Merge pull request 'A module may invoke tools, and a manifest is checked where it is written' (#164) from feat/the-console into main

Reviewed-on: #164

cmd/mesh-controller/check.go

@@ -0,0 +1,122 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sort"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// moduleCheck judges manifests where they are written, with no mesh (novox/hq ADR 0037, issue 148).
+//
+// **The same functions registration runs, and nothing the command line adds** (ADR 0035): the strict
+// parse with every per-manifest problem, then the rules no single manifest can be judged against,
+// over exactly the manifests given. Somebody describing their own application in their own
+// repository runs this before pushing and finds out there, rather than when a running mesh refuses
+// the registration or, later, when a machine applies something that resolved and should not have.
+//
+// **What it cannot know without a store, it says.** The mesh's own seat set is the store's (ADR
+// 0122); this binary carries a compiled copy that the store overrides when loaded, so a claim on a
+// mesh seat is judged fully only at registration. A seat another module declares is unknown unless
+// that module's manifest is passed too. Both are printed as a note, not as a problem — a check that
+// refused what it could not see would teach people to ignore it.
+func moduleCheck(paths []string, out io.Writer) error {
+	if len(paths) == 0 {
+		return errors.New("module check <manifest.json>... — one file per module; pass every " +
+			"manifest of a repository together so the rules between them are checked too")
+	}
+	shelf := catalogue.Shelf{}
+	failed := 0
+	for _, path := range paths {
+		raw, err := os.ReadFile(path)
+		if err != nil {
+			fmt.Fprintf(out, "%s: %v\n", path, err)
+			failed++
+			continue
+		}
+		m, err := catalogue.ParseManifest(raw)
+		if err != nil {
+			fmt.Fprintf(out, "%s: %v\n", path, err)
+			failed++
+			continue
+		}
+		if first, twice := shelf[m.Module]; twice {
+			_ = first
+			fmt.Fprintf(out, "%s: %s was already given; two manifests name one module\n", path, m.Module)
+			failed++
+			continue
+		}
+		shelf[m.Module] = m
+	}
+
+	// Between the manifests: a seat declared twice, a use of a seat nothing declares, a claim on
+	// a seat that does not exist. Run only over what parsed, because a problem inside one manifest
+	// has already been said and would be said again here in a worse form.
+	problems := catalogue.CatalogueProblems(shelf)
+	sort.Strings(problems)
+	for _, p := range problems {
+		fmt.Fprintln(out, p)
+	}
+	failed += len(problems)
+
+	var names []string
+	for name := range shelf {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	for _, name := range names {
+		m := shelf[name]
+		fmt.Fprintf(out, "%s: ok", name)
+		if n := len(m.Tools); n > 0 {
+			fmt.Fprintf(out, ", %d tool(s)", n)
+		}
+		if len(m.Invokes) > 0 {
+			fmt.Fprintf(out, ", invokes %s", joinInvokes(m.Invokes))
+		}
+		fmt.Fprintln(out)
+	}
+	if failed > 0 {
+		return fmt.Errorf("%d problem(s) in %d manifest(s)", failed, len(paths))
+	}
+	fmt.Fprintf(out, "%d manifest(s) checked. Judged against the seats this binary carries; a claim on "+
+		"one of the mesh's own seats is judged fully at registration, and a seat declared by a "+
+		"module not given here reads as unknown\n", len(paths))
+	return nil
+}
+
+func joinInvokes(invokes []string) string {
+	if len(invokes) == 1 && invokes[0] == "*" {
+		return "every tool"
+	}
+	s := ""
+	for i, t := range invokes {
+		if i > 0 {
+			s += ", "
+		}
+		s += t
+	}
+	return s
+}
+
+// manifestsUnder lists every module.json below a directory, for `module check <dir>`.
+func manifestsUnder(dir string) ([]string, error) {
+	var found []string
+	err := filepath.WalkDir(dir, func(path string, d os.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if d.IsDir() && (d.Name() == "node_modules" || d.Name() == ".git" || d.Name() == "dist") {
+			return filepath.SkipDir
+		}
+		if !d.IsDir() && d.Name() == "module.json" {
+			found = append(found, path)
+		}
+		return nil
+	})
+	sort.Strings(found)
+	return found, err
+}

