Keep the list from a catalogue build, and carry it and mesh and node config through the facts and the gate (hq issue 630)

The merge gate must compose with the same config the mesh holds, and judge a catalogue change against the list it brings.

cmd/mesh-controller/check.go

@@ -47,6 +47,13 @@ func moduleCheckFor(paths []string, longestMachine int, out io.Writer) error {
 	shelf := catalogue.Shelf{}
 	faulted := map[string]bool{}
 	failed := 0
+	// The list of predefined keys a preference may fall back to (novox/hq issue 630): the predefined.json
+	// at the root of the repository the manifests are in, found above the first of them.
+	list, listAt, listErr := predefinedAbove(paths[0])
+	if listErr != nil {
+		fmt.Fprintf(out, "%s: %v\n", listAt, listErr)
+		failed++
+	}
 	for _, path := range paths {
 		raw, err := os.ReadFile(path)
 		if err != nil {
@@ -92,6 +99,20 @@ func moduleCheckFor(paths []string, longestMachine int, out io.Writer) error {
 			failed += len(named)
 			faulted[m.Module] = true
 		}
+		// A preference falls back only to a key on the list, with its type (novox/hq issue 630).
+		if named := catalogue.PredefinedNamed(m); len(named) > 0 {
+			if listAt == "" {
+				fmt.Fprintf(out, "note: %s: its preferences fall back to %s, and no %s was found above it; "+
+					"registration judges them against the list the mesh holds\n", path, strings.Join(named, ", "),
+					catalogue.PredefinedFile)
+			} else if wrong := catalogue.PredefinedProblems(m, list); len(wrong) > 0 {
+				for _, p := range wrong {
+					fmt.Fprintf(out, "%s: %s\n", path, p)
+				}
+				failed += len(wrong)
+				faulted[m.Module] = true
+			}
+		}
 		shelf[m.Module] = m
 	}
 
@@ -285,3 +306,27 @@ func manifestsUnder(dir string) ([]string, error) {
 	sort.Strings(found)
 	return found, err
 }
+
+// predefinedAbove reads the predefined.json found in the directory of a manifest or one above it, up to
+// the repository's root (the directory holding .git). The path it was found at is "" when there is none.
+func predefinedAbove(manifest string) (catalogue.Predefined, string, error) {
+	dir, err := filepath.Abs(filepath.Dir(manifest))
+	if err != nil {
+		return nil, "", nil
+	}
+	for {
+		at := filepath.Join(dir, catalogue.PredefinedFile)
+		if raw, err := os.ReadFile(at); err == nil {
+			list, err := catalogue.ParsePredefined(raw)
+			return list, at, err
+		}
+		if _, err := os.Stat(filepath.Join(dir, ".git")); err == nil {
+			return nil, "", nil
+		}
+		up := filepath.Dir(dir)
+		if up == dir {
+			return nil, "", nil
+		}
+		dir = up
+	}
+}