The v2.18 image's entrypoint runs the setup wizard on first boot. Without
the SEMAPHORE_ADMIN_* variables it prompts on stdin, fails with 'Username
cannot be empty', and the container exits — leading to a crash loop.
Set:
SEMAPHORE_ADMIN=admin
SEMAPHORE_ADMIN_NAME=Administrator
SEMAPHORE_ADMIN_EMAIL=admin@local.mk-labs.cloud
SEMAPHORE_ADMIN_PASSWORD={{ vault_semaphore_admin_password }}
SEMAPHORE_PLAYBOOK_PATH=/var/lib/semaphore/playbooks
The env-var bootstrap path is stable in v2.x; only the legacy
'semaphore user add' CLI invocation was unreliable. Drop the manual
user-add step from the README.