openbao runs as a DynamicUser, so the uid that has to open the token
store is allocated by the container's PID 1 and cannot be named by a
host unit — the store was created root-owned 0700 and the seal could
never read it. The provisioning unit moves inside the container and
hands the sqlite store over by group; the host keeps only the mkdir the
bind mount needs, create-only so a reboot does not re-impose 0700.
Two further layers blocked the same start, both measured while fixing
this one:
- DynamicUser implies ProtectSystem=strict (systemd.exec(5)), so the
bind mount was read-only to openbao however it was owned, and the
pkcs11 library opens its store read-write. ReadWritePaths= is
required and was absent.
- allowedDevices renders DeviceAllow= and nothing else, and nspawn
builds its own /dev as a fixed tmpfs and cannot create device nodes
— verified against a live container, whose /dev holds no host
devices at all. /dev/tpmrm0 was therefore absent inside swarm-bao,
not merely unpermitted. It is now bound in.
Whether openbao's dynamic uid may *open* that node is a third question:
the tss gid is dynamically allocated, so no name or number means the
same thing on both sides of the boundary. Filed separately rather than
guessed at here.
The two module-eval cases that asserted the unit on the host now assert
it in the container and absent from the host, and two new cases pin the
device bind and the write access — each was individually valid and
collectively required, which is the state no assertion catches. Both
new cases select with `or [ ]`: mutation-testing them showed that a bare
select aborts the run with a nix trace instead of failing the case by
name, which also hid the second failure behind the first.
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