The mesh's own verbs are the mesh-controller seat's tools

A seat's protocol lives in the store (migration 0047; seeded additively), a served verb carries its
description and schema, holding a mesh seat requires serving its verbs, a node-scoped seat's tool
carries the node, and the control plane serves status, nodes, node, modules, seats, builds, plan,
assign, unassign, push, build and tools on its seat by running the same commands (novox/hq ADR 0132,
ADR 0154, design 33). A grant of * reaches a role's tools; seat:<seat>.<verb> grants one.
This commit is contained in:
2026-09-30 17:39:38 +02:00
parent 990ef27cd2
commit e9df5dccab
18 changed files with 840 additions and 27 deletions
+2 -1
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@@ -42,7 +42,8 @@ func TestInvokingGrantsNothingButTheCall(t *testing.T) {
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.") {
// A role's tools are tools (ADR 0132); a role's work queue and events are not.
if strings.HasPrefix(p, "mesh.seat.") && !strings.Contains(p, ".tool.") {
t.Errorf("a module that only invokes may publish %q, a seat it neither holds nor uses", p)
}
}
+42 -5
View File
@@ -39,7 +39,11 @@ const (
// Seat is a role on the bus as a principal relates to it: the subjects it accepts, and those it
// emits (novox/hq ADR 0118, design 29 §5).
type Seat struct {
Name string
Name string
// Scope is where the seat has one holder. A node-scoped seat's tool carries the node in its
// subject, because one subject reaching six machines' holders is not an address
// (novox/hq ADR 0132, design 33 §4). Empty reads as mesh.
Scope string
Accepts []string
Emits []string
Serves []string
@@ -197,6 +201,13 @@ func PermissionsFor(p Principal) (Permissions, error) {
// the new bus was refused the publish (2026-09-28).
pub = append(pub, "mesh.mod.*.tool.>")
// **And the mesh's own verbs, as the seat it holds** (novox/hq ADR 0132, ADR 0154):
// `status`, `push`, `assign` are the mesh-controller seat's tools, served by its holder. The
// whole verb namespace of its own seat rather than a list: the list is the seat's protocol,
// which this package mirrors rather than reads, and a verb the seat does not declare is a
// subject nothing publishes.
sub = append(sub, "mesh.seat."+ControllerSeat+".tool.>")
// The two events it reacts to, and its ack subject on the stream they arrive from
// (streams.go). **Each named, not a pattern**: `mesh.mod.*.event.>` would make the
// controller a subscriber to every event in the mesh, and its permission list would stop
@@ -343,7 +354,7 @@ func PermissionsFor(p Principal) (Permissions, error) {
pub = append(pub, seatSubject(s, "event", e))
}
for _, t := range s.Serves {
sub = append(sub, seatSubject(s, "tool", t))
sub = append(sub, seatToolSubject(s, t, p.Node))
}
}
@@ -355,7 +366,7 @@ func PermissionsFor(p Principal) (Permissions, error) {
pub = append(pub, seatSubject(s, "accept", a))
}
for _, t := range s.Serves {
pub = append(pub, seatSubject(s, "tool", t))
pub = append(pub, seatToolSubject(s, t, "*"))
}
}
}
@@ -405,6 +416,18 @@ func seatSubject(s Seat, kind, verb string) string {
return "mesh.seat." + s.Name + "." + kind + "." + verb
}
// seatToolSubject is where a role's tool is asked. Mesh-wide for a mesh-scoped seat; a node-scoped
// seat carries the node it is asked of, because a flat subject would reach every machine's holder
// and the queue group would silently pick a winner (novox/hq ADR 0132, design 33 §4). A holder
// subscribes its own node's; a user publishes any node's (`*`) and names the machine in the subject.
func seatToolSubject(s Seat, verb, node string) string {
base := seatSubject(s, "tool", verb)
if s.Scope == "node" && node != "" {
return base + "." + node
}
return base
}
// consumerStream and consumerDurable are the two halves of a consumer's identity, and they are
// two functions because conflating them was a real bug.
