Merge pull request 'One predicate for a module the mesh provides itself (mesh-wireguard), used by the placement check (issue 1126)' (#120) from fix/1126-provided into main

go/compose/frombus/frombus.go

@@ -246,15 +246,17 @@ func input(ctx context.Context, r Reader, mesh Mesh, s Scope, refuse func(module
 
 	// The module the mesh provides itself (the private network) has no repository the indexer reads: its manifest comes
 	// with mesh-sdk and always wins, as the controller's providedModules and the grants part have it.
-	provided, err := json.Marshal(overlay.Manifest())
+	for _, name := range delivery.ProvidedModules() {
-	if err != nil {
+		raw, err := json.Marshal(overlay.Manifest())
-		return compose.Input{}, err
+		if err != nil {
+			return compose.Input{}, err
+		}
+		var private catalogue.Manifest
+		if err := json.Unmarshal(raw, &private); err != nil {
+			return compose.Input{}, fmt.Errorf("frombus: the manifest mesh-sdk provides for %s: %w", name, err)
+		}
+		in.Catalogue[name] = private
 	}
-	var private catalogue.Manifest
-	if err := json.Unmarshal(provided, &private); err != nil {
-		return compose.Input{}, fmt.Errorf("frombus: the private network's manifest mesh-sdk provides: %w", err)
-	}
-	in.Catalogue[overlay.Name] = private
 
 	var missing []string
 	for _, node := range nodesOf(placements, records) {

go/delivery/placement.go

@@ -413,7 +413,7 @@ func CheckPlacements(placements map[string]Placement, held func(module string) b
 		}
 		hostPorts := map[int]string{}
 		for _, m := range p.Modules {
-			if !held(m.Module) {
+			if !held(m.Module) && !ProvidedByMesh(m.Module) { // the mesh provides the private network itself
 				refusals = append(refusals, fmt.Sprintf("%s: the indexer holds no module %s", node, m.Module))
 			}
 			for _, port := range sortedKeys(m.Ports) {

go/delivery/placement_test.go

@@ -155,6 +155,16 @@ func TestPlacement(t *testing.T) {
 		if r := CheckPlacements(map[string]Placement{"g14": g14, "novox": novox}, held, enrolled); len(r) != 0 {
 			t.Fatalf("a sound placement is refused: %v", r)
 		}
+		// Issue 1126: the private network is the mesh's own module, held by no repository the indexer reads, and placed on
+		// every node by the seed; the check takes it whatever the indexer holds.
+		wired := Placement{Node: "novox", Modules: []PlacedModule{{Module: "mesh-wireguard"}}}
+		if r := CheckPlacements(map[string]Placement{"novox": wired}, func(string) bool { return false }, enrolled); len(r) != 0 ||
+			!ProvidedByMesh("mesh-wireguard") || ProvidedByMesh("postgres") {
+			t.Errorf("the private network placed with no repository holding it is refused: %v", r)
+		}
+		if m, _, err := ProvidedManifest("mesh-wireguard"); err != nil || m.Module != "mesh-wireguard" {
+			t.Errorf("the provided manifest = %+v, %v", m, err)
+		}
 		// A replicated mesh seat (ADR 0223) is held on two nodes; a seat that is not replicated is refused there.
 		for seat, refused := range map[string]bool{"mesh-dns-resolver": false, "mesh-broker": true} {
 			a := Placement{Node: "ace", Modules: []PlacedModule{{Module: "dns"}}, Holds: []Holding{{Claim: seat, Scope: "mesh", Module: "dns"}}}

go/delivery/provided.go

@@ -0,0 +1,37 @@
+package delivery
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/overlay"
+)
+
+// The modules the mesh provides itself (issue 1126): no repository holds them, so the indexer reads none; their
+// manifests come with mesh-sdk, built in code, and always win over any other. Today the private network alone
+// (overlay.Name), built by nobody and run inside each node's own composition. One predicate for every part that judges
+// or composes a placement: CheckPlacements, the seat's holder, the composer's input (frombus) and the grants part.
+
+// ProvidedModules is every module the mesh provides itself, sorted.
+func ProvidedModules() []string { return []string{overlay.Name} }
+
+// ProvidedByMesh says whether the mesh provides module itself, so a placement may name it with no repository holding it.
+func ProvidedByMesh(module string) bool { return module == overlay.Name }
+
+// ProvidedManifest is a provided module's manifest, as its readers parse it, and its raw JSON; an error for a module the
+// mesh does not provide or a manifest its own reader refuses.
+func ProvidedManifest(module string) (catalogue.Manifest, []byte, error) {
+	if !ProvidedByMesh(module) {
+		return catalogue.Manifest{}, nil, fmt.Errorf("delivery: the mesh provides no module %s", module)
+	}
+	raw, err := json.Marshal(overlay.Manifest())
+	if err != nil {
+		return catalogue.Manifest{}, nil, err
+	}
+	m, err := catalogue.ParseManifestForInputs(raw)
+	if err != nil {
+		return catalogue.Manifest{}, raw, fmt.Errorf("delivery: the manifest mesh-sdk provides for %s is refused by its own reader: %w", module, err)
+	}
+	return m, raw, nil
+}