An assignment issues its bus credential, a push refuses one nobody issued, and what reads a secret restarts on it (hq issue 203)

`assign` recorded a module and `push` sealed a random own secret where its bus credential belongs;
the process crash-looped until a person ran `module issue` and pushed again, and the only warning was
one line in a list printed on every push. Now assigning a module that declares a broker secret issues
the credential in the same act — kept when one exists, so re-assigning rotates nothing — and when the
bus cannot be reached from here the assignment says which verb to run. A push never seals a
placeholder in a credential's place: a module whose bus user is unminted is refused by name, with the
verb. The control plane's own user is the installer's, seeded at genesis, which the test now says.

And what reads one of a module's own secrets is restarted when it changes — composed for a container
or daemon that names the secret's path in its volumes, environment or env-files, so a manifest need
not say it: the build machine ran on an hour-old credential because its manifest restarted it on its
environment file alone (issue 206). A scheduled or run-once process is left alone; it reads afresh.

cmd/mesh-controller/acts.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"fmt"
+	"github.com/novox/mesh-controller/internal/broker"
 	"sort"
 	"strings"
 
@@ -67,6 +68,13 @@ func assign(ctx context.Context, open *stores, node, module string) (string, err
 	for _, line := range settled {
 		said += "\n  " + line
 	}
+	// Its bus credential, in the same act (novox/hq issue 203): an assignment pushed before its
+	// credential exists delivers a process that cannot authenticate and crash-loops until somebody
+	// runs a second verb and a second push. Issued here when the module speaks on the bus and has
+	// no credential yet; kept when it has one, so re-assigning rotates nothing.
+	if line := issueOnAssign(ctx, open, node, module); line != "" {
+		said += "\n  " + line
+	}
 	plan, _, err := planFor(ctx, open, node)
 	if err != nil {
 		// Kept, and still refused. Both halves are the answer, and the rest of the mesh is still
@@ -152,3 +160,33 @@ func blockedElsewhere(ctx context.Context, open *stores, except string) string {
 	out.WriteString("\nThis may or may not be what just changed — it is what is true now.")
 	return out.String()
 }
+
+// issueOnAssign gives a newly assigned module its bus credential, the way `module issue` does, and
+// says what it did in one line. Nothing for a module that declares no broker secret; nothing for one
+// whose user is already minted (a credential is rotated on purpose, never by re-assigning); and when
+// the bus cannot be reached from here, the line names the verb and the push that would refuse the
+// module until it is run — never a silent placeholder (novox/hq issue 203).
+func issueOnAssign(ctx context.Context, open *stores, node, module string) string {
+	inv := open.inventory
+	shelf, err := inv.Catalogue(ctx)
+	if err != nil {
+		return ""
+	}
+	m, known := shelf[module]
+	if !known || mayIssue(m) != nil {
+		return ""
+	}
+	user := broker.Principal{Kind: broker.KindModule, Node: node, Module: module}.Username()
+	if _, minted, err := inv.BusUserHash(ctx, user); err != nil || minted {
+		return ""
+	}
+	busAddress, err := broker.BusAddress()
+	if err == nil {
+		err = issueOnTheNewBus(ctx, inv, m, node, busAddress)
+	}
+	if err != nil {
+		return fmt.Sprintf("its bus credential is not issued (%v): `module issue %s --node %s` first — "+
+			"`push %s` refuses to send %s until it is", err, module, node, node, module)
+	}
+	return fmt.Sprintf("its bus credential is issued and sealed to %s, and arrives with the push", node)
+}

cmd/mesh-controller/addresses_test.go

@@ -175,6 +175,12 @@ func TestTheControlPlaneIsToldWhereTheNodePutTheStoreAndTheBroker(t *testing.T)
 		Guards: []int{15672},
 		Resources: []map[string]any{{"id": "server", "type": "container", "name": "mesh-broker",
 			"ports": []any{"5671:5671", "5672:5672", "127.0.0.1:15672:15672"}, "image": "mq@" + aDigest}}})
+	// The control plane's own bus user is the installer's, seeded at genesis before the controller
+	// runs (SeedBusUser); without it a push now refuses the credential nobody issued (issue 203).
+	if err := open.inventory.SeedBusUser(ctx, inventory.BusUser{Username: "anchor.mesh-controller",
+		Kind: inventory.BusController, Node: "anchor", Module: "mesh-controller"}, "bootstrap"); err != nil {
+		t.Fatal(err)
+	}
 	if _, err := assign(ctx, open, "anchor", "mesh-controller"); err != nil {
 		t.Fatal(err)
 	}

