Review of 083: a message the store cannot take is held and retried on a ticker, not slept on, so enrolments are answered meanwhile; a newer one per subject supersedes; the password is replaced after the spend; the same presenter may finish after a lost answer; upgrades retry only on the store

cmd/mesh-controller/upgrades.go

@@ -28,13 +28,15 @@ type following struct{ open *stores }
 func (f following) Upgraded(ctx context.Context, u link.Upgraded) error {
 	inv := f.open.inventory
 
+	// The store read first, and an outage there said as one, so the announcement is held and asked
+	// again (novox/hq issue 083). Only here: a push that fails further down is not asked again.
 	decision, err := inv.UpgradeOf(ctx, u.Module)
 	if err != nil {
-		return err
+		return notNow(err)
 	}
 	on, err := inv.Running(ctx, u.Module)
 	if err != nil {
-		return err
+		return notNow(err)
 	}
 	if len(on) == 0 {
 		fmt.Printf("%s moved to %s; no machine runs it\n", u.Module, shortCommit(u.Commit))
@@ -194,3 +196,12 @@ func (f following) Announceable(ctx context.Context) ([]link.Announcement, error
 	}
 	return out, nil
 }
+
+// notNow marks a store that could not be read right now, so the announcement is held rather than
+// lost; anything else is returned as it was.
+func notNow(err error) error {
+	if inventory.Unreachable(err) {
+		return fmt.Errorf("%w: %w", link.ErrTryAgain, err)
+	}
+	return err
+}