route-proxy: serve a route that names only its internal host

Since ADR 0138 an endpoint that reaches only the private network gets an
internal-name and no name, and the proxy skipped it as naming nothing, so
every internal-only module was unreachable by name (novox/hq issue 191).

examples/route-proxy/main.go

@@ -716,6 +716,12 @@ func boolByte(b bool) byte {
 // routesFrom reads what the mesh wrote and turns it into host → the rules for that host, and
 // which of those hosts is a public name — the second is `name`, ACME-eligible; a host reached
 // only through `internal-name` never appears there.
+//
+// **A route may carry either name, or both** (novox/hq ADR 0138). How far an endpoint reaches
+// decides which names the mesh composes, so an endpoint that reaches only the private network
+// arrives with an `internal-name` and no `name`. That is a whole route, not a malformed one: it is
+// served under its internal name and certified by the internal authority. Only a route with
+// neither name has nothing to be served under (novox/hq issue 191).
 func routesFrom(path string) (map[string][]rule, map[string]bool, error) {
 	raw, err := os.ReadFile(path)
 	if err != nil {
@@ -730,12 +736,18 @@ func routesFrom(path string) (map[string][]rule, map[string]bool, error) {
 	public := map[string]bool{}
 	for _, c := range said.Given {
 		name, _ := c.Values["name"].(string)
-		if name == "" {
+		name = strings.TrimSpace(name)
+		internal, _ := c.Values["internal-name"].(string)
+		internal = strings.TrimSpace(internal)
+		if name == "" && internal == "" {
 			log.Printf("%s on %s asked for a route and named nothing; skipped", c.From, c.Node)
 			continue
 		}
-		host := strings.ToLower(name)
+		// What the route is called in a log line: its public name when it has one.
-		public[host] = true
+		called := name
+		if called == "" {
+			called = internal
+		}
 
 		made := rule{path: asPath(c.Values["path"])}
 		if p, ok := asWhole(c.Values["priority"]); ok {
@@ -752,7 +764,7 @@ func routesFrom(path string) (map[string][]rule, map[string]bool, error) {
 			if looksLikeACredential(named) {
 				log.Printf("%s on %s declared route %q with a credential in the declaration rather "+
 					"than the name of a secret; the whole route is refused (novox/hq ADR 0108)",
-					c.From, c.Node, name)
+					c.From, c.Node, called)
 				continue
 			}
 			users, err := usersFrom(named)
@@ -770,7 +782,7 @@ func routesFrom(path string) (map[string][]rule, map[string]bool, error) {
 			port, ok := asPort(c.Values["port"])
 			if !ok {
 				log.Printf("%s on %s asked for route %q and gave no usable port; skipped",
-					c.From, c.Node, name)
+					c.From, c.Node, called)
 				continue
 			}
 			// Where the mesh says that machine is. Empty means it is this one — a workload beside
@@ -791,7 +803,7 @@ func routesFrom(path string) (map[string][]rule, map[string]bool, error) {
 			}
 			if scheme != "http" && scheme != "https" {
 				log.Printf("%s on %s asked for route %q with scheme %q, which is neither http "+
-					"nor https; skipped", c.From, c.Node, name, scheme)
+					"nor https; skipped", c.From, c.Node, called, scheme)
 				continue
 			}
 			made.insecure, _ = c.Values["insecure"].(bool)
@@ -802,7 +814,7 @@ func routesFrom(path string) (map[string][]rule, map[string]bool, error) {
 				bytes, whole := asWhole(asked)
 				if !whole || bytes <= 0 {
 					log.Printf("%s on %s asked for route %q with a max-request-body of %v, which is "+
-						"not a whole positive number of bytes; skipped", c.From, c.Node, name, asked)
+						"not a whole positive number of bytes; skipped", c.From, c.Node, called, asked)
 					continue
 				}
 				made.maxRequestBody = int64(bytes)
@@ -810,15 +822,20 @@ func routesFrom(path string) (map[string][]rule, map[string]bool, error) {
 			made.target = fmt.Sprintf("%s://%s:%d", scheme, at, port)
 		}
 
+		if name != "" {
+			host := strings.ToLower(name)
 			out[host] = append(out[host], made)
+			public[host] = true
+		}
 
-		// The internal-network alias, the same rule under a second host — a predecessor proxy
+		// The internal-network name, the same rule under a second host — a predecessor proxy
 		// answered both for one route, as a convenience (reaching a service over the VPN without a
 		// public TLS round trip), not as an access boundary; composing it here restores exactly
 		// that, nothing more. Absent whenever the node composed no internal name (novox/hq ADR
 		// 0056's internalDomain half) — the same "nothing to join a label to" case the public name
-		// already has.
+		// already has. And the only name, when the endpoint reaches no further than the private
-		if internal, _ := c.Values["internal-name"].(string); strings.TrimSpace(internal) != "" {
+		// network.
+		if internal != "" {
 			out[strings.ToLower(internal)] = append(out[strings.ToLower(internal)], made)
 		}
 	}

examples/route-proxy/routes_test.go

@@ -90,6 +90,50 @@ func TestARouteWithAnInternalNameIsReachableUnderBoth(t *testing.T) {
 	}
 }
 
+// A route whose endpoint reaches only the private network carries an internal name and no public
+// one (novox/hq ADR 0138), and is served under that name rather than skipped as naming nothing —
+// skipping it left every internal-only module unreachable by name (novox/hq issue 191).
+func TestARouteWithOnlyAnInternalNameIsServed(t *testing.T) {
+	routes, public, err := routesFrom(write(t, `{"given":[
+	  {"from":"app","node":"anchor","at":"anchor.internal",
+	   "values":{"internal-name":"App.Anchor.Internal","port":8443,"scheme":"https","insecure":true}}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if targetOf(routes, "app.anchor.internal") != "https://anchor.internal:8443" {
+		t.Fatalf("the internal-only route is not served: %v", routes)
+	}
+	if len(routes) != 1 {
+		t.Errorf("an internal-only route made hosts it never named: %v", routes)
+	}
+	if len(public) != 0 {
+		t.Errorf("an internal-only route made a name eligible for a public certificate: %v", public)
+	}
+
+	held := newTable()
+	held.set(routes, public)
+	if err := onlyInternalNamesTheMeshSaid(held)(context.Background(), "app.anchor.internal"); err != nil {
+		t.Errorf("the internal authority refused the internal-only route's name: %v", err)
+	}
+	if err := onlyWhatTheMeshSaid(held)(context.Background(), "app.anchor.internal"); err == nil {
+		t.Error("a public certificate was ordered for an internal-only name")
+	}
+}
+
+// A route with neither name has nothing to be served under, and is still skipped.
+func TestARouteWithNeitherNameIsSkipped(t *testing.T) {
+	routes, public, err := routesFrom(write(t, `{"given":[
+	  {"from":"app","node":"anchor","at":"anchor.internal","values":{"internal-name":"  ","port":8080}}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(routes) != 0 || len(public) != 0 {
+		t.Errorf("a route that named nothing was served: %v %v", routes, public)
+	}
+}
+
 // A route with no internal-name composed gets no second host — the ordinary case, unchanged.
 func TestARouteWithNoInternalNameGetsNoAlias(t *testing.T) {
 	routes, _, err := routesFrom(write(t, `{"given":[