cmd/mesh-controller/credential_on_assign_test.go

@@ -0,0 +1,90 @@
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// A fresh assignment is pushed before its credential exists (novox/hq issue 203): `assign` recorded
+// the module, `push` sealed a random own secret where the bus credential belongs, and the process
+// crash-looped until a person ran `module issue` and pushed again. Now assigning a module that speaks
+// on the bus issues its credential in the same act — or, when the bus cannot be reached from here,
+// says which verb to run — and a push never seals a placeholder in a credential's place.
+
+func aTalker() catalogue.Manifest {
+	return catalogue.Manifest{Module: "talker", Version: "1",
+		OwnSecrets: catalogue.OwnSecrets{"broker": {Path: "/var/lib/mesh/talker/broker"}},
+		Resources: []map[string]any{
+			{"id": "state", "type": "directory", "path": "/var/lib/mesh/talker", "mode": "0700"},
+		}}
+}
+
+func TestAssigningAModuleThatSpeaksOnTheBusNamesItsCredential(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, aTalker())
+
+	// No bus is known to this process, so the credential cannot be issued here: the assignment
+	// stands and says exactly what must happen before a push — never silently.
+	said, err := assign(ctx, open, "laptop", "talker")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(said, "module issue talker --node laptop") {
+		t.Fatalf("an assignment whose credential could not be issued does not name the verb:\n%s", said)
+	}
+
+	// And the push refuses to send it, naming the same verb, rather than sealing a placeholder.
+	plan, settings, err := planFor(ctx, open, "laptop")
+	if err != nil {
+		t.Fatal(err)
+	}
+	_, err = declarationFor(ctx, open, "laptop", plan, settings)
+	if err == nil {
+		t.Fatal("a push sealed a placeholder where talker's bus credential belongs")
+	}
+	if !strings.Contains(err.Error(), "module issue talker --node laptop") || !strings.Contains(err.Error(), "issue 203") {
+		t.Fatalf("the refusal does not say what to run: %v", err)
+	}
+
+	// Once the user is minted, the push goes on to the credential the mesh sealed, and re-assigning
+	// does not mint again: a credential rotates on purpose, never by habit.
+	if _, err := open.inventory.MintBusPassword(ctx, inventory.BusUser{
+		Username: "laptop.talker", Kind: inventory.BusModule, Node: "laptop", Module: "talker"}); err != nil {
+		t.Fatal(err)
+	}
+	hash, _, err := open.inventory.BusUserHash(ctx, "laptop.talker")
+	if err != nil {
+		t.Fatal(err)
+	}
+	said, err = assign(ctx, open, "laptop", "talker")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.Contains(said, "module issue") {
+		t.Fatalf("a module with a minted credential was told to issue one:\n%s", said)
+	}
+	again, _, err := open.inventory.BusUserHash(ctx, "laptop.talker")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if again != hash {
+		t.Fatal("re-assigning rotated the credential")
+	}
+}
+
+// A module that declares no broker secret is left alone: nothing to issue, nothing said.
+func TestAssigningAModuleThatDoesNotSpeakSaysNothingOfCredentials(t *testing.T) {
+	open := aMesh(t)
+	register(t, open, helloWeb())
+	said, err := assign(t.Context(), open, "laptop", "hello-web")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.Contains(said, "credential") {
+		t.Fatalf("a module without a broker secret was told about credentials:\n%s", said)
+	}
+}

cmd/mesh-controller/plan.go

@@ -533,6 +533,23 @@ func renderingFor(ctx context.Context, open *stores, node string,
 			var sealed string
 			var err error
 			if choosing == Allocating {
+				// **The broker credential is never invented here** (novox/hq issue 203). Every other
+				// own secret is the mesh's to make — a password nobody else knows — but this one
+				// is an account on the bus, minted by `module issue` and sealed by it; a push that
+				// made a random one would deliver a file the process cannot read and report the
+				// machine applied. Refused by name, with the verb.
+				if name == "broker" {
+					user := broker.Principal{Kind: broker.KindModule, Node: node, Module: m.Module}.Username()
+					if _, minted, err := inv.BusUserHash(ctx, user); err != nil {
+						return catalogue.Rendering{}, inventory.Node{}, err
+					} else if !minted {
+						return catalogue.Rendering{}, inventory.Node{}, fmt.Errorf(
+							"%s on %s has no bus credential: nothing was issued for %s, and a push "+
+								"would seal a placeholder its process cannot read (novox/hq issue 203). "+
+								"`module issue %s --node %s`, then push again",
+							m.Module, node, user, m.Module, node)
+					}
+				}
 				sealed, err = inv.SecretForModule(ctx, node, m.Module, name)
 			} else {
 				var held bool