//
@@ -615,13 +638,27 @@ func invokedSubjects(invokes []string) ([]string, error) {
var out []string
for _, t := range invokes {
if t == "*" {
out = append(out, "mesh.mod.*.tool.>")
// Every module's tools and every role's (novox/hq ADR 0132): a role's verb is a tool
// like any other, addressed to the seat instead of a module.
out = append(out, "mesh.mod.*.tool.>", "mesh.seat.*.tool.>")
continue
}
if rest, isSeat := strings.CutPrefix(t, "seat:"); isSeat {
// A role's tool, `seat:<seat>.<verb>`. Both address shapes, because the grant is
// written without knowing the seat's scope: a mesh seat's verb is flat and a node
// seat's carries the machine (design 33 §4).
seat, verb, ok := strings.Cut(rest, ".")
if !ok || seat == "" || verb == "" {
return nil, fmt.Errorf(
"%q does not name a role's tool: one invokes seat:<seat>.<verb>", t)
}
out = append(out, "mesh.seat."+seat+".tool."+verb, "mesh.seat."+seat+".tool."+verb+".*")
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)
"%q does not name a tool: one invokes <module>.<tool>, seat:<seat>.<verb>, or * for every one", t)
}
out = append(out, "mesh.mod."+module+".tool."+tool)
}
+57
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@@ -0,0 +1,57 @@
package broker
import "testing"
// A node-scoped seat's tool carries the node (novox/hq ADR 0132, design 33 §4): two nodes holding one
// node-scoped seat derive two addresses, and a user of the seat may publish any node's.
func TestTwoNodesHoldingOneNodeSeatDeriveTwoToolAddresses(t *testing.T) {
seat := Seat{Name: "node-dns-resolver", Scope: "node", Serves: []string{"lookup"}}
one, _ := PermissionsFor(Principal{Kind: KindModule, Node: "one", Module: "dnsmasq", Holds: []Seat{seat}, PasswordHash: "x"})
two, _ := PermissionsFor(Principal{Kind: KindModule, Node: "two", Module: "dnsmasq", Holds: []Seat{seat}, PasswordHash: "x"})
has(t, one.Subscribe, "mesh.seat.node-dns-resolver.tool.lookup.one")
has(t, two.Subscribe, "mesh.seat.node-dns-resolver.tool.lookup.two")
hasNot(t, one.Subscribe, "mesh.seat.node-dns-resolver.tool.lookup")
hasNot(t, one.Subscribe, "mesh.seat.node-dns-resolver.tool.lookup.two")
user, _ := PermissionsFor(Principal{Kind: KindModule, Node: "three", Module: "asker", Uses: []Seat{seat}, PasswordHash: "x"})
has(t, user.Publish, "mesh.seat.node-dns-resolver.tool.lookup.*")
}
// A mesh-scoped seat's tool stays flat: nothing about it changes.
func TestAMeshSeatsToolIsAddressedToTheSeatAlone(t *testing.T) {
seat := Seat{Name: "git", Scope: "mesh", Serves: []string{"list_repos"}}
holder, _ := PermissionsFor(Principal{Kind: KindModule, Node: "one", Module: "gitea", Holds: []Seat{seat}, PasswordHash: "x"})
has(t, holder.Subscribe, "mesh.seat.git.tool.list_repos")
user, _ := PermissionsFor(Principal{Kind: KindModule, Node: "two", Module: "asker", Uses: []Seat{seat}, PasswordHash: "x"})
has(t, user.Publish, "mesh.seat.git.tool.list_repos")
}
// The controller serves its own seat's verbs and may answer them (novox/hq ADR 0154).
func TestTheControllerServesItsSeatsToolsAndMayAnswer(t *testing.T) {
perms, err := PermissionsFor(Principal{Kind: KindController, PasswordHash: "x"})
if err != nil {
t.Fatal(err)
}
has(t, perms.Subscribe, "mesh.seat.mesh-controller.tool.>")
if !perms.AllowResponses {
t.Fatal("the controller serves tools and may not answer one")
}
}
// A grant to every tool reaches a role's tools too, and a role's tool is granted by name.
