Group 2 is resolved: containers resolve, nothing is copied, a route's name says where it arrives

Issue 110's cause was not the filter: the runtime had never been told, and the resolver dropped a query arriving on a bridge. ADR 0148 step 3 landed once it did (109, 151 resolved). ADR 0151 composes a route's internal name under the serving node and drops the suffixed alias (139, 157 resolved). Design 08 amended; a fact in 0148 corrected.
2026-09-30 14:56:43 +02:00
parent 846c1f85f2
commit 04c9500b5b
10 changed files with 247 additions and 19 deletions
@@ -103,6 +103,13 @@ reintroduces 109 and 135 — silently, and on a live mesh, which is exactly how
   ([issue 110](../04-ISSUES/110-a-container-on-the-runtimes-own-network-cannot-reach-the-resolver/00-report.md));
   and on two of four machines the resolver binds loopback only, so the runtime hands containers a
   public resolver instead. Both are prerequisites, not related work.
+
+   > **Progressive insight — 2026-09-30, later the same day. The loopback claim was wrong.** The
+   > resolver bound the private address on all four machines; on two the runtime had never been told
+   > to use it, and on all four the resolver discarded a query that arrived on the runtime's bridge.
+   > The step stands; the facts under it were those. Both fixed the same day
+   > ([issue 110's resolution](../04-ISSUES/110-a-container-on-the-runtimes-own-network-cannot-reach-the-resolver/01-resolution.md)),
+   > and step 3 landed after them.
 2. **The runtime is told which resolver to use, per machine, as a file** — not per container as a
   creation-time argument, or the resolver's address is back in every container's identity and the
   problem has only got smaller.
@@ -0,0 +1,99 @@
+---
+topic: the tiers
+status: accepted
+date: 2026-09-30
+deciders: jochen
+reconstructed: false
+extends: 02-DECISIONS/0066-public-routing-is-name-agnostic.md
+---
+
+# 151. A route's internal name is composed under the node that serves it
+
+## Context
+
+A module that requires a route is given two names from one label: a public one, `<label>.<public
+domain>`, and an internal one, `<label>.<node>.internal`
+([ADR 0138](0138-an-assignment-binds-an-endpoint-and-says-how-far-it-reaches.md)). Both were composed
+from the node the module runs on.
+
+The two are answered differently. The public name is published into every machine's roster at the
+address of the node whose proxy serves it ([ADR 0066](0066-public-routing-is-name-agnostic.md)), so
+it reaches the proxy from anywhere in the mesh. The internal name is answered by every machine's
+resolver as *anything under a node's name goes to that node*
+([design 08 §2](../03-DESIGN/01-to-be/08-connectivity.md)) — the node it was composed from, which is
+the consumer's. Where the proxy runs on another machine, that name sends a client to a machine with
+nothing listening, while the public name works
+([issue 139](../04-ISSUES/139-an-internal-route-name-resolves-to-the-consumers-node/00-report.md)).
+Every route on this mesh today is served beside its module, so it has not been seen; `route` is
+provided mesh-wide precisely so that stops being true.
+
+Beside it, the roster gave every routed name a second entry with the mesh's suffix appended —
+`<name>.<public domain>.internal` — because it composed a full name for every entry as it does for a
+machine. That name resolved on every machine, was served by nothing, and was refused by the proxy at
+the handshake; the first three names tried while reproducing an unrelated issue were those, and the
+evidence pointed at a regression that had not happened
+([issue 157](../04-ISSUES/157-a-routed-names-internal-alias-is-served-by-nothing/00-report.md)).
+
+## Considered Options
+
+**1. Keep the consumer's name and publish it at the serving node's address**, as the public name is.
+The name stays `<label>.<consumer>.internal` and an exact roster entry overrides the wildcard.
