A module depends on the node seats that apply its resources (hq ADR 0207)

Seed node-package-manager and node-container-runtime. Derive each module's dependencies from its declared service, package and container resources; judge them over the node's whole set, exempting the foundation. Refuse at assign (several modules may go on as one act) and at unassign of the last holder; report at composition in status, behind one switch.
2026-10-04 12:34:11 +02:00
parent 912e9f4e85
commit 10f948e970
16 changed files with 916 additions and 41 deletions
@@ -0,0 +1,147 @@
+package main
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// Defends novox/hq ADR 0207 at the controller's acts: `assign` refuses a module whose resources a
+// seat nothing on the node holds applies, `unassign` refuses taking the last holder from under its
+// dependents, and `status` reports what composition does not yet refuse.
+
+func serviceManagerHolder() catalogue.Manifest {
+	return catalogue.Manifest{Module: "systemd", Version: "1",
+		Claims: []catalogue.Claim{{Name: catalogue.ServiceManagerSeat, Scope: catalogue.ScopeNode,
+			Serves: []string{"units", "status", "start", "stop", "restart", "enable", "disable", "journal"}}},
+		Resources: []map[string]any{{"id": "systemd", "type": "package", "package": "systemd"}}}
+}
+
+func packageManagerHolder() catalogue.Manifest {
+	return catalogue.Manifest{Module: "pacman", Version: "1",
+		Claims:    []catalogue.Claim{{Name: catalogue.PackageManagerSeat, Scope: catalogue.ScopeNode}},
+		Resources: []map[string]any{{"id": "refresh", "type": "service", "unit": "pacman-refresh.timer"}}}
+}
+
+func aDaemon() catalogue.Manifest {
+	return catalogue.Manifest{Module: "sshd", Version: "1",
+		Resources: []map[string]any{{"id": "sshd", "type": "service", "unit": "sshd.service"}}}
+}
+
+func TestAnAssignmentWithoutItsHolderIsRefusedAndNotKept(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, serviceManagerHolder())
+	register(t, open, packageManagerHolder())
+	register(t, open, aDaemon())
+
+	_, err := assign(ctx, open, "laptop", "sshd")
+	if err == nil {
+		t.Fatal("sshd went onto a machine nothing holds the service manager of")
+	}
+	for _, want := range []string{catalogue.ServiceManagerSeat, "systemd", "ADR 0207"} {
+		if !strings.Contains(err.Error(), want) {
+			t.Errorf("the refusal does not say %q:\n%v", want, err)
+		}
+	}
+	assigned, err := open.inventory.Assigned(ctx, "laptop")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if contains(assigned, "sshd") {
+		t.Fatalf("a refused assignment was kept: %v", assigned)
+	}
+
+	// The holders depend on each other, so neither goes on alone — and both go on in one act.
+	if _, err := assign(ctx, open, "laptop", "systemd"); err == nil {
+		t.Fatal("systemd went on alone though its package needs a package manager")
+	}
+	if said, err := assign(ctx, open, "laptop", "systemd", "pacman"); err != nil {
+		t.Fatalf("the two holders assigned together were refused: %v\n%s", err, said)
+	}
+	if said, err := assign(ctx, open, "laptop", "sshd"); err != nil {
+		t.Fatalf("sshd beside its holder was refused: %v\n%s", err, said)
+	}
+}
+
+func TestTheControllerSeatsAssignTakesSeveralModulesAsOneAct(t *testing.T) {
+	argv, err := argvFor("assign", map[string]any{"node": "laptop", "module": "systemd, pacman"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.Join(argv, " ") != "assign laptop systemd pacman" {
+		t.Errorf("the seat's assign became %v", argv)
+	}
+}
+
+func TestUnassigningTheLastHolderUnderItsDependentsIsRefused(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, serviceManagerHolder())
+	register(t, open, packageManagerHolder())
+	register(t, open, aDaemon())
+	if _, err := assign(ctx, open, "laptop", "systemd", "pacman", "sshd"); err != nil {
+		t.Fatal(err)
+	}
+
+	_, err := unassign(ctx, open, "laptop", "systemd")
+	if err == nil {
+		t.Fatal("the service manager came off a machine still running services")
+	}
+	for _, want := range []string{catalogue.ServiceManagerSeat, "sshd", "pacman"} {
+		if !strings.Contains(err.Error(), want) {
+			t.Errorf("the refusal does not name %q:\n%v", want, err)
+		}
+	}
+	assigned, _ := open.inventory.Assigned(ctx, "laptop")
+	if !contains(assigned, "systemd") {
+		t.Fatalf("a refused unassignment took the module off anyway: %v", assigned)
+	}
+	if _, err := unassign(ctx, open, "laptop", "sshd"); err != nil {
+		t.Fatalf("a dependent could not come off: %v", err)
+	}
+}
+
+func TestStatusReportsAnUnheldDependencyWithoutRefusingTheMachine(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, serviceManagerHolder())
+	register(t, open, aDaemon())
+	// Assigned straight into the store: a machine whose modules predate the rule, which is every
+	// machine on the day it ships.
+	if _, err := open.inventory.Assign(ctx, "laptop", "sshd"); err != nil {
+		t.Fatal(err)
+	}
+
+	asked, err := theThreeQuestions(ctx, open)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, refused := asked.refused["laptop"]; refused {
+		t.Fatalf("an unmet dependency refused the machine before the switch: %s", asked.refused["laptop"])
+	}
+	if asked.well() {
+		t.Error("a mesh with an unheld dependency reads as all well")
+	}
+	got := printed(t, func() error { return printStatus(asked) })
+	for _, want := range []string{"unheld", "laptop", "sshd", catalogue.ServiceManagerSeat, "systemd"} {
+		if !strings.Contains(got, want) {
+			t.Errorf("status does not say %q:\n%s", want, got)
+		}
+	}
+	body, err := statusAsJSON(asked)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var doc struct {
+		Unheld []catalogue.Unheld `json:"unheld"`
+	}
+	if err := json.Unmarshal(body, &doc); err != nil {
+		t.Fatal(err)
+	}
+	if len(doc.Unheld) != 1 || doc.Unheld[0].Module != "sshd" || doc.Unheld[0].Seat != catalogue.ServiceManagerSeat {
+		t.Errorf("the document's unheld is %+v", doc.Unheld)
+	}
+}