func TestAGrantReachesARolesTools(t *testing.T) {
all, _ := PermissionsFor(Principal{Kind: KindModule, Node: "desk", Module: "mesh-console", Invokes: []string{"*"}, PasswordHash: "x"})
has(t, all.Publish, "mesh.seat.*.tool.>")
one, err := PermissionsFor(Principal{Kind: KindPerson, Module: "jo", Invokes: []string{"seat:mesh-controller.status"}, PasswordHash: "x"})
if err != nil {
t.Fatal(err)
}
has(t, one.Publish, "mesh.seat.mesh-controller.tool.status")
hasNot(t, one.Publish, "mesh.seat.mesh-controller.tool.push")
hasNot(t, one.Publish, "mesh.mod.*.tool.>")
if _, err := PermissionsFor(Principal{Kind: KindPerson, Module: "jo", Invokes: []string{"seat:mesh-controller"}, PasswordHash: "x"}); err == nil {
t.Fatal("a role grant naming no verb was accepted")
}
}
+1 -1
View File
@@ -25,7 +25,7 @@ accounts {
users = [
{ user: "controller", password: "$2a$11$cccccccccccccccccccccc", permissions: {
publish: { allow: ["$JS.ACK.CONTROL.controller.>", "$JS.ACK.EVENTS.controller.>", "$JS.API.>", "_INBOX.enrol.>", "mesh.control.>", "mesh.mod.*.tool.>", "mesh.node.>", "mesh.seat.mesh-build-machine.accept.>", "mesh.seat.mesh-controller.event.applied", "mesh.seat.mesh-controller.event.built-before", "mesh.seat.mesh-controller.event.refused"] }
subscribe: { allow: ["$JS.API.>", "_DELIVER.controller", "_DELIVER.controller.>", "_INBOX.controller.>", "mesh.control.>", "mesh.mod.gitea.event.pull.merged", "mesh.mod.mesh-catalog.event.catching-up", "mesh.mod.mesh-catalog.event.upgraded", "mesh.seat.mesh-build-machine.event.built"] }
subscribe: { allow: ["$JS.API.>", "_DELIVER.controller", "_DELIVER.controller.>", "_INBOX.controller.>", "mesh.control.>", "mesh.mod.gitea.event.pull.merged", "mesh.mod.mesh-catalog.event.catching-up", "mesh.mod.mesh-catalog.event.upgraded", "mesh.seat.mesh-build-machine.event.built", "mesh.seat.mesh-controller.tool.>"] }
allow_responses: { max: 1, ttl: "1m" }
} }
{ user: "enrol.one", password: "$2a$11$eeeeeeeeeeeeeeeeeeeeee", permissions: {
+3 -2
View File
@@ -252,8 +252,8 @@ 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).
// Invokes are the tools this module calls, each `<module>.<tool>` or a role's `seat:<seat>.<verb>`,
// or the single entry `*` for every tool on the mesh (novox/hq ADR 0152, ADR 0154).
//
// **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
@@ -1795,6 +1795,7 @@ func invokeProblems(m Manifest) []string {
if t == "*" {
continue
}
t = strings.TrimPrefix(t, "seat:")
module, tool, named := strings.Cut(t, ".")
if !named || !name.MatchString(module) || !toolName.MatchString(tool) {
problems = append(problems, fmt.Sprintf(
+17 -3
View File
@@ -37,7 +37,9 @@ type Seat struct {
// today — which the bus refuses, because a namespace belongs to who it is named for.
Accepts []string
Emits []string
Serves []string
// Serves carries each verb in full — name, description, schema — because a role's tools are the
// mesh's to define and an agent's to call (novox/hq ADR 0132, design 33 §2).
Serves []Verb
// Decision is the record that made it a seat.
Decision string
}
@@ -51,8 +53,12 @@ var defaultSeats = []Seat{
// The control plane states what it did under the seat it holds (novox/hq ADR 0134): a role's
// events belong to the role, so they keep their address while the holder is replaced. No accepts,
// so no work queue is raised for it — only what its holder may say.
{Name: "mesh-controller", Scope: ScopeMesh, Decision: "novox/hq ADR 0079",
Emits: []string{"applied", "refused", "built-before"}},
// And it serves the mesh's own verbs as the seat's tools (novox/hq ADR 0154): `status`, `push`,
// `assign` and the rest are a role's interface, not a container's, and stay addressable while
// the control plane is replaced.
{Name: ControllerSeatName, Scope: ScopeMesh, Decision: "novox/hq ADR 0079",
Emits: []string{"applied", "refused", "built-before"},
Serves: ControllerVerbs},
{Name: "mesh-store", Scope: ScopeMesh, Delivers: "postgres-database", Decision: "novox/hq ADR 0079"},
// **Delivers the mesh's own bus, not `amqp`.** Those were the same word until
// ADR 0127 separated them: `amqp` is a backing service a module may require, and this seat is
@@ -269,6 +275,14 @@ func CanHold(m Manifest, seat Seat) error {
return fmt.Errorf("%s claims %s, whose holder answers for %q, and %s does not provide %q at %s scope",
m.Module, seat.Name, seat.Delivers, m.Module, seat.Delivers, seat.Scope)
}
// **Serving the seat's tools is a condition of holding it** (novox/hq ADR 0132). A holder that
// does not answer what the role promises is every caller's timeout, found at registration and
// at handover instead, naming the verbs rather than the fact that something is missing.
if missing := unservedVerbs(m.Tools, seat.Serves); len(missing) > 0 {
return fmt.Errorf("%s claims %s but does not serve %s, which that seat's protocol promises "+
"(novox/hq ADR 0132) — a holder lists every verb its seat declares under tools",
m.Module, seat.Name, strings.Join(missing, ", "))
}
return nil
}
+6 -5
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@@ -38,8 +38,9 @@ type SeatDeclaration struct {
Accepts []string `json:"accepts,omitempty"`
// Emits are the verbs the holder publishes: 1:many, nobody obliged to act.
