Merge pull request 'to-be 29: a node has operator accounts, and the mesh owns what lives under a home' (#138) from design/29-a-node-has-operator-accounts into main

2026-09-26 21:53:39 +00:00
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+---
+layer: to-be
+status: proposed
+code: []
+updated: 2026-09-27
+decisions:
+  - 02-DECISIONS/0112-a-module-definition-names-no-node-mesh-or-path.md
+  - 02-DECISIONS/0051-shared-data-is-the-operators.md
+---
+
+# 29 — A node has operator accounts, and the mesh owns what lives under a home
+
+**The mesh models machines but not the people on them.** A node record holds its name, its
+address, its mode — and nothing about *who a person is* on it: `jochens` on novox, `ace` on ace,
+`jochen` on shanks and g14. That username is not incidental. It decides who a file under `~` is
+owned by, who a user service runs as, and — the case that surfaced this — which account `ssh
+<node>` logs in as. The predecessor knew it (its per-node `user:`, and the modules that wrote a
+person's `~/.ssh/config`, `~/.zshrc`, `~/.config`); the mesh, taking those over, kept the machine
+facts and dropped the human one.
+
+Two things are missing, and they are one idea:
+
+## 1. The account is a node fact
+
+A node has one or more **operator accounts**: the human logins on it. At minimum a name; the
+mesh already knows the node and its address, so `<account>@<node>` is then a complete answer to
+"who am I, where." It is the mesh's to hold because everything below is derived from it, and
+because it is exactly the fact that was silently lost — `ssh ace` failed to `ace` because nothing
+in the mesh said ace's account is `ace`.
+
+It is **not** a credential. The account names a login; the key that authorises it is the
+operator's, placed as a secret or an operator-owned file, never minted by the mesh (ADR 0051).
+
+## 2. A resource may live under a home, owned by its account
+
+[ADR 0112](../../02-DECISIONS/0112-a-module-definition-names-no-node-mesh-or-path.md) placed a
+module's *system* data — `<root>/<module>`, owned by the module. It has no analog for the other
+half of the filesystem: the things that belong under a person's home and are owned by that
+person. `~/.ssh/config`, `~/.ssh/config.d/mesh`, `~/.zshrc`, `~/.config/hal` — every one of these
+is a resource the mesh should be able to place and own, resolved against **the account's home**
+rather than a system root, and chowned to **the account** rather than to root or a module uid.
+
+This is the same move as `${dir:…}`, one level over: a resource says `home: <account>` (or names
+an account requirement), and the mesh resolves the home directory and the owning uid on the node
+that account lives on. A module that writes operator config — the eventual replacements for
+`hal/terminal`, `hal/claude-code`, `hal/secrets` — declares its files this way and names no
+`/home/...` path, exactly as a system module now names no `/var/lib` path.
+
+## Why now, and why not yet
+
+**Why it matters:** when HAL retires, the generators that keep `~/.ssh/config`, shell config and
+the operator's `~/.config/hal` current retire with it. Without this, adding a node stops adding
+its ssh alias, and a fresh machine has no operator dotfiles at all — the mesh would run every
+service and leave the human unable to work on the box. The account is also load-bearing for
+correctness already: `ssh <node>` (issue 122's cousin), user-scoped systemd units, and any file a
+person rather than a daemon must own.
+
+**Why not build it reflexively:** it is a real addition to the node model and the resource model,
+and it must be gotten right, not smuggled in beside a firewall fix. Open questions to settle
+first:
+
+- **One account or several per node?** A workstation has one human; a shared box might have more.
+  The model should allow more than one without forcing the common case to name it.
+- **Where the login key lives.** An operator-owned file (ADR 0051) or an accepted secret — never
+  minted. The account fact and the key that authorises it are separate, and only the first is the
+  mesh's to generate.
+- **The boundary with `sshd`.** The `sshd` module (server side) already exists. This is the
+  *client* and *identity* side: the account a node offers, and the home-scoped files an operator
+  needs. They meet at the account but are not the same module.
+- **Multi-operator.** Today there is one human. The model should not assume it, but the first
+  cut may serve one and leave the shape open.
+
+**Not urgent, not blocking.** ssh and dotfiles work today because HAL's generators still run as
+the substrate. This becomes load-bearing in the node-by-node retirement phase, not before — which
+is the right time to build it, once the account model is decided here.
+
+## References
+
+- The gap was found generating `~/.ssh/config` from the *HAL* registry (`hal/terminal`'s
+  postConfigure hook), which the nox mesh has no equivalent for.
+- [ADR 0112](../../02-DECISIONS/0112-a-module-definition-names-no-node-mesh-or-path.md) — the
+  system-path placement this mirrors for home paths.
+- [ADR 0051](../../02-DECISIONS/0051-shared-data-is-the-operators.md) — why the login key stays
+  the operator's, never minted.
@@ -38,6 +38,7 @@ document is written and this one's status becomes `implemented`.
 | [`26-the-seats.md`](26-the-seats.md) | **Proposed.** What a mesh can have one of, who fills each, and a seat's holder answering for the provision it delivers — including the `git` seat a build's source can live on | [ADR 0110](../../02-DECISIONS/0110-a-seat-is-a-module-assignment-from-a-closed-set.md), [ADR 0111](../../02-DECISIONS/0111-a-build-source-is-on-the-git-seat-or-external.md), [ADR 0109](../../02-DECISIONS/0109-a-package-registry-seat-is-one-per-ecosystem.md) |
 | [`27-a-module-requires-the-mesh-resolves.md`](27-a-module-requires-the-mesh-resolves.md) | **Proposed.** One concept for everything a module needs: a requirement with a contract, answered by one of four kinds of provider, resolved at assignment or refused. Retires settings, placeholders, facts and paths in definitions | [ADR 0112](../../02-DECISIONS/0112-a-module-definition-names-no-node-mesh-or-path.md), [ADR 0113](../../02-DECISIONS/0113-the-vault-makes-every-secret.md), [ADR 0114](../../02-DECISIONS/0114-a-shared-credential-rotates-over-two-credentials.md), [ADR 0110](../../02-DECISIONS/0110-a-seat-is-a-module-assignment-from-a-closed-set.md) |
 | [`28-building-the-bus.md`](28-building-the-bus.md) | **Proposed.** The five steps of the bus work in the order their dependencies allow, each ending at a bed — with the surface measured, so no step's size is a guess | [ADR 0116](../../02-DECISIONS/0116-the-bus-is-built-in-five-steps.md), [ADR 0106](../../02-DECISIONS/0106-the-bus-is-nats.md), [ADR 0074](../../02-DECISIONS/0074-the-wire-is-specified-not-the-types.md) |
+| [`29-a-node-has-operator-accounts.md`](29-a-node-has-operator-accounts.md) | **Proposed.** The mesh models machines but not the humans on them: a node gains operator accounts, and a resource may live under a home owned by its account — what would own ~/.ssh, dotfiles and ~/.config when HAL retires | [ADR 0112](../../02-DECISIONS/0112-a-module-definition-names-no-node-mesh-or-path.md), [ADR 0051](../../02-DECISIONS/0051-shared-data-is-the-operators.md) |

 ## Not yet written