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Launching a server with a configuration drive

Background: OpenStack metadata discovery

OpenStack Compute uses metadata to inject custom configurations to servers on boot. You can add custom scripts, install packages, and add SSH keys to the servers using metadata.

By default, metadata discovery in Cleura Cloud uses an HTTP data source that booting servers connect to. Sometimes this is undesirable or — for specific server/networking configurations — unreliable. Under those circumstances, you can use an alternate configuration source.

Store metadata on a configuration drive

A configuration drive (config drive) is a read-only virtual drive that is attached to a server during boot. The server can then mount the drive and read files from it. Configuration drives are used as a data source for cloud-init.

Enable the configuration drive on server creation (openstack CLI)

To enable the configuration drive, you need to pass the parameter --use-config-drive to the openstack server create command.

In the following example, replace the image, flavor, keypair, and network reference, as well as the server name, to match your desired configuration.

openstack server create \
  --use-config-drive \
  --image "Ubuntu 20.04 Focal Fossa" \
  --flavor b.1c2gb \
  --keypair mykey
  --nic net-id=3a747038-ee59-404c-973d-5f795e8ebb73 \

Once the server launches, you can monitor its configuration process by monitoring the server console log:

openstack console log show myserver

Last update: 2022-11-29
Created: 2022-04-27
Authors: Florian Haas, Namrata Sitlani