Emits []string `json:"emits,omitempty"`
// Serves are the verbs the holder answers: request and reply, awaited.
Serves []string `json:"serves,omitempty"`
// Serves are the verbs the holder answers: request and reply, awaited. A bare name, or the
// verb in full with its schema (novox/hq ADR 0132).
Serves []Verb `json:"serves,omitempty"`
// RetainSeconds is how long the inbound backlog survives with no holder, zero for the
// mesh's default. Retention belongs to whoever owns the namespace (design 29 §3) — a seat
@@ -62,7 +63,7 @@ func (s SeatDeclaration) At() string {
func (s SeatDeclaration) verbs() []string {
out := append([]string{}, s.Accepts...)
out = append(out, s.Emits...)
return append(out, s.Serves...)
return append(out, VerbNames(s.Serves)...)
}
// declaredSeatProblems is what one manifest can be judged on alone.
@@ -228,8 +229,8 @@ func unserved(m Manifest, s SeatDeclaration) []string {
}
var missing []string
for _, t := range s.Serves {
if !has[t] {
missing = append(missing, t)
if !has[t.Name] {
missing = append(missing, t.Name)
}
}
return missing
+1 -1
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@@ -13,7 +13,7 @@ func problemsFor(t *testing.T, shelf Shelf) string {
func telegram() Manifest {
return Manifest{Module: "telegram", Tools: []string{"status"}, DefinesSeats: []SeatDeclaration{{
Name: "telegram-sender", Scope: ScopeMesh,
Accepts: []string{"send"}, Emits: []string{"delivered", "failed"}, Serves: []string{"status"},
Accepts: []string{"send"}, Emits: []string{"delivered", "failed"}, Serves: []Verb{{Name: "status"}},
}}, Claims: []Claim{{Name: "telegram-sender", Scope: ScopeMesh}}}
}
+133
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@@ -0,0 +1,133 @@
package catalogue
import (
"bytes"
"encoding/json"
"fmt"
)
// A Verb is one tool a role serves: its name, what it does, and the schema of its arguments and of
// its answer (novox/hq ADR 0132, design 33 §2).
//
// **A name alone is not callable by something that has never seen the mesh before**, which is the
// whole population a tool surface exists for. So a seat's protocol carries the definition, in the
// form an agent protocol already uses — a JSON schema for the input — so nothing translates between
// a seat's idea of an argument and the caller's.
//
// A manifest may still write a bare verb name (`"serves": ["price"]`); that is a Verb with only a
// name, and the module's runtime answers `tools` with the rest. The two forms read into one type so
// nothing downstream cares which was written.
type Verb struct {
Name string `json:"name"`
Description string `json:"description,omitempty"`
Input map[string]any `json:"input,omitempty"`
Output map[string]any `json:"output,omitempty"`
}
func (v *Verb) UnmarshalJSON(raw []byte) error {
trimmed := bytes.TrimSpace(raw)
if len(trimmed) > 0 && trimmed[0] == '"' {
var name string
if err := json.Unmarshal(trimmed, &name); err != nil {
return err
}
*v = Verb{Name: name}
return nil
}
// Strictly, like the manifest around it: a misspelt key in a tool's definition would otherwise
// describe a tool nobody can call and refuse nothing.
type plain Verb
var p plain
decoder := json.NewDecoder(bytes.NewReader(trimmed))
decoder.DisallowUnknownFields()
if err := decoder.Decode(&p); err != nil {
return fmt.Errorf("a served verb is a name or {name, description, input, output}: %w", err)
}
if p.Name == "" {
return fmt.Errorf("a served verb has no name: %s", trimmed)
}
*v = Verb(p)
return nil
}
// VerbNames are the names alone, for the grants and the checks that care about nothing else.
func VerbNames(verbs []Verb) []string {
out := make([]string, 0, len(verbs))
for _, v := range verbs {
out = append(out, v.Name)
}
return out
}
// ControllerSeatName is the seat the control plane holds, whose tools are the mesh's own verbs.
const ControllerSeatName = "mesh-controller"
// ControllerVerbs are the mesh's own verbs, as the `mesh-controller` seat's tools (novox/hq ADR 0154).
