Remove a machine's mesh keys and entry when its key is no longer reported (issue 955 F)

modules/gitea/cmd/forge-account-provider/service.go

@@ -66,6 +66,8 @@ type Service struct {
 	keys  map[string]machineKey
 	known string // the forge's host key line, as the machines write it into known_hosts
 
+	bound provider.Bus // the bus the entries are written to (set by Provider)
+
 	making sync.Mutex // one Make at a time: they register keys, and two at once would race each other
 }
 
@@ -85,10 +87,12 @@ func NewService(cfg Config) *Service {
 // Provider is the provider helper answering the consumers over bus. Every consumer is made again every ten minutes,
 // which puts back an account, its team or a key changed by hand.
 func (s *Service) Provider(bus provider.Bus) *provider.Provider {
+	vb := &valuesBus{Bus: bus, s: s, written: map[string][]byte{}}
+	s.bound = vb
 	return provider.New(provider.Options{
 		Node: s.cfg.Node, Module: Module,
 		Offers: map[string]provider.Offer{ProvisionName: {Credential: provider.NoCredential}},
-		Bus:    &valuesBus{Bus: bus, s: s, written: map[string][]byte{}},
+		Bus:    vb,
 		Make:   s.Make, Gone: s.Gone,
 		Every: 10 * time.Minute,
 		Logf:  s.cfg.Log,
@@ -115,6 +119,16 @@ func (s *Service) Make(ctx context.Context, c provider.Consumer) error {
 	}
 	have := s.keysOf(node)
 	if len(have) == 0 {
+		// A key the machine no longer reports is no longer wanted (ADR 0400 §2): the mesh's keys go, the operator's
+		// stay, and the entry that served the machine goes with them.
+		if err := s.accounts.RemoveKeysTitled(ctx, user, forgeaccount.TitlePrefix+node+"."); err != nil {
+			return err
+		}
+		if s.bound != nil {
+			if err := s.bound.Delete(ctx, provider.BucketOf(Module), c.Entry.Key()); err != nil {
+				return err
+			}
+		}
 		return errNoKey{node}
 	}
 	if _, err := s.hostName(); err != nil {

modules/gitea/cmd/forge-account-provider/service_test.go

@@ -415,3 +415,21 @@ func (f *fakeKeys) Watch(handle func(key, op string, value []byte, current bool)
 	return nil
 }
 func (f *fakeKeys) send(key, op string, v []byte, current bool) { f.handle(key, op, v, current) }
+
+func TestADeletedKeyEntryRemovesTheMeshKeyAndTheBoundEntryButNotTheOperatorsKey(t *testing.T) {
+	r := newRig(t)
+	r.bus.bindClient("g14")
+	r.key("g14", "nox", pubA+" nox@g14 (mesh)")
+	r.pass()
+	r.forge.mu.Lock()
+	r.forge.held["agent-g14"] = append(r.forge.held["agent-g14"], map[string]any{"id": int64(99), "title": "my own", "key": pubB})
+	r.forge.mu.Unlock()
+	r.svc.KeyGone("g14.nox")
+	r.pass()
+	if got := r.forge.titles("agent-g14"); len(got) != 1 || got[0] != "my own" {
+		t.Fatalf("keys = %v", got)
+	}
+	if r.bus.has("g14.ssh-client.forge-account") {
+		t.Fatal("the entry still serves a machine whose key is gone")
+	}
+}