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Re: RHEL / CentOS - interfaces.template


On 02/14/2012 06:48 PM, Scott Moser wrote:
> On Tue, 14 Feb 2012, Leandro Reox wrote:
>> Hi guys,
>> Anyone already implemented networking injection to RHEL systems acting as a
>> guest ? If no any plans to make it to Essex final ?
> Before we go down the road of trying to write system network configuration
> scripts for each potential guest OS, I'd suggest that its would be better
> to either:
>  a.) just accept that 'interfaces' is the openstack format and guests
>      should need to read that.
>  b.) create a OS agnostic interface configuration format.
> While you may be looking at my email address and assuming that I think 'a'
> is the right answer only to make it harder for anyone else.
> However, the reason I dislike the current solution (or going down a path
> of implementing population mechanisms for other operating systems) is
>  1.) you cannot possibly support all possible operating systems
>  2.) injecting files assumes host OS knowledge (or guestfs knowledge) of
>      the guest filesystem
>  3.) specific files indicates that the host can somehow determine which
>      format the guest is expecting (or also unacceptable, only allowing
>      this configuration for one OS per cloud).
>  4.) injecting files via overwriting them is lossy and possibly
>      destructive to a guest (imagine other vpn routes inserted there or
>      something else more advanced).
> I would *much* rather there be a "openstack networking configuration file
> format" that was put into config_drive if dhcp was not sufficient.
> Then, the guests are just made to read that information that is in a
> standard, easily documetable format and respond accordingly.

I have to agree with this.

Ideally openstack would not be polluted with all the
vagaries of guest network configuration.
Though if --flat_injected is a required and common case,
then perhaps in the short term it would be worth adding something
like the griddynamics patch to support the two most common linux formats?
Until now, we've not considered this a priority.


This issue is already tracked at:

The Red Hat openstack packages do not have any extra support in this regard
(especially since this is a guest issue). All file injection patches supporting
Red Hat (derived) _hosts_, including libguestfs support, are upstream in Essex.

The netcf lib looks interesting. Perhaps it could leverage libguestfs
(already integrated) to maximise the types and configurations of guests it could target?

Points 1 & 2 above are more general and apply to ssh key injection also I think.
libguestfs helps a lot to abstract those guest specific issues away.


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