//
// **The same function the command line calls, and nothing the tool adds** (ADR 0035): each of these
// is a command the controller's binary already answers, run by the holder of the seat with the
// arguments below and answered with what the command printed. A verb here is a contract every future
// holder must implement, which is why the list is short and made of what an operator asks weekly.
// Additive within a version (design 33 §7); a verb that would break a caller takes a new version.
var ControllerVerbs = []Verb{
{Name: "tools", Description: "Every seat's tools, from the mesh's own records: what each role " +
"answers, whether or not its holder is up. The mesh's own verbs are the mesh-controller seat's.",
Input: schema(nil, nil)},
{Name: "status", Description: "What is wrong, what is quiet, what is out of date, and which " +
"machines are behind what the mesh would send them.",
Input: schema(nil, nil)},
{Name: "nodes", Description: "Every machine the mesh knows, with whether it is converged or adopted.",
Input: schema(nil, nil)},
{Name: "node", Description: "What one machine reported it can do, what it is assigned, and why.",
Input: schema(map[string]string{"node": "the machine's name"}, []string{"node"})},
{Name: "modules", Description: "Every module the mesh holds: version, the commit it was built from, " +
"and which machines run it.",
Input: schema(nil, nil)},
{Name: "seats", Description: "Every seat the mesh defines, what it delivers, and who holds it.",
Input: schema(nil, nil)},
{Name: "builds", Description: "What has been built lately and what came of it, for every module or for one.",
Input: schema(map[string]string{"module": "one module's name; every module when absent"}, nil)},
{Name: "plan", Description: "What one machine would run, and why: the declaration the mesh would send it.",
Input: schema(map[string]string{"node": "the machine's name"}, []string{"node"})},
{Name: "assign", Description: "Put a module on a machine. Refused with the mesh's own words when it cannot resolve there.",
Input: schema(map[string]string{"node": "the machine's name", "module": "the module's name"}, []string{"node", "module"})},
{Name: "unassign", Description: "Take a module off a machine.",
Input: schema(map[string]string{"node": "the machine's name", "module": "the module's name"}, []string{"node", "module"})},
{Name: "push", Description: "Send a machine everything it should be — or every machine that is behind, when no machine is named.",
Input: schema(map[string]string{"node": "the machine's name; every machine behind when absent"}, nil)},
{Name: "build", Description: "Have the build machine build a repository and record what came out.",
Input: schema(map[string]string{
"repository": "the repository's URL, or its path on the forge holding the git seat",
"path": "the module's directory inside it (optional)",
"ref": "the branch, tag or commit to build (optional)",
}, []string{"repository"})},
}
// schema is a JSON schema for an object of string properties, which is every argument the verbs
// above take. Kept small on purpose: a schema an agent cannot read is a tool it cannot call.
func schema(properties map[string]string, required []string) map[string]any {
props := map[string]any{}
for name, description := range properties {
props[name] = map[string]any{"type": "string", "description": description}
}
out := map[string]any{"type": "object", "properties": props}
if len(required) > 0 {
out["required"] = required
}
return out
}
// unservedVerbs is what a seat promises and a claimant's `tools` does not answer.
func unservedVerbs(tools []string, promised []Verb) []string {
has := map[string]bool{}
for _, t := range tools {
has[t] = true
}
var missing []string
for _, v := range promised {
if !has[v.Name] {
missing = append(missing, v.Name)
}
}
return missing
}
+72
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@@ -0,0 +1,72 @@
package catalogue
import (
"strings"
"testing"
)
// A served verb is written as a bare name or in full, and both read into one type (novox/hq ADR 0132).
func TestAServedVerbIsANameOrADefinition(t *testing.T) {
m, err := ParseManifest([]byte(`{"module":"till","version":"1","tools":["price","refund"],` +
`"seats":[{"name":"shop-till","serves":["price",{"name":"refund","description":"give it back",` +
`"input":{"type":"object","properties":{"order":{"type":"string"}}}}]}],` +
`"claims":[{"name":"shop-till","scope":"mesh"}]}`))
if err != nil {
t.Fatal(err)
}
got := m.DefinesSeats[0].Serves
if len(got) != 2 || got[0].Name != "price" || got[1].Name != "refund" || got[1].Description != "give it back" {
t.Fatalf("verbs not read: %+v", got)
}
if got[1].Input["type"] != "object" {
t.Fatalf("the schema did not travel with the verb: %+v", got[1].Input)
}
}
// A misspelt key inside a verb's definition is refused, like one anywhere else in the manifest.
