A setting reaches only what declares it, the mesh places its own files, registration refuses a name

Three of novox/hq's group-4 leftovers, one branch.

Issue 173: a module's settings reached every route it contributed, every database it asked for and
every served fact its consumers read — a mail server's site name arrived at the proxy as a route
fact. A setting now overrides a key a contribution or served fact declares and adds none; a file
still merges any key, and a key nothing takes is named as stray instead of dropped silently.

Issue 174: the mesh's own files for a module — its bus credential, its merged config, its bindings —
were placed by the definition under /var/lib/mesh/<module>, 232 host paths in 50 definitions. A
directory may now say `place: "mesh"` and resolves to <root>/mesh/<module>; a directory beneath a
placed one may state its path as `${dir:<id>}/<rest>` and moves with it. The proof test resolves
both catalogues and compares: 48 definitions, no path moved. The controller's own manifest is
converted here; the catalogue in mesh-catalog.

ADR 0155: the installation check moves to registration. `module add` and a build's result both
refuse a definition that names an installation, in the check's words, with the way out; the build
stays recorded.

cmd/mesh-controller/build.go

@@ -479,6 +479,12 @@ func buildOne(ctx context.Context, source buildSource, path, ref string, wait ti
 	if source.Seat != "" {
 		recorded.Repository, recorded.Seat = source.Repository, source.Seat
 	}
+	// The build is kept; the module is not. A definition naming an installation is refused where
+	// it would enter the catalogue, and the build log says which build it was.
+	if err := namesNoInstallation(manifest); err != nil {
+		return fmt.Errorf("%s built %s (%s), and the mesh does not register it: %w",
+			result.On, result.Repository, short(result.Commit), err)
+	}
 	if err := inv.RegisterModule(ctx, manifest, recorded); err != nil {
 		return err
 	}

cmd/mesh-controller/check.go

@@ -51,8 +51,8 @@ func moduleCheck(paths []string, out io.Writer) error {
 			failed++
 			continue
 		}
-		// A definition names no installation (novox/hq ADR 0112, ADR 0155): judged here and in the
-		// catalogue-wide test, not yet at registration, while the declared exceptions shrink.
+		// A definition names no installation (novox/hq ADR 0112, ADR 0155): judged here, in the
+		// catalogue-wide test, and at registration, which refuses in the same words.
 		if named := catalogue.InstallationProblems(m); len(named) > 0 {
 			for _, p := range named {
 				fmt.Fprintf(out, "%s: %s\n", path, p)

cmd/mesh-controller/check_test.go

@@ -5,6 +5,8 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
 	"testing"
 )
 
@@ -67,3 +69,26 @@ func TestModuleCheckPassesTheCatalogue(t *testing.T) {
 		t.Fatalf("the catalogue does not pass its own check: %v\n%s", err, out.String())
 	}
 }
+
+func TestRegistrationRefusesADefinitionNamingAnInstallation(t *testing.T) {
+	// novox/hq ADR 0155: the check moves to registration once the catalogue passes it. Both
+	// ways in — `module add` and a build's result — go through this, and a name declared on
+	// purpose passes with its reason.
+	named := catalogue.Manifest{Module: "idp", Resources: []map[string]any{
+		{"id": "server", "type": "container", "image": "x@sha256:aa",
+			"env": map[string]any{"KC_HOSTNAME": "https://login.mesh-one.be"}},
+	}}
+	err := namesNoInstallation(named)
+	if err == nil || !strings.Contains(err.Error(), "login.mesh-one.be") ||
+		!strings.Contains(err.Error(), catalogue.NamesOnPurpose) {
+		t.Fatalf("a definition naming an installation is refused with the name and the way out; got %v", err)
+	}
+	meant := catalogue.Manifest{Module: "site", Resources: []map[string]any{
+		{"id": "server", "type": "container", "image": "registry.mesh-one.be/org/site@sha256:cc",
+			catalogue.NamesOnPurpose: map[string]any{
+				"registry.mesh-one.be": "built outside the mesh until its repository is a build source here"}},
+	}}
+	if err := namesNoInstallation(meant); err != nil {
+		t.Fatalf("a name declared on purpose passes; got %v", err)
+	}
+}

cmd/mesh-controller/modules.go

@@ -113,6 +113,9 @@ func moduleCommand(ctx context.Context, args []string) error {
 		if err != nil {
 			return err
 		}
+		if err := namesNoInstallation(m); err != nil {
+			return err
+		}
 		if err := inv.RegisterModule(ctx, m, from); err != nil {
 			return err
 		}
@@ -662,3 +665,18 @@ func whereItComesFrom(repository, ref, commit, path string, self bool) (inventor
 	}
 	return from, nil
 }
+
+// namesNoInstallation is the mesh refusing a definition that names an installation, at the moment
+// it would enter the catalogue (novox/hq ADR 0112, ADR 0155). `module check` says the same thing
+// earlier, where the author is; this is the last moment the mesh can still say no, and a
+// definition that got past the check — written elsewhere, or checked by nobody — is refused here
+// in the same words. A name meant on purpose is declared with its reason and passes.
+func namesNoInstallation(m catalogue.Manifest) error {
+	named := catalogue.InstallationProblems(m)
+	if len(named) == 0 {
+		return nil
+	}
+	return fmt.Errorf("%s names an installation, and a definition names none — declare a name meant "+
+		"on purpose under %s with its reason, or take it out:\n  - %s",
+		m.Module, catalogue.NamesOnPurpose, strings.Join(named, "\n  - "))
+}