`hermes gateway migrate --multiplex` ran its one fallible step LAST (install +
start the default gateway) with nothing around it. On a fleet whose secondary
ran a system unit as root (#110850) that step raised, leaving the flag on, the
secondary's unit removed and no gateway anywhere, and the re-run hit the
"already multiplexing (flag on)" short-circuit over an empty fleet.
- apply_migration(): the default bring-up runs inside a rollback. On failure the
manifest written before the first destructive step restores the flag and
reinstalls every recorded per-profile gateway with its recorded User=.
- MigrationPlan.interrupted: flag on + manifest present + no live default
gateway is a half-applied migration, not "already multiplexed"; the re-run
resumes from the manifest (target manager and User= read from it, since the
units themselves are gone) instead of refusing. Flag off + leftover manifest
refuses to overwrite it and points at --standalone.
- ProfileGateway.services records EVERY installed unit (user and system) and the
manifest carries them; apply stops/uninstalls all of them and rollback
reinstalls all of them, so a second owner is never left live beside the
multiplexer. The unattended hook treats a two-unit profile as an ambiguous
topology and refuses (review finding on #110205).
- gateway_identity(): an unresolvable User= on a system unit stays None instead
of borrowing the profile directory's owner; the unattended hook treats the
unknown principal as a boundary (review finding on #110205).
- auto_migration_opted_out(): reads the effective config (load_config_readonly
under the default home), so a managed `false` wins over a user `true` and a
YAML string "false" is an opt-out, not a truthy value (review finding on
#110205).
Builds on KoNit-K's #110854 (run_as_user threaded through install, preserved
from the removed system unit).
Reshape the two salvaged commits onto current main (#109954):
- Move the boundary guard out of the gateway_migrate facade into a new sibling
hermes_cli/gateway_migrate_guards.py as a table of guard functions
(_AUTO_MIGRATION_GUARDS: service domain, UNIX user, HERMES_HOME tree) plus the
identity resolver. The facade grows by ~20 lines only (uid/runtime_home on
ProfileGateway, one seam, the hook wiring).
- Compare uids, not strings: live pid owner via /proc (ps fallback only on
macOS, where /proc does not exist), else the system unit's User= via
_read_systemd_user_from_unit (root when absent), else the home directory's
owner. None means unknown and never blocks.
- The home-tree guard reads the HERMES_HOME the installed unit pins, not the
directory the plan enumerated: that is where the gateway really runs and is
exactly the "stale copies under profiles/" shape from the report.
- When the default is detached, a service-managed secondary is a different
domain for the AUTO path (it must not elect the secondary's manager); the
explicit command keeps electing it as before.
- The explicit command surfaces the same findings as notices (dry run shows
them) and is never blocked by them; only the update hook refuses.
- Rename the opt-out key to gateway.auto_multiplex_migration (nested only, no
top-level alias) and read it before a plan is built, so false prints nothing
and touches nothing. The explicit command ignores it.
- Tests trimmed to the invariants: one parametrized boundary test that exercises
the real hook end to end (refuses, touches nothing, dry run shows the notice),
one "same user / same scope still migrates" control, one opt-out test.
- Docs: boundary table + renamed opt-out section in multi-profile-gateways.md;
one line in hermes_cli/AGENTS.md.
Co-authored-by: KoNit-K <124019182+KoNit-K@users.noreply.github.com>
Co-authored-by: Athena <athena@olympus.local>
teknium1