Replace the two-function find_relay_image / _find_relay_image pair
with Incus.find_image(aliases), which returns the first alias
that exists in the local image store, or None.
Container.launch() passes [RELAY_IMAGE_ALIAS, BASE_IMAGE_ALIAS]
and ensure_base_image() passes [BASE_IMAGE_ALIAS].
Add cmdeploy "lxc-test" command to run cmdeploy against local containers,
with supplementary lxc-start, lxc-stop and lxc-status subcommands.
See doc/source/lxc.rst for full documentation including prerequisites,
DNS setup, TLS handling, DNS-free testing, and known limitations.
Apart from adding lxc-specific docs, tests, and implementation files in the cmdeploy/lxc directory,
this PR adds the --ssh-config option to cmdeploy run/dns/status/test commands and pyinfra invocations,
and also to sshexec (Execnet) handling. This allows for the host to need no DNS entries for a relay,
and route all resolution through ssh-config. This is used by the "lxc-test" command, which performs
a completely local setup -- again, see docs for more details.
While working on DNS/SSH things i also unified all zone-file handling
to use actual BIND format as it is easy enough to parse back.
