Merge pull request 'The proxy is told its routes and the mesh on the bus, and serves internal names to the mesh only (hq issue 191, ADR 0167)' (#207) from jschoubben/an-internal-only-route into main

internal/catalogue/declaration.go

@@ -241,15 +241,21 @@ func (r Resolution) Declaration(with Rendering) ([]map[string]any, error) {
 // Owner is kept beside the resources because a resource id cannot be split back into its module:
 // a module's name may itself contain a dot. What the mesh adds of its own — an opening, the guard —
 // has no owner.
+//
+// Received is what each module on the machine is given for each requirement it receives — the same
+// contributions its received file is written from, kept beside it so the mesh can also issue them
+// on the bus in the module's membership (novox/hq ADR 0167). By module, then requirement.
 type Composed struct {
 	Resources []map[string]any
 	Owner     map[string]string
+	Received  map[string]map[string][]Contribution
 }
 
 // Compose is Declaration with the owner of every resource said.
 func (r Resolution) Compose(with Rendering) (Composed, error) {
 	owner := map[string]string{}
-	resources, err := r.compose(with, owner)
+	received := map[string]map[string][]Contribution{}
+	resources, err := r.compose(with, owner, received)
 	if err != nil {
 		return Composed{}, err
 	}
@@ -261,7 +267,7 @@ func (r Resolution) Compose(with Rendering) (Composed, error) {
 			"sealed": with.BusMembership, "mode": "0600",
 		})
 	}
-	return Composed{Resources: resources, Owner: owner}, nil
+	return Composed{Resources: resources, Owner: owner, Received: received}, nil
 }
 
 // BusMembershipID names the resource carrying a machine's membership for the new bus, and
@@ -270,7 +276,8 @@ func BusMembershipID() string { return "bus-membership" }
 
 const BusMembershipPath = "/var/lib/mesh/membership-next.json"
 
-func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[string]any, error) {
+func (r Resolution) compose(with Rendering, owner map[string]string,
+	received map[string]map[string][]Contribution) ([]map[string]any, error) {
 	// Every manifest is placed first (novox/hq ADR 0112): the maps naming where its bindings,
 	// credentials and contributions land are resolved against this node's directories, so every
 	// reader below — the binding files, the sealed secrets, the grant paths a contribution
@@ -596,6 +603,12 @@ func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[stri
 				return nil, err
 			}
 			first = append(first, file)
+			if received[m.Module] == nil {
+				received[m.Module] = map[string][]Contribution{}
+			}
+			// Empty rather than absent when nobody contributed, for the reason the file is
+			// written empty: "nothing asked" and "never told" want different responses.
+			received[m.Module][to] = append([]Contribution{}, given[to]...)
 		}
 		if m.Keeps != "" && with.Kept != nil {
 			file, err := keptFile(m.Keeps, with.Kept)

internal/catalogue/received_on_the_bus_test.go

@@ -0,0 +1,66 @@
+package catalogue
+
+import (
+	"encoding/json"
+	"reflect"
+	"testing"
+)
+
+// What a provider receives is composed once, and issued twice: as its received file, and in its
+// membership on the bus (novox/hq ADR 0167). The two are the same list, so a proxy reading the bus
+// and one reading the file serve the same routes — including the port the machine published, which
+// is the same-node fix the file already carries.
+func TestWhatAProviderReceivesIsTheSameOnTheBusAsInItsFile(t *testing.T) {
+	gitea := Manifest{
+		Module: "gitea", Version: "1",
+		Listens:     []Listening{{Port: 3000, Protocol: "tcp", From: FromMesh}},
+		Contributes: map[string]map[string]any{"route": {"label": "git", "port": 3000}},
+		Resources: []map[string]any{{
+			"id": "server", "type": "container", "name": "gitea", "ports": []any{"3000"},
+		}},
+	}
+	r, err := Resolve(shelf(gitea, routeProxy(), stepCA()),
+		[]string{"gitea", "route-proxy", "step-ca"}, reachable(), World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	composed, err := r.Compose(Rendering{Ports: map[string]map[int]int{"gitea": {3000: 20000}}})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	file := fileNamed(composed.Resources, "route-proxy.received-route")
+	if file == nil {
+		t.Fatal("the proxy was given no routes file")
+	}
+	var written struct {
+		Given []Contribution `json:"given"`
+	}
+	if err := json.Unmarshal([]byte(file["content"].(string)), &written); err != nil {
+		t.Fatal(err)
+	}
+	issued, said := composed.Received["route-proxy"]["route"]
+	if !said {
+		t.Fatalf("nothing is issued for the proxy to receive on the bus: %v", composed.Received)
+	}
+	// Compared as JSON, which is what both are once they leave the controller.
+	a, _ := json.Marshal(written.Given)
+	b, _ := json.Marshal(issued)
+	var fromFile, fromBus any
+	_ = json.Unmarshal(a, &fromFile)
+	_ = json.Unmarshal(b, &fromBus)
+	if !reflect.DeepEqual(fromFile, fromBus) {
+		t.Errorf("the bus and the file disagree about the routes:\nfile %s\nbus  %s", a, b)
+	}
+	if len(issued) != 1 {
+		t.Fatalf("expected one route on the bus, got %v", issued)
+	}
+	if port, ok := asPort(issued[0].Values["port"]); !ok || port != 20000 {
+		t.Errorf("the bus carries a port nothing listens on: %v", issued[0].Values["port"])
+	}
+
+	// A module that receives nothing is issued nothing to receive.
+	if _, any := composed.Received["gitea"]; any {
+		t.Errorf("a module that receives nothing was issued something: %v", composed.Received["gitea"])
+	}
+}