Detect LXC version from VagrantFile

Since the configuration keys have changed in LXC version 3. I would like to be able to detect the version used inside my Vagrant file.
I found no way to access the driver's method `supports_new_config_format

vagrant-lxc/lib/vagrant-lxc/driver.rb

Line 218 in dd24cdc

def supports_new_config_format

Is there a way to do it ?

I would like to adapt something like this:

config.vm.provider "lxc" do |lxc, override|
  lxc.customize 'aa_profile', 'unconfined'
end

To

config.vm.provider "lxc" do |lxc, override|
  if lxc.supports_new_config_format
   lxc.customize 'apparmor.profile', 'unconfined'
 else
   lxc.customize 'aa_profile', 'unconfined'
 end
end

Thanks for your help !

@ragusa87 It may be impossible expose support_new_config_format , because configuration interface is running before driver instance created.

You can add parameter to select lxc customization such as

require 'getoptlong'

opts = GetoptLong.new(
  [ '--lxc-new-config', GetoptLong::OPTIONAL_ARGUMENT ]
)
opts.ordering=(GetoptLong::REQUIRE_ORDER) 

is_lxc3=false

opts.each do |opt, arg|
  case opt
    when '--lxc-new-config'
      is_lxc3=true
  end
end

config.vm.provider "lxc" do |lxc, override|
  if is_lxc3
   lxc.customize 'apparmor.profile', 'unconfined'
 else
   lxc.customize 'aa_profile', 'unconfined'
 end
end

reference: SO How to pass parameter on 'vagrant up' and have it in the scope of Vagrantfile?

and add a document to help user to set it according to their environment.

Thanks for the update @miurahr.
We migrated all our boxes to LXC 3 in the meantime, so I don't need this anymore.
I am closing the issue. It's great to know how to do it, It might help for another use case.
Have a great day.