cmd/mesh-controller/rollout_first_test.go

@@ -82,3 +82,22 @@ func TestAPlanSendsOneMachineFirstAndTheRestAfterItsReport(t *testing.T) {
 		t.Fatalf("a module on one machine waited for more: %+v", step)
 	}
 }
+
+// An announced move of a module an open plan is still rolling out is left to the plan: sending it
+// here as well put the bundle on every machine at once (novox/hq issue 249).
+func TestAnAnnouncedMoveIsLeftToThePlanRollingItOut(t *testing.T) {
+	sent := time.Now()
+	plans := []inventory.Plan{
+		{ID: "plan-done", State: inventory.PlanDone, Modules: map[string]*inventory.PlanModule{"agent": {}}},
+		{ID: "plan-1", State: inventory.PlanRolling, Modules: map[string]*inventory.PlanModule{
+			"agent": {State: "built", First: []string{"ace"}, FirstAt: &sent}, "gitea": {State: "built", SentAt: &sent}}},
+	}
+	if got := rolledOutByAPlan(plans, "agent"); got != "plan-1" {
+		t.Fatalf("a module the plan is rolling out was not left to it: %q", got)
+	}
+	for _, m := range []string{"gitea", "keycloak"} {
+		if got := rolledOutByAPlan(plans, m); got != "" {
+			t.Errorf("%s, which no plan will send, was left to %s", m, got)
+		}
+	}
+}

cmd/mesh-controller/upgrades.go

@@ -56,6 +56,18 @@ func (f following) Upgraded(ctx context.Context, u link.Upgraded) error {
 		return nil
 	}
 
+	// **A plan that holds the module rolls it out, and this does not** (novox/hq issue 249, ADR
+	// 0218). A merge's plan builds the module and sends it one machine first, the rest once that one
+	// has applied it; this announcement arrives as the build registers, and sending here too — one
+	// machine after another without waiting for any to apply — put the new bundle on every machine in
+	// the same minute, whatever the plan was waiting for. A move no plan answers (a build asked by
+	// hand) is still this handler's.
+	if plans, err := inv.OpenPlans(ctx); err != nil {
+		return notNow(err)
+	} else if id := rolledOutByAPlan(plans, u.Module); id != "" {
+		fmt.Printf("%s moved to %s; %s rolls it out to %s\n", u.Module, shortCommit(u.Commit), id, readableList(on))
+		return nil
+	}
 	if decision.Together {
 		fmt.Printf("%s moved to %s; sending %s together\n",
 			u.Module, shortCommit(u.Commit), readableList(on))
@@ -77,6 +89,17 @@ func (f following) Upgraded(ctx context.Context, u link.Upgraded) error {
 	return nil
 }
 
+// rolledOutByAPlan is the open plan that will send a module's machines its new build — one holding
+// the module that has not finished sending it — or empty when none will (novox/hq issue 249).
+func rolledOutByAPlan(plans []inventory.Plan, module string) string {
+	for _, p := range plans {
+		if s, holds := p.Modules[module]; p.Open() && holds && (s == nil || s.SentAt == nil) {
+			return p.ID
+		}
+	}
+	return ""
+}
+
 // readableList names machines the way a sentence does, because this is read by a person deciding
 // whether an upgrade went where they expected.
 func readableList(names []string) string {