Is there a way to have some default user data/config drive when launching a VM, I.e NOT manually specified by the user?

user432024

8/10/24, 6:23 PM

Hi I'm running a private Openstack and I know when we create VM we can pass a config drive to add additional configs to the VM.

But there's some configs we want to standardize across all VMs that users create and not have to rely on user to pass the config drive.

pre-built images that have this config, which relies on someone taking care of building these ISOs.
Have Openstack inject default configs through config drive/userdata/meta data?

I'm hoping #2 exists :)

1 + 3

openstack

eblock

8/11/24, 9:55 AM

If those defaults apply to all VMs, the best option is to add those configs to your golden image(s). Additional user-defined data can be injected via user-data (optionally via config-drive) as you already stated. To create your golden image just boot a VM, make your changes and upload it to the glance store. You don't need to maintain and build ISOs.

user432024

8/11/24, 1:09 PM

So no using vendor data or anything like that?

eblock

8/11/24, 1:52 PM

It really depends on your actualy requirements, you have to decide if you need vendor-data or not. Tbh, I've never used vendor-data, only user-data via metadata service or config-drive, that's sufficient for our use-cases. We create golden images with some default settings (for example having salt-minion enabled, nameservers and what not) so the instances come up with a hostname and IP, and to finish the VM configs we use salt. For provider networks we use config-drive, otherwise the metadata service is sufficient.

Score:0

Server

Fernando Rosado

8/24/24, 7:55 AM

When I create a new image I set this kind of parameters using glance as property value :

 $ glance image-create --name "CentOS 7.9" \
 --file /mnt/backup/centos-7.9-cloud.raw\
 --disk-format raw \ 
 --container-format bare \
 --property hw_scsi_model=virtio-scsi \
 --property hw_disk_bus=scsi \
 --property hw_qemu_guest_agent=yes \
 --property os_require_quiesce=yes \
 --visibility public \
 --progress

In fact, I have problems when instead of creating a VM from an image, I try to generate from a Snapshot. I also tried to add those properties at "flavor" level, but appears it is not working.

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EN: Is there a way to have some default user data/config drive when launching a VM, I.e NOT manually specified by the user?

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