cmd/mesh-controller/check_test.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// The check anybody can run is the check registration runs (novox/hq issue 148, ADR 0037): a manifest
+// with a known fault is named, and one without passes, with no store opened.
+func TestModuleCheckNamesAFaultAndNeedsNoMesh(t *testing.T) {
+	dir := t.TempDir()
+	good := filepath.Join(dir, "good.json")
+	bad := filepath.Join(dir, "bad.json")
+	os.WriteFile(good, []byte(`{"module":"shop","version":"1","tools":["price"],"invokes":["mesh-catalog.catalog_modules"]}`), 0o600)
+	os.WriteFile(bad, []byte(`{"module":"till","version":"1","invokes":["shop"]}`), 0o600)
+
+	var out bytes.Buffer
+	if err := moduleCheck([]string{good}, &out); err != nil {
+		t.Fatalf("a sound manifest was refused: %v\n%s", err, out.String())
+	}
+	if !strings.Contains(out.String(), "shop: ok, 1 tool(s), invokes mesh-catalog.catalog_modules") {
+		t.Fatalf("the report does not say what it checked:\n%s", out.String())
+	}
+
+	out.Reset()
+	err := moduleCheck([]string{good, bad}, &out)
+	if err == nil {
+		t.Fatal("a manifest invoking a module and no tool passed")
+	}
+	if !strings.Contains(out.String(), `till invokes "shop", which does not name a tool`) {
+		t.Fatalf("the fault is not named in the manifest's words:\n%s", out.String())
+	}
+}
+
+// The rules between manifests run over what was given together: a seat two modules declare is
+// refused, which no single-manifest check can see.
+func TestModuleCheckJudgesBetweenTheManifestsGiven(t *testing.T) {
+	dir := t.TempDir()
+	a := filepath.Join(dir, "a.json")
+	b := filepath.Join(dir, "b.json")
+	os.WriteFile(a, []byte(`{"module":"a","version":"1","seats":[{"name":"printer","scope":"mesh"}]}`), 0o600)
+	os.WriteFile(b, []byte(`{"module":"b","version":"1","seats":[{"name":"printer","scope":"mesh"}]}`), 0o600)
+	var out bytes.Buffer
+	if err := moduleCheck([]string{a, b}, &out); err == nil {
+		t.Fatalf("two declarations of one seat passed:\n%s", out.String())
+	}
+	if !strings.Contains(out.String(), "a seat name means one protocol") {
+		t.Fatalf("the cross-manifest rule was not the one named:\n%s", out.String())
+	}
+}
+
+// The real catalogue passes the command, the way it passes the test that used to be the only check.
+func TestModuleCheckPassesTheCatalogue(t *testing.T) {
+	root := filepath.Join("..", "..", "..", "mesh-catalog", "modules")
+	if _, err := os.Stat(root); err != nil {
+		t.Skipf("catalogue sibling not present: %v", err)
+	}
+	paths, err := manifestsUnder(root)
+	if err != nil || len(paths) == 0 {
+		t.Fatalf("no manifests under %s: %v", root, err)
+	}
+	var out bytes.Buffer
+	if err := moduleCheck(paths, &out); err != nil {
+		t.Fatalf("the catalogue does not pass its own check: %v\n%s", err, out.String())
+	}
+}

cmd/mesh-controller/main.go

@@ -161,6 +161,7 @@ func usage() {
   overlay place <node> [flags]   say where a node is and how it is reached
   overlay show                   the private network, as the mesh computes it
   module add <file>              register a module from its manifest
+  module check <file|dir>...     judge manifests where they are written, with no mesh (exit 1 on any problem)
   module list                    what modules this mesh knows about
   module moved <name> <commit>   the source has a newer commit than the mesh built
   module forget <name>           remove one, unless a node runs it or the mesh holds things for it