+Rejected: it makes `<x>.<node>.internal` mean *goes to that node* except when it does not, which is
+the one rule the resolver design states; it needs an entry per route where the wildcard needed none;
+and which of an exact entry and a wildcard a resolver answers first is the resolver's business, which
+the mesh deliberately does not know.
+
+**2. A proxy on every machine, so the serving node is always the consumer's.** Rejected for this
+question: it is a different decision about what `route` is — a node-scoped seat with a mesh-wide
+fallback — and this mesh runs one proxy on the hub today. Whatever is decided there, a route served
+from another machine must have a name that reaches it.
+
+**3. Compose the internal name under the node that serves the route.** Chosen.
+
+## Decision
+
+**A route's internal name is `<label>.<serving node>.internal` — composed under the node whose proxy
+answers the route, which is the machine the request arrives at.** The public name is unchanged:
+`<label>.<public domain>` of the node the module runs on, which is where the operator put it.
+
+Where the proxy runs beside the module — every route on this mesh today — the two nodes are one and
+nothing changes. Where it does not, the name says where the request goes, which is what a name under
+a node's name has always meant.
+
+**A routed name has no mesh form.** The roster publishes it as itself, once, at the serving node's
+address. Only a machine has a bare name beside its full one.
+
+What certifies the internal name is unchanged by this: the proxy that terminates it obtains a
+certificate from the mesh's authority for the names it is given, and it is given this one.
+
+Taken on the operator's standing instruction to answer the open design questions in the work order.
+
+## How this is checked
+
+- **Composition.** A controller test contributes a route from a module on one node to a proxy offered
+  from another, gathered the way the controller gathers a consumer's contribution for a provider on
+  another machine, and asserts the internal name carries the serving node.
+- **Publication.** A controller test renders a roster with a machine and a routed name and asserts
+  the routed name appears as itself, once, and never with the suffix appended.
+- **On the mesh.** After the change no machine's roster carries a `<domain>.internal` entry, and a
+  route's internal name still answers from a container with a certificate from the mesh's authority.
+
+## Consequences
+
+- **A route served from another machine now has a usable internal name.** The first module assigned
+  that way will resolve, where before it would have resolved to the wrong machine with no error.
+- **The internal name of a route can change when its proxy moves.** A route re-homed from one proxy
+  to another gets a new internal name, as the design's rule implies; clients that dialled the old one
+  reach the old machine. The public name does not move with the proxy and is the stable one.
+- **The roster is one line shorter per routed name**, and a person reading a hosts file no longer
+  finds names that resolve to a refusal.
+- **Issue 139's second question — a per-node route holder — is left open**, and is a decision about
+  what a seat is rather than about a name.
+
+## References
+
+- [issue 139](../04-ISSUES/139-an-internal-route-name-resolves-to-the-consumers-node/00-report.md) — the question
+- [issue 157](../04-ISSUES/157-a-routed-names-internal-alias-is-served-by-nothing/00-report.md) — the alias
+- [ADR 0066](0066-public-routing-is-name-agnostic.md) — routed names propagate mesh-wide; extended here
+- [ADR 0138](0138-an-assignment-binds-an-endpoint-and-says-how-far-it-reaches.md) — how the two names are composed and how far each reaches
+- [design 08 §2](../03-DESIGN/01-to-be/08-connectivity.md) — anything under a node's name goes to that node
@@ -200,6 +200,7 @@ python3 00-META/checks/index.py            fail if stale
 - **0109** — [A package registry seat is one per ecosystem, not one for all of them](0109-a-package-registry-seat-is-one-per-ecosystem.md)
 - **0126** — [A module declares its own seats; the mesh reserves its own](0126-a-module-declares-its-own-seats.md)
 - **0148** — [The mesh's names are resolved, not copied into every container](0148-the-meshs-names-are-resolved-not-copied-into-containers.md)
+- **0151** — [A route's internal name is composed under the node that serves it](0151-a-routes-internal-name-is-composed-under-the-node-that-serves-it.md)

 ### What runs on them, and how it gets there