0164: a setting names the file it lands in (issue 198's leak between one module's files); 190 notes the fourth machine now has the resolver

2026-10-02 12:23:28 +02:00
parent 967c793eaa
commit 17ca9a262b
2 changed files with 18 additions and 0 deletions
@@ -40,6 +40,12 @@ What was built is narrower than what was decided, measured in the controller on
  layer sets it — right for a mail domain, where a default is the very literal 0155 removes, and wrong
  for a tunable like the resolver's upstreams, which the resolver module therefore carries as literals
  in its file.
+- **A setting reaches every mergeable file its module owns.** The layers are one flat map per module,
+  laid over each such file. Adding a setting to the resolver module for its own configuration put the
+  key into the container runtime's file as well — the resolver writes into that file too — and the
+  runtime refuses keys it does not know. The plan showed it before any push; the runtime's file was
+  then made to take no settings at all ([issue 198](../04-ISSUES/198-the-lans-dns-server-ran-outside-the-mesh-and-its-filter-closed-it/00-report.md)). Issue 173 stopped settings leaking into
+  contributions and served facts; between one module's own files the leak remains.
 - **What a change costs is said per file, not per key.** A service names the files it is reloaded or
  restarted on. The runtime re-reads its trusted registries on a reload and its `dns` key only when it
  starts; the resolver module declared a reload, so on two machines the key was written, reloaded,
@@ -80,6 +86,10 @@ A new default ships with the module's next version and reaches every assignment
 it; a mesh-wide setting reaches every assignment of the module; a node's reaches one. The plan of a
 change names each assignment whose effective value moves.

+**A declared setting says where it lands.** Each names the file or files of its module that read it,
+and reaches no other: a module that owns two mergeable files no longer has one flat map laid over both.
+A file that names no setting takes none.
+
 **A declared setting is the only kind accepted.** Setting a key the module does not declare is refused
 when it is set, naming the declared keys, rather than reported when the machine is planned. The mesh's
 own words — where a port, a directory or an operator's data is placed, how far an endpoint reaches —
@@ -121,6 +131,7 @@ its trusted registries are what the mesh tells it.
 |---|---|
 | Every setting a module takes is declared | A parser test refusing a setting declaration without a type or meaning; a catalogue test listing modules with mergeable files or `${setting:}` and no declarations, which must be empty before the implicit form is removed |
 | A tunable resolves to its default; an operator value without one is refused | Resolution tests: an unset tunable in a JSON file and in a text file both take the default; an unset setting with no default is refused naming it (0155's existing test) |
+| A setting reaches only the files it names | A resolution test: a module with two mergeable files and a setting declared for one; the other file's content is unchanged by it (the case of issue 198) |
 | An undeclared key is refused when set | A controller test: `settings set` with an undeclared key fails naming the declared keys, and nothing is stored |
 | Every effective value names its source | A test listing a module's configuration on a node with one key from each of default, mesh and node |
 | A change's reach is shown before it moves | A plan test: changing a mesh-wide setting names every assignment whose effective value moves and no other |