cmd/mesh-controller/modules.go

@@ -54,7 +54,24 @@ var provided = providedModules()
 
 func moduleCommand(ctx context.Context, args []string) error {
 	if len(args) == 0 {
-		return errors.New("module add <file>, module list, or module forget <name>")
+		return errors.New("module add <file>, module check <file>..., module list, or module forget <name>")
+	}
+	// `check` needs no mesh, and must not: it is what somebody runs in their own repository before
+	// there is a mesh in reach (novox/hq issue 148). A directory expands to every manifest under it.
+	if args[0] == "check" {
+		var paths []string
+		for _, a := range args[1:] {
+			if info, err := os.Stat(a); err == nil && info.IsDir() {
+				under, err := manifestsUnder(a)
+				if err != nil {
+					return err
+				}
+				paths = append(paths, under...)
+				continue
+			}
+			paths = append(paths, a)
+		}
+		return moduleCheck(paths, os.Stdout)
 	}
 	open, err := openStores(ctx)
 	if err != nil {
@@ -275,7 +292,7 @@ func moduleCommand(ctx context.Context, args []string) error {
 		return issueOnTheNewBus(ctx, inv, m, *forNode, busAddress)
 
 	default:
-		return fmt.Errorf("module has no %q; it has add, list, moved, forget and issue", args[0])
+		return fmt.Errorf("module has no %q; it has add, check, list, moved, forget and issue", args[0])
 	}
 }
 

internal/broker/invokes_test.go

@@ -0,0 +1,92 @@
+package broker
+
+import (
+	"strings"
+	"testing"
+)
+
+// A module that says it calls a tool may publish exactly that subject (novox/hq ADR 0152): the same
+// grant a person gets, derived the same way, so one list answers "what may this ask" for everybody.
+func TestAModuleMayAskOnlyTheToolsItInvokes(t *testing.T) {
+	perms, err := PermissionsFor(Principal{Kind: KindModule, Node: "desk", Module: "mesh-console",
+		Invokes: []string{"shop.price"}, PasswordHash: "x"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	has(t, perms.Publish, "mesh.mod.shop.tool.price")
+	hasNot(t, perms.Publish, "mesh.mod.shop.tool.refund")
+	hasNot(t, perms.Publish, "mesh.mod.*.tool.>")
+}
+
+// The console's grant: every tool, as one subject, and it reads as one.
+func TestAModuleInvokingEverythingMayAskAnyTool(t *testing.T) {
+	perms, err := PermissionsFor(Principal{Kind: KindModule, Node: "desk", Module: "mesh-console",
+		Invokes: []string{"*"}, PasswordHash: "x"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	has(t, perms.Publish, "mesh.mod.*.tool.>")
+}
+
+// **A grant to call widens nothing else.** A module that invokes may not publish an event it did not
+// declare, may not answer as another module, and subscribes nothing it did not consume — the
+// difference between the console and a person is that the console is on a machine, not that it may
+// do more.
+func TestInvokingGrantsNothingButTheCall(t *testing.T) {
+	perms, err := PermissionsFor(Principal{Kind: KindModule, Node: "desk", Module: "mesh-console",
+		Invokes: []string{"*"}, PasswordHash: "x"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, p := range perms.Publish {
+		if strings.Contains(p, ".event.") {
+			t.Errorf("a module that only invokes may publish %q, an event it never declared", p)
+		}
+		if strings.HasPrefix(p, "mesh.seat.") {
+			t.Errorf("a module that only invokes may publish %q, a seat it neither holds nor uses", p)
+		}
+	}
+	for _, s := range perms.Subscribe {
+		if strings.Contains(s, ".tool.") && !strings.HasPrefix(s, "mesh.mod.mesh-console.") {
+			t.Errorf("a module that invokes may subscribe %q, another module's tools", s)
+		}
+	}
+}
+
+// A module that declares no invokes calls nothing, which is every module but the console.
+func TestAModuleThatInvokesNothingCallsNothing(t *testing.T) {
+	perms, err := PermissionsFor(Principal{Kind: KindModule, Node: "one", Module: "shop",
+		Emits: []string{"order.placed"}, PasswordHash: "x"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, p := range perms.Publish {
+		if strings.Contains(p, ".tool.") {
+			t.Errorf("a module with no invokes may publish %q", p)
+		}
+	}
+}
+
+// The malformed entry is refused for a module as it is for a person, and in the same words.
+func TestAModulesToolGrantThatNamesNoToolIsRefused(t *testing.T) {
+	if _, err := PermissionsFor(Principal{Kind: KindModule, Node: "one", Module: "shop",
+		Invokes: []string{"telegram"}, PasswordHash: "x"}); err == nil {
+		t.Fatal("a grant naming a module but no tool was accepted")
+	}
+}
+
+// What a declaration says reaches the composed user, so a manifest's `invokes` is the grant.
+func TestADeclaredInvokeReachesTheComposedUser(t *testing.T) {
+	users, err := Users(Records{
+		Nodes:    []string{"desk"},
+		Assigned: map[string][]Declared{"desk": {{Module: "mesh-console", Invokes: []string{"*"}}}},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	perms, err := PermissionsFor(users[len(users)-1])
+	if err != nil {
+		t.Fatal(err)
+	}
+	has(t, perms.Publish, "mesh.mod.*.tool.>")
+}

