The container runs as uid 10001, compose mounts a file secret with the host's
ownership and mode, and the setup instructions said to chmod 600 a key owned by
the operator. So a deployment built exactly as documented could not open its own
key, and ssh reports that as "Permission denied (publickey,password)" - the same
thing a devbox that rejected the key says. The operator is sent to the far end
to debug a file on this one.
The key is checked before connecting, with the uid this runs as, the file's
ownership and mode, and the chown that fixes it. The setup does the chown now,
and says why it is not optional.
The uid is pinned in the Dockerfile with an explicit gid rather than whatever
useradd picks, because it is now a number written in the README that operators
chown to. A test holds the two together: a uid that moved between them would
produce this exact failure with the documentation insisting it was handled.
The cycle stops rather than alerting. A file on this machine is not a finding
about that one, and no heartbeat goes out - a guard that cannot use its key is
not watching, which is what the dead-man's switch exists to report.
branderson
f92ef81250