[libvirt-users] changeBegin() on python API

[Laine Stump]

On 11/02/2015 09:48 AM, Laine Stump wrote:
> On 10/30/2015 07:02 AM, Michal Privoznik wrote:
>> On 29.10.2015 15:22, Ramon Medeiros wrote:
>>> Hi,
>>>
>>> is changeBegin() working on python? I was trying to use the following
>>> method:
>>>
>>> if = conn.interfaceLookupByName("name")
>>> if.undefine()
>>>
>>> I saw that changeBegin() does not commit changes, but i can't use it.
>>>
>> This python API boils down to virInterfaceChangeBegin() but as such it's
>> implemented just for netcf backend. So if you're on a distro where udev
>> is used instead, the API will return an error.
>> Otherwise, this should work:
>>
>> if = conn.interfaceLookupByName("name")
>> if.changeBegin()
>> if.undefine()
>>
>> /* test if the connectivity to the host was not lost */
>>
>> if.changeCommit()
>
> I haven't ever used the python bindings for the interface APIs, but if 
> changeBegin is implemented as a method of an interface, that is wrong 
> - virInterfaceChangeBegin() saves all the config for *all* interfaces 
> on the host, so it should instead be a method of the connection.

I just tried this out and found that virInterfaceChangeBegin() *is* a 
method of the conn rather than the interface, but it is named 
"changeBegin" rather than "interfaceChangeBegin", which would have made 
more sense (but since the python names are auto-generated, and the 
addition of the new API didn't ring any alarm bells to suggest manual 
intervention in generator.py, the clumsy autogenerated name has stood 
for 4 1/2 years). I suppose it's much too late to change it now :-/

I wonder what kind of semi-automated process we can put in place to 
prevent something like this from happening in the future? A script 
that's run as part of make dist in libvirt-python that creates a list of 
all new libvirt APIs added since the previous release of libvirt-python, 
along with their corresponding names in python?