jschoubben
702efca6bb
HQ held only the to-be. Every reader had to already know the system the decisions were about, and an as-is claim had nowhere to live except inside an intention. Adds 02-DESIGN/00-as-is — eleven documents written from the implementation and the operational record, not from intent, including the parts nobody would choose again. The two existing designs move under 01-to-be. Layers are declared in frontmatter and never mix: a design that ships does not move, its as-is counterpart is written, and both stand. Back-fills adr/0001-0014 for decisions taken in implementation and never recorded — the broker, the module abstraction, the mesh database, managed files, provisioning, migrations, the workspace removal, failing loudly, the constitution, application placement, linking, the employee model, the artifact, the three silos. Each marked reconstructed, dated from the history, and citing the evidence it was recovered from. The two existing records renumber to 0015 and 0016 so the ledger runs oldest first; 0017 extends 0015 to modules outside the core, principle only — the domain list is deliberately not invented here. how-we-build.md becomes the source of the mesh constitution, with a sync playbook, so the enforced copy stops being the only one that is true. Process becomes explicit: five playbooks, eight thin skills that defer to them, a repository map, and AGENTS.md with CLAUDE.md as its include. The five Observations become 04-ISSUES 001-005 where they can be owned and closed. 006 is new and uncomfortable: HQ is not indexed into the knowledge base. That claim is what decision 27 rests on, it was never checked, and the README now says so instead of repeating it. Also corrects the ADR index into something generated, the "02-DESIGN is empty" claim, the VISION.md pointer that did not survive the repo split, and a note asserting the symlink rule was contradicted — it was a misreading; the rule forbids hand-made links, the installer links by design.
2.7 KiB
status, date, deciders, reconstructed
| status | date | deciders | reconstructed |
|---|---|---|---|
| accepted | 2026-07-10 | jochen | true |
11. The installer owns linking; nothing else creates a symlink
Reconstructed after the fact from the evidence cited below. The incident that earned the rule predates the record, and its date is not established here.
Context
A service's definition lives in the module catalogue; its runtime directory and persistent data live outside it. The mesh connects the two by linking the definition into the runtime location — deliberately, so that runtime state and source stay separate while the running service reads a current definition.
A link is also the easiest thing in the world to create by hand while fixing something, and a container engine resolves a bind mount through it. A hand-made link pointed a volume somewhere it should not have, and production data was lost.
Considered options
- Copy instead of linking. Rejected. A copy goes stale silently, which trades data loss for a service running a definition nobody can find.
- Allow links, document the hazard. Rejected. The hazard is not knowable at the moment of the mistake — the link looks right and the resolution happens inside the container engine.
- One component owns linking; everyone else is forbidden. Chosen.
Decision
The installer creates and repairs every link the mesh needs. It reconciles them: a missing link is created, a stale one is repointed, and a real file found where a link belongs is adopted into the node's override location and replaced.
Nothing else creates a symlink — not a hook, not a fix, not an agent, not a person debugging. The prohibition is absolute because the judgement required to make a safe exception is exactly the judgement that was not available at the moment it mattered.
Consequences
- The class of failure is closed, at the cost of a rule that reads as arbitrary to anyone who has not seen the incident. That is why it is recorded here rather than only asserted.
- Links become reconcilable state rather than incidental filesystem facts.
- The rule is stated for humans and agents and is enforced by convention, not mechanism. A check does not exist.
- The rule is regularly misread as "the mesh does not use symlinks", which is false and makes the design documentation look self-contradictory. It uses them; it centralises who may make them.
References
- Recorded as a non-negotiable in the governed constitution page, §2: "Symlinks to repos or service directories have caused production data loss via Docker volume path resolution. The installer handles all linking. Never create symlinks manually."
- Knowledge base:
services— the reconciliation behaviour, including adoption of real files.