internal/broker/nats.go

@@ -70,12 +70,14 @@ type Principal struct {
 	// a namespace no such module owns. Every service started and the graph stayed empty.
 	Watches []Seat
 
-	// Invokes are the tools a person may call, as `<module>.<tool>`; a single `*` is every tool,
-	// for an administrator. Only meaningful for KindPerson.
+	// Invokes are the tools this principal may call, as `<module>.<tool>`; a single `*` is every
+	// tool. A person's whole authority (design 25 §7), and a module's only if its manifest says so
+	// (novox/hq ADR 0152) — the console's does, and nothing else's.
 	//
 	// **A list, not a role.** A person is not a module and holds no seat: nothing is addressed
 	// to them, nothing is delivered to them, and they have no durable consumer to acknowledge.
-	// What they have is permission to ask.
+	// What they have is permission to ask. A module that invokes gains exactly the same
+	// permission and nothing beside it.
 	Invokes []string
 
 	// PasswordHash is the bcrypt hash the mesh minted. The plaintext is sealed to the principal
@@ -224,18 +226,11 @@ func PermissionsFor(p Principal) (Permissions, error) {
 	case KindPerson:
 		// Tools, and nothing else. Every subject a person may publish is a tool call; a person
 		// who could publish an event would be able to claim a module said something.
-		for _, t := range p.Invokes {
-			if t == "*" {
-				pub = append(pub, "mesh.mod.*.tool.>")
-				continue
-			}
-			module, tool, ok := strings.Cut(t, ".")
-			if !ok {
-				return Permissions{}, fmt.Errorf(
-					"%q does not name a tool: a person invokes <module>.<tool>, or * for every one", t)
-			}
-			pub = append(pub, "mesh.mod."+module+".tool."+tool)
+		invoked, err := invokedSubjects(p.Invokes)
+		if err != nil {
+			return Permissions{}, err
 		}
+		pub = append(pub, invoked...)
 
 	case KindEnrolment:
 		// A leaked token is useless for anything but enrolling: it cannot read a declaration, hear
@@ -293,6 +288,16 @@ func PermissionsFor(p Principal) (Permissions, error) {
 		// still granted per tool, by name, on the publish side.
 		sub = append(sub, own+".tool.>")
 
