[cloud-init] change on how DHCP leases are scanned to fetch VR address

[Marc-Aurèle Brothier <ma...@exoscale.ch>]

Hi all,

I pushed a PR for cloud-init to change the way the DHCP leases are scanned
to retrieve the VR ip address. Currently it does scan the lease files in
reverse time order (newest file first) to get the VR address and if that
address does not work, it falls back on the default gateway address.

My change is to scan the DHCP lease in alphabetical order of the iterface
names, retrieving all potential address from those file and iterating among
them in the same order to find the VR address, with the latest entry on the
default gateway address.
This is to overcomes issue when additional interfaces are added to the VM
which are also configured with a DHCP server which is not part of
cloudstack. In the current situtation, cloud-init would try to use the
address from that newest interface.

Does that sound like a good change to everyone? Or would it break, slow
down, your current VM boot process ?

https://code.launchpad.net/~ma-brothier/cloud-init/+git/cloud-init/+merge/336145

Cheers,
Marc-Aurèle

Re: [cloud-init] change on how DHCP leases are scanned to fetch VR address

[Nux! <nu...@li.nux.ro>]

Also interested as the CentOS project is about to patch their cloud-init with this:
http://li.nux.ro/download/nux/tmp/cloud-init7/0050-cloudstack-dhcp-lease-file.patch

Might as well save them the trouble and go directly for Marc's patch.

--
Sent from the Delta quadrant using Borg technology!

Nux!
www.nux.ro

----- Original Message -----
> From: "Marc-Aurèle Brothier" <ma...@exoscale.ch>
> To: "dev" <de...@cloudstack.apache.org>
> Sent: Tuesday, 16 January, 2018 13:43:58
> Subject: [cloud-init] change on how DHCP leases are scanned to fetch VR address

> Hi all,
> 
> I pushed a PR for cloud-init to change the way the DHCP leases are scanned
> to retrieve the VR ip address. Currently it does scan the lease files in
> reverse time order (newest file first) to get the VR address and if that
> address does not work, it falls back on the default gateway address.
> 
> My change is to scan the DHCP lease in alphabetical order of the iterface
> names, retrieving all potential address from those file and iterating among
> them in the same order to find the VR address, with the latest entry on the
> default gateway address.
> This is to overcomes issue when additional interfaces are added to the VM
> which are also configured with a DHCP server which is not part of
> cloudstack. In the current situtation, cloud-init would try to use the
> address from that newest interface.
> 
> Does that sound like a good change to everyone? Or would it break, slow
> down, your current VM boot process ?
> 
> https://code.launchpad.net/~ma-brothier/cloud-init/+git/cloud-init/+merge/336145
> 
> Cheers,
> Marc-Aurèle