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.
refactor README.rst and architecture file into sphinx doc project, automatically deploying on main merges and PRs.
* add FAQs from https://chatmail.at/relays landing page
* fix links, and streamline postfix/dovecot mentioning
* add linkcheck to CI, fix several links and streamlihne DKIM section while at it
* some streamlining, rename to "overview"
* ci: upload documentation to chatmail.at/doc/relay
* ci: main should be uploaded when docs.yaml changes
* ci: fix typo
* Update .github/workflows/docs-preview.yaml
Co-authored-by: missytake <missytake@systemli.org>