+		// 1b. The tools it calls, if its manifest says it calls any (novox/hq ADR 0152). The same
+		//     grant a person gets and derived the same way, so "what may this module ask" is
+		//     answered by the one list that answers it for everybody. Publish only: an answer
+		//     arrives on its own inbox, which every principal has below.
+		invoked, err := invokedSubjects(p.Invokes)
+		if err != nil {
+			return Permissions{}, err
+		}
+		pub = append(pub, invoked...)
+
 		// 2. What it consumes, by the emitter's own subject — an event is addressed to its
 		//    emitter, because the emitter's identity is the meaning (ADR 0118).
 		for _, c := range p.Consumes {
@@ -601,3 +606,24 @@ func quoted(values []string) string {
 	}
 	return strings.Join(out, ", ")
 }
+
+// invokedSubjects is the publish side of a grant to call tools: one subject per `<module>.<tool>`,
+// or the whole tool namespace for `*`. A person's authority and a module's `invokes` are both this
+// (novox/hq ADR 0152), so a malformed entry is refused in one place, before it could be widened into
+// something that happens to parse.
+func invokedSubjects(invokes []string) ([]string, error) {
+	var out []string
+	for _, t := range invokes {
+		if t == "*" {
+			out = append(out, "mesh.mod.*.tool.>")
+			continue
+		}
+		module, tool, ok := strings.Cut(t, ".")
+		if !ok || module == "" || tool == "" {
+			return nil, fmt.Errorf(
+				"%q does not name a tool: one invokes <module>.<tool>, or * for every one", t)
+		}
+		out = append(out, "mesh.mod."+module+".tool."+tool)
+	}
+	return out, nil
+}

internal/broker/users.go

@@ -31,6 +31,8 @@ type Declared struct {
 	Uses []Seat
 	// Watches are the seats whose events it consumes.
 	Watches []Seat
+	// Invokes are the tools it calls, `<module>.<tool>` or `*` (novox/hq ADR 0152).
+	Invokes []string
 }
 
 // Records is what composing a user list needs to know about the mesh, and nothing more.
@@ -61,7 +63,7 @@ func Users(r Records) ([]Principal, error) {
 			out = append(out, Principal{
 				Kind: KindModule, Node: node, Module: d.Module,
 				Emits: d.Emits, Consumes: d.Consumes, Serves: d.Serves,
-				Holds: d.Holds, Uses: d.Uses, Watches: d.Watches,
+				Holds: d.Holds, Uses: d.Uses, Watches: d.Watches, Invokes: d.Invokes,
 			})
 		}
 	}

internal/catalogue/invokes_test.go

@@ -0,0 +1,31 @@
+package catalogue
+
+import (
+	"strings"
+	"testing"
+)
+
+// A manifest may say which tools its module calls (novox/hq ADR 0152), and the parser accepts the
+// two shapes the grant has: a named tool, and every tool.
+func TestAManifestMaySayWhatItInvokes(t *testing.T) {
+	m, err := ParseManifest([]byte(`{"module":"mesh-console","version":"1",` +
+		`"invokes":["mesh-catalog.catalog_modules","*"]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(m.Invokes) != 2 || m.Invokes[1] != "*" {
+		t.Fatalf("invokes not read: %v", m.Invokes)
+	}
+}
+
+// An entry that names a module and no tool is refused at parse, in the manifest's words, rather than
+// at the composition of the bus's user list where it would stop the file for everybody.
+func TestAnInvokeThatNamesNoToolIsRefusedAtParse(t *testing.T) {
+	_, err := ParseManifest([]byte(`{"module":"mesh-console","version":"1","invokes":["shop"]}`))
+	if err == nil {
+		t.Fatal("an invoke naming no tool was accepted")
+	}
+	if !strings.Contains(err.Error(), `invokes "shop", which does not name a tool`) {
+		t.Fatalf("refused for the wrong reason: %v", err)
+	}
+}

internal/catalogue/manifest.go

@@ -42,6 +42,11 @@ var renamed = map[string]string{
 
 var name = regexp.MustCompile(`^[a-z0-9][a-z0-9-]*(\.[a-z0-9][a-z0-9-]*)*$`)
 
