The upstream `smallstep/step-ca` image runs as uid 1000. An own-secret lands as
a file the host writes root:root 0600 — the module says only a name and a path,
so there is nowhere to say who must be able to read it — and the container
crash-looped on `permission denied` reading its own root key. The lab got past
it first with `chmod 0644`, which hands the root key to every local user, and
then by running the CA as root, which is worse.
Neither is needed. A module composes its own files, and a `file` resource takes
both a `mode` and an `owner`, with `${secret:name}` reaching the module's own
secrets — the mechanism redis already uses to hand its password to a server
running as 999. So the three pieces of init material are declared as owned
files: still 0600, owned by 1000:1000, and those are what the container mounts.
The raw own-secret files stay where they were. Nothing mounts them now; they are
how the secret comes to exist on the machine, and the host is the only thing
that reads them. Same shape as redis's `default.secret`.
Verified against the real code rather than by inspection: mesh-control attaches
the sealed value to each of the three resources and keeps `owner` and `mode`
(`sealedFor` + `intoFile` over this manifest), and mesh-host parses `owner` on a
sealed-substituted file and lands it 0600 owned by 1000:1000 (`applyFile`).
jschoubben
d9fbc72565