ifupdown2 can invoke scripts under /etc/network/if-*.d/*
in the required order with the required environment variables.
This patch includes fixes to execute these scripts.
The following attributes in /etc/network/ifupdown2/ifupdown.conf
can influence the execution behaviour of python-addon modules
and /etc/network/if-*.d/*
<ifupdown.conf>
addon_syntax_check=0
addon_scripts_support=1
addon_python_modules_support=1
</ifupdown.conf>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
ifupdown2 code was one level deeper because ifupdown2 initially
had ifupdown2 and ifupdown2-addons as two separate packages.
Since they were combined into one package, it makes sense to
move all combined code under the top level directory
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