+// toolName is what a module calls one of its tools: the sdk's tools are `catalog_modules` and
+// `gitea_list_repos`, so an underscore is ordinary here and a dot is not — the dot is what separates
+// the module from the tool in `<module>.<tool>`, and a tool name carrying one would be two grants.
+var toolName = regexp.MustCompile(`^[a-z0-9][a-z0-9_-]*$`)
+
 // Claim is a singular resource a module takes over.
 type Claim struct {
 	Name string `json:"name"`
@@ -247,6 +252,16 @@ type Manifest struct {
 	// module claiming a seat answers what that seat's protocol promises (novox/hq ADR 0118).
 	Tools []string `json:"tools,omitempty"`
 
+	// Invokes are the tools this module calls, each `<module>.<tool>`, or the single entry `*` for
+	// every tool on the mesh (novox/hq ADR 0152).
+	//
+	// **A grant, and only a grant.** The bus lets this module publish exactly those tool subjects
+	// and nothing beside them — no event, no subscription, no seat. A module that declares none
+	// calls nothing, which is every module but the console today. ADR 0095 made the control plane
+	// the one caller and deferred this until a consumer asked; the console is that consumer, and a
+	// person's account (design 25 §7) already had the same shape.
+	Invokes []string `json:"invokes,omitempty"`
+
 	// Capabilities the machine must have. A different field from Requires because the remedy
 	// differs: a missing module can be assigned, and a missing capability means the wrong
 	// machine.
@@ -1290,6 +1305,7 @@ func ParseManifest(raw []byte) (Manifest, error) {
 				"%s listens on %d over %q, which is tcp or udp", m.Module, l.Port, p))
 		}
 	}
+	problems = append(problems, invokeProblems(m)...)
 	problems = append(problems, endpointNameProblems(m)...)
 	problems = append(problems, RouteProblems(m)...)
 	for _, port := range m.Guards {
@@ -1766,3 +1782,25 @@ func EndpointPort(m Manifest, name string) (int, bool) {
 	}
 	return 0, false
 }
+
+// invokeProblems judges what a module says it calls (novox/hq ADR 0152).
+//
+// Refused here, in the manifest's words, rather than at the next composition of the bus's user
+// list — where a bad entry would stop the whole file being written for everybody, as a person's
+// malformed grant would have (operator.go). An entry that names a module and no tool is the one
+// mistake worth naming: `shop` reads like a grant to a module's tools and would be a grant to nothing.
+func invokeProblems(m Manifest) []string {
+	var problems []string
+	for _, t := range m.Invokes {
+		if t == "*" {
+			continue
+		}
+		module, tool, named := strings.Cut(t, ".")
+		if !named || !name.MatchString(module) || !toolName.MatchString(tool) {
+			problems = append(problems, fmt.Sprintf(
+				"%s invokes %q, which does not name a tool: a module invokes <module>.<tool>, or "+
+					"* for every tool on the mesh (novox/hq ADR 0152)", m.Module, t))
+		}
+	}
+	return problems
+}

internal/inventory/busrecords.go

@@ -118,6 +118,8 @@ func declaredFor(m catalogue.Manifest, seats map[string]catalogue.SeatDeclaratio
 		// The tools it answers, which is `tools` and not `serves`: the manifest's `serves` is the
 		// facts a consumer needs to reach a provision, a different meaning under a similar word.
 		Serves: m.Tools,
+		// And what it calls (novox/hq ADR 0152) — the console's `*`, nothing else's.
+		Invokes: m.Invokes,
 	}
 	for _, c := range m.Claims {
 		// Every seat with a protocol, the mesh's own included. One that says only who does a job is