Is there a tool which supports headless LXD clustering for a CI environment or when there is a large number of nodes?
Currently, not that I’m aware of. You could certainly arrange something with Ansible or similar tool to automatically join the LXD nodes using
lxd init --preseed.
We’re currently hiring for a role on the LXD team which will have our team take over the Juju charm for LXD and LXD cluster and will allow using that tool to deploy large clusters on hardware or in the cloud.