func TestAVerbWithAnUnknownKeyIsRefused(t *testing.T) {
_, err := ParseManifest([]byte(`{"module":"till","version":"1",` +
`"seats":[{"name":"shop-till","serves":[{"name":"price","descripton":"typo"}]}]}`))
if err == nil || !strings.Contains(err.Error(), "descripton") {
t.Fatalf("a verb with a misspelt key was accepted: %v", err)
}
}
// Holding a mesh seat that serves verbs requires serving them, and the refusal names the verbs.
func TestHoldingAMeshSeatRequiresServingItsVerbs(t *testing.T) {
was := Seats()
t.Cleanup(func() { UseSeats(was) })
UseSeats([]Seat{{Name: "mesh-controller", Scope: ScopeMesh, Decision: "test",
Serves: []Verb{{Name: "status"}, {Name: "push"}}}})
seat, _ := SeatNamed("mesh-controller")
partial := Manifest{Module: "a-controller", Tools: []string{"status"},
Claims: []Claim{{Name: "mesh-controller", Scope: ScopeMesh}}}
err := CanHold(partial, seat)
if err == nil || !strings.Contains(err.Error(), "does not serve push") {
t.Fatalf("a holder missing a verb was not refused by name: %v", err)
}
whole := Manifest{Module: "a-controller", Tools: []string{"status", "push"},
Claims: []Claim{{Name: "mesh-controller", Scope: ScopeMesh}}}
if err := CanHold(whole, seat); err != nil {
t.Fatalf("a holder serving every verb was refused: %v", err)
}
}
// The mesh's own verbs are declared in full: an agent cannot call a name without a schema.
func TestEveryControllerVerbIsDescribedWithASchema(t *testing.T) {
seen := map[string]bool{}
for _, v := range ControllerVerbs {
if v.Description == "" || v.Input == nil || v.Input["type"] != "object" {
t.Errorf("%s: no description or no object schema", v.Name)
}
if seen[v.Name] {
t.Errorf("%s declared twice", v.Name)
}
seen[v.Name] = true
}
seat, _ := SeatNamed(ControllerSeatName)
if len(seat.Serves) != len(ControllerVerbs) {
t.Fatalf("the compiled mesh-controller seat serves %d verbs, the table has %d", len(seat.Serves), len(ControllerVerbs))
}
}
+3 -2
View File
@@ -137,7 +137,8 @@ func declaredFor(m catalogue.Manifest, seats map[string]catalogue.SeatDeclaratio
}
func asSeat(s catalogue.SeatDeclaration) broker.Seat {
return broker.Seat{Name: s.Name, Accepts: s.Accepts, Emits: s.Emits, Serves: s.Serves}
return broker.Seat{Name: s.Name, Scope: s.Scope, Accepts: s.Accepts, Emits: s.Emits,
Serves: catalogue.VerbNames(s.Serves)}
}
// MeshSeats are the mesh's own seats that carry a protocol, as the bus needs them: what to make a work
@@ -146,7 +147,7 @@ func MeshSeats() []broker.DeclaredSeat {
var out []broker.DeclaredSeat
for _, s := range catalogue.SeatsWithAProtocol() {
out = append(out, broker.DeclaredSeat{
Name: s.Name, Accepts: s.Accepts, Emits: s.Emits, Serves: s.Serves,
Name: s.Name, Accepts: s.Accepts, Emits: s.Emits, Serves: catalogue.VerbNames(s.Serves),
})
}
return out
@@ -0,0 +1,12 @@
-- A seat's protocol lives in the store, not in the binary (novox/hq ADR 0129, ADR 0132, design 33 §2).
--
-- ADR 0122 moved the seat set into this table with name, scope, delivers and decision, and the
-- protocol — what a role accepts, emits and serves — stayed compiled into the control plane and was
-- merged in as a row was read. Discovery that reads a binary disagrees with the mesh the moment the
-- two are on different versions, and a tool without a schema is not something an agent can call. So
-- the three halves become columns: accepts and emits as lists of verbs, serves as the verbs in full
-- ({name, description, input, output}). Seeded from the compiled defaults where a row has none,
-- additively thereafter (a verb a release adds joins the row; nothing is taken away).
