jochen
d169f9d8cd
- Secrets follow ADR 0085 as amended: a module's own secret is a provision the controller mints and the vault records. The previous commit had that backwards. Whether the vault should generate instead is recorded as an open question, not decided. - A directory's contract is owner and mode only. The persistence flag was the keep flag ADR 0030 refused; a directory is kept while it holds anything, and disposable data is a named volume (0107). - An operator's shared data stays an access (ADR 0051), which rejected an operator-owned directory. Only where its path is written moves to the assignment. - The records it changes on acceptance are named: 0051, 0091, 0046 (settings keyed by instance), 0084 (a provider is a node and an instance), and the glossary, which gains its new words only when the record is accepted. - How it is checked covers every stated rule. Container-side paths are no longer flagged by the host-path rule, and code fallbacks are covered. - Provisions are what other modules provide. A seat's occupant is not listed as one, and the vault is not described as selectable per assignment. - 'Control plane' becomes 'controller'. The provider count is ten of eleven, not eleven of twelve.
3.9 KiB
status, opened, located-in, fixed-by, amended-design
| status | opened | located-in | fixed-by | amended-design |
|---|---|---|---|---|
| open | 2026-09-25 |
118 — 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.
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?