"Choose an E-mail address not presently associated with any Gerrit account (can be a "+" extension or sub-inbox as long as the address verbatim isn't in use yet). Create an UbuntuOne account for that address. Log into the review.opendev.org WebUI with that UbuntuOne ID (browser account containers are useful here so you don't have to log out of your normal account). Generate an SSH keypair and upload the public part to the new Gerrit account. Use zuul-client to encrypt the private part and add that to your project configuration: https://docs.opendev.org/opendev/infra-manual/latest/drivers.html#using-secrets"

From https://review.opendev.org/c/openstack/project-config/+/912904