jochen
e387c4bd0e
The fact-check found mailu, whose user is its mailbox, so 0114 rotates over two credentials rather than two logins, the adapter choosing what a credential is. Also: minio keeps non-empty buckets; five backends take their admin credential only at first init, so single-party rotation is staged; postgres ownership moves to a non-login role; the harness keys by consumer; rotation state lives with the vault. Consistency fixes across 0110-0113, 26 and 27; issue 103 resolved by mesh-host PR #22.
4.3 KiB
status, opened, located-in, fixed-by, amended-design
| status | opened | located-in | fixed-by | amended-design | ||
|---|---|---|---|---|---|---|
| located | 2026-09-25 |
|
119 — A module definition decides where its files live on the machine
What was observed
A review of where module code reads its files turned up a cross-cutting pattern. Every module
definition in the catalogue chooses, in its own manifest, where on the machine its files live.
Counted on the catalogue's main, 2026-09-25:
| where in the definition | host-path strings |
|---|---|
| directory and file resources | 257 |
| container mounts, host side | 230 |
| own secrets | 78 |
| bindings | 53 |
| env-files | 50 |
| secrets | 35 |
| container environment | 28 |
| accesses | 21 |
| receives, grants | 24 |
| everything else | 13 |
789 host-path strings in 70 of the 71 definitions. Mounts are checked: a container may not mount a path its module never declared (ADR 0091). Nothing checks the same path where it is retyped as a value: an environment variable, an env-file line, a literal in module code.
Where that has already gone wrong
- A provider that would provision nobody, silently. One DNS provider mounts its grants directory at a short path inside its container, then tells its provisioner to read the contributions file at the host path, which does not exist in there. Nothing requires the provision today, so it has not failed yet. When a consumer arrives, it will get no record, and nobody will be told.
- The mesh's own wire carries host paths into containers. Each contribution names its consumer's credential as "the file on this machine holding that consumer's credential", a host path computed from the provider's grants directory. So every provider has to mount that directory at the identical path, or it cannot read what it was given. Ten of the eleven providers with a grants directory do. It is a convention nothing states or checks, and the eleventh is the provider above.
- The warning that would have caught it is lost in the SDK. The controller always writes the contributions file, even when empty, so a provider can tell "nothing asked" from "never written". The SDK's reconcile loop treats an unreadable file as empty, and logs nothing.
- Code carries copies with nothing checking them. Several modules default a path in code when an environment variable is unset. Five of those defaults disagree with the value their own manifest sets. One of them is a host path used inside a container that does not mount it.
And a module cannot be assigned to one node twice
Everything that identifies a running module is keyed by the module's name: its directories, its container names, the login it presents to a provider, its broker account. Two assignments of one module to one node would share every one of them. Assigning the same application twice is an ordinary need: production beside staging, one site per customer, two instances of one service configured differently, two stores of one engine.
ADR 0112, which answers this report, declines that need rather than meeting it. A module is assigned at most once to a node, because every identity in the mesh is already a module on a node. The cases above become different modules, or the same module on different machines.
Why it matters beyond this instance
A definition that names machine paths is not portable between nodes. It cannot follow data onto a second disk, or onto a machine being adopted with its data already in place, without editing the module. It cannot run twice on one node. It keeps every path in two or three places with nothing checking that they agree. The defects above are what that allows, and each was found by reading, not by any check.
Open questions
- Should a definition name any host path at all, or should every location come from the assignment and the mesh?
- If a directory is something a module requires rather than declares, what is its contract: ownership, mode, whether it is kept when the module goes?
- What identifies an assignment, if a module may be assigned to one node more than once?
- What would the contributions file carry instead of host paths, so a provider needs no identical-path mount?