Files
hq/03-DESIGN/01-to-be
jschoubben eab4598494 ADR 0033: a router is scenery, not a node
ADR 0016 makes a lab node a virtual machine, and its reasoning is
fidelity: a node boots a stock image and runs the real install, so it has
to be a real machine or the thing under test is not the thing that ships.

That reasoning does not reach a router. Nothing under test runs on one, it
holds no identity, the mesh never installs anything on it, and no assertion
is ever made about its internals. It exists so packets behave the way they
behave in the world, which is the definition of scenery.

So a router is a system container. What it must reproduce is kernel
behaviour — translation, connection tracking, filtering, forwarding — and a
container has the same kernel.

Verified before deciding rather than assumed. In a plain unprivileged
container: ip_forward and ipv6 forwarding both settable, nftables
masquerade accepted and listed back, and the conntrack timeouts that
mapping_ttl depends on both writable. No privileged mode, no nesting, no
capability grants.

Rejected letting the hypervisor provide NAT, on a stronger ground than
speed: it makes the lab provide what the declaration is supposed to own,
and it cannot express a mapping that expires, a gateway that refuses to
forward, or policy between siblings. The model would shrink to fit the
tool.

The distinction is now load-bearing and has to stay legible: node means
something under test, scenery means something that makes the test real. If
the mesh ever installs anything on a router, it has become a node and this
record no longer covers it.
2026-08-24 01:28:08 +02:00
..

03-DESIGN / 01-to-be

The mesh being built toward. Every statement here traces to a record in 02-DECISIONS/; nothing arrives by drafting.

A document here describes an intention. What currently runs is in 00-as-is/, and the two are never merged — when something ships, the as-is document is written and this one's status becomes implemented.

Document Covers Rests on
00-work-breakdown.md How the decomposition gets built, in what order, and where a human must look ADR 0015
01-end-to-end-testing.md The lab: a real mesh a change can be run against before it reaches nodes ADR 0016, 0029
02-scenario-declaration.md What a scenario declares — the underlay, and what to place on it ADR 0031
03-scenario-lifecycle.md What happens to a scenario — raise, snapshot, restore, move, destroy ADR 0032
04-lab-installation.md Getting the lab onto a clean machine, and why it verifies capability rather than installation ADR 0008

Not yet written

  • The eight bounded contexts. ADR 0015 decides the decomposition; the per-context specifications do not exist yet. The work breakdown says in what order they are needed.
  • Domain grouping outside the core. ADR 0017 settles the principle and explicitly does not settle the domain list. That is a research effort, not a design document, until it concludes.