Cherry-pick runtime container detection from the hpk/lxcdeploy branch
for the dovecot sysctl block and apply the same pattern to the
port-availability check in deployers.py, and drop both CHATMAIL_NOSYSCTL
and CHATMAIL_NOPORTCHECK from the container startup script and
Dockerfile; the code now self-detects the context.
Add container-based deployment as an alternative to bare-metal pyinfra.
- systemd inside container reusing the existing deployer infrastructure
- chatmail-init.sh runs `cmdeploy run --ssh-host @local` on first boot,
so the container self-deploys using the same code path as bare-metal
- Config via MAIL_DOMAIN env var (simple) or mounted chatmail.ini (advanced)
- External TLS support via TLS_EXTERNAL_CERT_AND_KEY for reverse proxy setups
- Image version tracking in /etc/chatmail-image-version for upgrade detection
- .git/ excluded, but version file mocked so git revparse still works
- Health check verifies postfix, dovecot, and nginx are listening
Files added:
- docker/chatmail_relay.dockerfile: multi-stage build (build + runtime)
- docker/chatmail-init.sh: first-boot deployment script
- docker/chatmail-init.service: systemd unit for init script
- docker/entrypoint.sh: container entrypoint (starts systemd)
- docker/healthcheck.sh: container health check
- docker/docker-compose.yaml: main compose config
- docker/docker-compose.ci.yaml: CI override (uses GHCR image)
- docker/docker-compose.override.yaml.example: customization template
- docker/build.sh: helper script
- doc/source/docker.rst: documentation
- .dockerignore: build context filter