alter table seat add column accepts jsonb not null default '[]'::jsonb;
alter table seat add column emits jsonb not null default '[]'::jsonb;
alter table seat add column serves jsonb not null default '[]'::jsonb;
+115 -7
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@@ -2,6 +2,7 @@ package inventory
import (
"context"
"encoding/json"
"fmt"
"github.com/novox/mesh-controller/internal/catalogue"
@@ -17,7 +18,7 @@ import (
// Seats is every seat the mesh defines, read from the store.
func (i *Inventory) Seats(ctx context.Context) ([]catalogue.Seat, error) {
rows, err := i.store.Pool().Query(ctx,
`select name, scope, delivers, decided from seat order by name`)
`select name, scope, delivers, decided, accepts, emits, serves from seat order by name`)
if err != nil {
return nil, err
}
@@ -26,9 +27,21 @@ func (i *Inventory) Seats(ctx context.Context) ([]catalogue.Seat, error) {
var seats []catalogue.Seat
for rows.Next() {
var s catalogue.Seat
if err := rows.Scan(&s.Name, &s.Scope, &s.Delivers, &s.Decision); err != nil {
var accepts, emits, serves []byte
if err := rows.Scan(&s.Name, &s.Scope, &s.Delivers, &s.Decision, &accepts, &emits, &serves); err != nil {
return nil, err
}
// The protocol, from the row (novox/hq ADR 0132). A row that predates the columns has empty
// lists, and UseSeats keeps the compiled protocol for it until the next seeding fills them.
if err := json.Unmarshal(accepts, &s.Accepts); err != nil {
return nil, fmt.Errorf("seat %s: accepts: %w", s.Name, err)
}
if err := json.Unmarshal(emits, &s.Emits); err != nil {
return nil, fmt.Errorf("seat %s: emits: %w", s.Name, err)
}
if err := json.Unmarshal(serves, &s.Serves); err != nil {
return nil, fmt.Errorf("seat %s: serves: %w", s.Name, err)
}
seats = append(seats, s)
}
return seats, rows.Err()
@@ -41,21 +54,116 @@ func (i *Inventory) Seats(ctx context.Context) ([]catalogue.Seat, error) {
// exactly as it is, so an operator's rename in the table is not undone by the next deploy putting
// the old name back. What a release removes from the defaults is not deleted here either; retiring a
// seat is its own decision, not a silent consequence of it dropping out of the binary.
//
// **The protocol is seeded additively** (novox/hq ADR 0132, design 33 §7). A row that has none takes
// the compiled protocol whole — that is the compiled fallback becoming data, once. A row that has one
// gains any verb the defaults name and it lacks, and loses nothing: a seat's tools are an interface,
// additive within a version, and a verb an operator added to the row is theirs to keep.
func (i *Inventory) SeedSeats(ctx context.Context, defaults []catalogue.Seat) (int, error) {
var added int
for _, s := range defaults {
tag, err := i.store.Pool().Exec(ctx,
`insert into seat (name, scope, delivers, decided) values ($1, $2, $3, $4)
on conflict (name) do nothing`,
s.Name, s.Scope, s.Delivers, s.Decision)
accepts, emits, serves, err := protocolJSON(s)
if err != nil {
return added, err
}
added += int(tag.RowsAffected())
tag, err := i.store.Pool().Exec(ctx,
`insert into seat (name, scope, delivers, decided, accepts, emits, serves)
values ($1, $2, $3, $4, $5, $6, $7)
on conflict (name) do nothing`,
s.Name, s.Scope, s.Delivers, s.Decision, accepts, emits, serves)
if err != nil {
return added, err
}
if n := int(tag.RowsAffected()); n > 0 {
added += n
continue
}
if err := i.widenProtocol(ctx, s); err != nil {
return added, err
}
}
return added, nil
}
// widenProtocol adds to a seat's row whatever the defaults name and the row lacks, by verb name.
