Hello, This is very true and good feedback, something that nags me everytime I think about it. Having a shared storage and using rbd images backend and still needing SSH between compute nodes. I'm hoping to have some time helping out to clear that up in the libvirt driver. Best regards ________________________________ From: Thomas Goirand <zigo@debian.org> Sent: Monday, November 23, 2020 1:21:14 PM To: openstack maillist Subject: Re: [nova][tripleo][rpm-packaging][kolla][puppet][debian][osa] Nova enforces that no DB credentials are allowed for the nova-compute service On 11/23/20 11:42 AM, Balázs Gibizer wrote:
On Mon, Nov 23, 2020 at 11:18, Thomas Goirand <zigo@debian.org> wrote:
On 11/23/20 9:30 AM, Tobias Urdin wrote:
Hello,
Just to clarify that this is already possible when using puppet-nova, it's up to the deployment to
make sure the database parameters for the classes is set.
We've been running without database credentials in nova.conf on our compute nodes for years.
Best regards
Tobias
Hi Tobias,
That's not what I'm suggesting.
I'm suggesting that nova-compute code from upstream simply ignores completely anything related to db connection, so we're done with the topic. That is, if nova-compute process having access to the db is the issue we're trying to fix.
Or is it that the security problem is having the db credentials written in a file on the compute node? If so, isn't having hacked root (or nova) access to a compute node already game-over?
What are we trying to secure here? If that's what I'm thinking (ie: some VM code to escape from guest, and potentially the hacker can gain access to the db), then IMO that's not the way to enforce things. It's not the role of upstream Nova to do this apart from a well enough written documentation.
I always understood this as having a goal to limit the attack surface. So if a VM escapes out of the sandbox and access the hypervisor then limit how may other services get compromised outside of the compromised compute host.
Cheers, gibi
In general, I would agree with this. However, because of the way cold migrations are working, nova compute boxes are authenticated between each other through ssh. You'd be limiting access to the db, but someone with nova or root ssh access could destroy all compute nodes. So, like it or not, it's game-over anyways. If you want to fix things, make it so that Nova doesn't require such ssh authentication anymore, because that's more urgent, *THEN* we can revisit this topic. Cheers, Thomas Goirand (zigo)