
+         <newelements/>
+       </disk>
+
+This is useful for setting XML options per device, when virt-install does not
+support those options yet.
+
+
+
 ``--qemu-commandline``
 ^^^^^^^^^^^^^^^^^^^^^^
 

tests/data/cli/compare/virt-install-many-devices.xml

@@ -657,6 +657,10 @@
     <input type="evdev">
       <source dev="/dev/input/event1234" repeat="on" grab="all" grabToggle="ctrl-ctrl"/>
     </input>
+    <input type="keyboard" bus="usb">
+      <address type="usb"/>
+      <randomelement/>
+    </input>
     <tpm model="tpm-crb">
       <backend type="passthrough" version="2.0" persistent_state="yes">
         <device path="/dev/tpm0"/>

tests/data/cli/compare/virt-xml-edit-device-xpath.xml

@@ -0,0 +1,15 @@
+   <devices>
+     <emulator>/usr/lib/xen/bin/qemu-dm</emulator>
+     <disk type="block" device="floppy">
+-      <source dev="/dev/null"/>
+       <target dev="fda" bus="fdc"/>
+-      <boot order="5"/>
++      <boot order="6"/>
+       <address type="drive" controller="0" bus="0" target="0" unit="0"/>
++      <fakeelement/>
+     </disk>
+     <disk type="file" device="disk">
+       <source file="/tmp/foobar"/>
+
+Domain 'test-for-virtxml' defined successfully.
+Changes will take effect after the domain is fully powered off.

tests/test_cli.py

@@ -646,6 +646,7 @@ source.reservations.managed=no,source.reservations.source.type=unix,source.reser
 --input mouse,bus=virtio,model=virtio-non-transitional
 --input passthrough,source.evdev=/dev/input/event1,bus=virtio
 --input evdev,source.dev=/dev/input/event1234,source.repeat=on,source.grab=all,source.grabToggle=ctrl-ctrl
+--input mouse,model=FOOBAR,xpath0.set=./@bus=usb,xpath2.set=./address/@type=usb,xpath6.set=./willbeoverwritten=foo,xpath6.create=./randomelement,xpath7.create=./deleteme,xpath8.delete=./deleteme,xpath9.set=./@model=,xpath10.set=./@type,xpath10.value=keyboard
 
 
 --serial char_type=tcp,host=:2222,mode=bind,protocol=telnet,log.file=/tmp/foo.log,log.append=yes,,target.model.name=pci-serial
@@ -1360,6 +1361,7 @@ c.add_compare("--clock offset=localtime,hpet_present=yes,kvmclock_present=no,kvm
 c.add_compare("--pm suspend_to_mem.enabled=yes,suspend_to_disk.enabled=no", "edit-simple-pm")
 c.add_compare("--disk /dev/zero,perms=ro,source.startupPolicy=optional", "edit-simple-disk")
 c.add_compare("--disk path=", "edit-simple-disk-remove-path")
+c.add_compare("--disk xpath1.delete=./source,xpath2.set=./boot/@order,xpath2.value=6,xpath3.create=./fakeelement", "edit-device-xpath")
 c.add_compare("--network source=br0,type=bridge,model=virtio,mac=", "edit-simple-network")
 c.add_compare("--graphics tlsport=5902,keymap=ja", "edit-simple-graphics")
 c.add_compare("--graphics listen=none", "edit-graphics-listen-none")

virtinst/cli.py

@@ -1366,6 +1366,8 @@ class VirtCLIParser(metaclass=_InitClass):
                 prefix = "0"
             if virtarg.cliname.startswith("address."):
                 prefix = "1"
+            if virtarg.cliname.startswith("xpath"):
+                prefix = "2"
             return prefix + virtarg.cliname
 
         print("%s options:" % cls.cli_flag_name())
@@ -1400,7 +1402,9 @@ class VirtCLIParser(metaclass=_InitClass):
 
     @staticmethod
     def _virtcli_class_init_common(subclass):
-        pass
+        if subclass and subclass.guest_propname:
+            _add_xpath_args(subclass)
+
 
     def __init__(self, optstr, guest=None, editing=None):
         self.optstr = optstr
@@ -1615,6 +1619,31 @@ def parse_xmlcli(guest, options):
         guest.xml_actions.append(inst)
 
 
+def _add_xpath_args(cls):
+    """
+    Add xpath.* subarguments to XML based CLI options
+    """
+    def find_xpath_cb(self, *args, **kwargs):
+        cliarg = "xpath"  # xpath[0-9]*
+        list_propname = "xml_actions"
+        # pylint: disable=protected-access
+        cb = self._make_find_inst_cb(cliarg, list_propname)
+        return cb(*args, **kwargs)
+
+    def _add_arg(*args, **kwargs):
+        kwargs["skip_testsuite_tracking"] = True
+        cls.add_arg(*args, **kwargs)
+
+    _add_arg("xpath[0-9]*.delete", "xpath_delete",
+            can_comma=True, lookup_cb=None, find_inst_cb=find_xpath_cb)
+    _add_arg("xpath[0-9]*.set", "xpath_set",
+            can_comma=True, lookup_cb=None, find_inst_cb=find_xpath_cb)
+    _add_arg("xpath[0-9]*.create", "xpath_create",
+            can_comma=True, lookup_cb=None, find_inst_cb=find_xpath_cb)
+    _add_arg("xpath[0-9]*.value", "xpath_value",
+            can_comma=True, lookup_cb=None, find_inst_cb=find_xpath_cb)
+
+
 ########################
 # --unattended parsing #
 ########################
@@ -4422,6 +4451,7 @@ class _ParserChar(VirtCLIParser):
 
         VirtCLIParser._virtcli_class_init_common(cls)
         _add_common_device_args(cls)
+        _add_xpath_args(cls)
 
         cls.add_arg("type", "type")