[CRIU] rewriting images via criu (or crit?)

[Ruslan Kuprieiev]

On 23.10.2014 19:36, Pavel Emelyanov wrote:
> On 10/21/2014 04:58 PM, Tycho Andersen wrote:
>> On Tue, Oct 21, 2014 at 01:22:06PM +0400, Cyrill Gorcunov wrote:
>>> On Tue, Oct 21, 2014 at 12:13:06PM +0300, Ruslan Kuprieiev wrote:
>>>>> As to me -- external tool for such modifications is better choise and it seems
>>>>> crit is exactly fits here. This might have slight impact on the speed in compare
>>>>> if the language would builtin into criu itself, but criu is already complex enough
>>>>> so adding language engine here would simply overload I think.
>>>> I totally agree with Cyrill.
>>>>
>>>> I like the syntax. Are you thinking about using crit like so:
>>>> crit modify -i cgroup.img cgroup_entry.controllers["cpuset" in
>>>> cnames]//properties[name="cpuset.cpus"] set value=0-1
>>>> right?
>>> I guess so. Also I would consider introdusing more human-readable
>>> syntax if possible, but that's optional, up to you and Tycho.
>> Suggestions are welcome; I just picked this because xpath is the only
>> language I could think of that has similar goals, so it might be
>> something that people were familiar with.
> I like the idea of xpath language, it seems to be suitable for images.
>
> BTW, In criu images we have a feature that differs them from xml -- we
> have arrays of similar messages in many files, e.g. in reg-files. What
> if we want to edit paths only on entries, that match some criteria,
> e.g. we moved /home/foo into /home/bar and want to s#/home/foo#/home/bar#,
> but leave all the other paths (e.g. /etc/*) intact. Will we be able to
> construct the xpath expression to address that?
>
>
> Nonetheless, Ruslan, can you (after finishing with basic crit stuff) find
> out whether there's standard python library for xpath and how fast/slow
> it is? :)

Ok.
I will try to make some research on this whole "image modification
language" task too.

> Thanks,
> Pavel
>