Today the .channels.yaml file is generated when wildfly-channel is in use to provision a server.
With the introduction of manifest.yaml and installation-config.yaml the plugin should generate these 2 files in target/server/.installation/ to be able to use prospero to update a server provisioned with the plugin.
The PR https://github.com/wildfly-extras/wildfly-channel/pull/109 will expose the API needed to store these 2 files in target/server/.installation