func (i *Inventory) widenProtocol(ctx context.Context, s catalogue.Seat) error {
var accepts, emits, serves []byte
if err := i.store.Pool().QueryRow(ctx,
`select accepts, emits, serves from seat where name = $1`, s.Name).Scan(&accepts, &emits, &serves); err != nil {
return err
}
var row catalogue.Seat
if err := json.Unmarshal(accepts, &row.Accepts); err != nil {
return err
}
if err := json.Unmarshal(emits, &row.Emits); err != nil {
return err
}
if err := json.Unmarshal(serves, &row.Serves); err != nil {
return err
}
changed := false
row.Accepts, changed = union(row.Accepts, s.Accepts, changed)
row.Emits, changed = union(row.Emits, s.Emits, changed)
have := map[string]bool{}
for _, v := range row.Serves {
have[v.Name] = true
}
for _, v := range s.Serves {
if !have[v.Name] {
row.Serves = append(row.Serves, v)
changed = true
}
}
if !changed {
return nil
}
a, e, sv, err := protocolJSON(row)
if err != nil {
return err
}
_, err = i.store.Pool().Exec(ctx,
`update seat set accepts = $2, emits = $3, serves = $4 where name = $1`, s.Name, a, e, sv)
return err
}
func union(have, want []string, changed bool) ([]string, bool) {
seen := map[string]bool{}
for _, h := range have {
seen[h] = true
}
for _, w := range want {
if !seen[w] {
have = append(have, w)
seen[w] = true
changed = true
}
}
return have, changed
}
func protocolJSON(s catalogue.Seat) (accepts, emits, serves []byte, err error) {
if accepts, err = json.Marshal(orEmpty(s.Accepts)); err != nil {
return
}
if emits, err = json.Marshal(orEmpty(s.Emits)); err != nil {
return
}
verbs := s.Serves
if verbs == nil {
verbs = []catalogue.Verb{}
}
serves, err = json.Marshal(verbs)
return
}
func orEmpty(s []string) []string {
if s == nil {
return []string{}
}
return s
}
// Aliases is every former seat name and the seat it now resolves to (novox/hq ADR 0122).
func (i *Inventory) Aliases(ctx context.Context) (map[string]string, error) {
rows, err := i.store.Pool().Query(ctx, `select alias, seat from seat_alias`)
+76
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@@ -0,0 +1,76 @@
package link
import (
"context"
"encoding/json"
"fmt"
"log"
"time"
"github.com/nats-io/nats.go"
)
// A role's tools, served by its holder (novox/hq ADR 0132, ADR 0154).
//
// The mesh's own verbs — `status`, `push`, `assign` — are the mesh-controller seat's tools, and the
// control plane is that seat's holder. So it answers them here, on the seat's subjects, the way a
// module's runtime answers a module's: one request, one reply on the asker's own inbox, `{result}` or
// `{error}`. Nothing about the transport is the command's business; a handler is a function of its
// arguments and gets the same answer the command line prints.
// ToolHandler answers one call of a role's tool. What it returns is marshalled as the result; an
// error is the tool answering with one, which is an answer and not a timeout.
type ToolHandler func(ctx context.Context, args json.RawMessage) (any, error)
// SeatToolSubject is where a mesh-scoped seat's tool is asked (design 33 §4).
func SeatToolSubject(seat, verb string) string { return "mesh.seat." + seat + ".tool." + verb }
// HandlerTimeout bounds one answer. A verb that runs a command — a push, a build with no wait —
// answers in seconds; anything that has not in this long is said to have not answered.
const HandlerTimeout = 5 * time.Minute
// ServeSeatTools binds every handler on its seat's subject until stopped. A queue group per seat, so
// a second holder during a handover shares the calls rather than both answering one.
func (b OverNATS) ServeSeatTools(seat string, handlers map[string]ToolHandler, logger *log.Logger) (func(), error) {
var subs []*nats.Subscription
stop := func() {
for _, s := range subs {
_ = s.Unsubscribe()
}
}
for verb, handle := range handlers {
verb, handle := verb, handle
subject := SeatToolSubject(seat, verb)
sub, err := b.Conn.QueueSubscribe(subject, "seat."+seat, func(msg *nats.Msg) {
// Its own goroutine per call: a slow `push` must not hold up a `status` asked beside it,
// and the library would otherwise run handlers one after another.
go func() {
ctx, cancel := context.WithTimeout(context.Background(), HandlerTimeout)
defer cancel()
args := json.RawMessage(msg.Data)
if len(args) == 0 {
args = json.RawMessage(`{}`)
}
var reply []byte
result, err := handle(ctx, args)
if err != nil {
reply, _ = json.Marshal(map[string]any{"error": err.Error()})
} else if reply, err = json.Marshal(map[string]any{"result": result}); err != nil {
reply, _ = json.Marshal(map[string]any{"error": "the answer could not be written as JSON: " + err.Error()})
}
if err := msg.Respond(reply); err != nil && logger != nil {
logger.Printf("%s: could not answer: %v", subject, err)
}
}()
})
if err != nil {
stop()
return nil, fmt.Errorf("serving %s: %w", subject, err)
}
subs = append(subs, sub)
}
if logger != nil {
logger.Printf("serving %d tool(s) of the %s seat", len(handlers), seat)
}
return stop, nil
}