Keep a refused registration left to the build records, in the store and the process, so the look fails the plan rather than settling it built; and forget a deleted module and say what was never sent when the records settle (issue 1708)

internal/inventory/migrations/0107-a-refused-registration-is-kept.sql

@@ -0,0 +1,10 @@
+-- A build's outcome whose registration the mesh refused, by the build's id (novox/hq issue 1708). The build record says
+-- what the builder said, which worked; an outcome the event loop could not take into the plans (another act held them)
+-- is settled from the records by the look, and without this it would read the refused build as built. Kept in the
+-- store so a controller replaced before the settle still fails the plan.
+create table build_refused (
+    id     text primary key,
+    module text not null,
+    why    text not null,
+    at     timestamptz not null default now()
+);

internal/inventory/refused.go

@@ -0,0 +1,33 @@
+package inventory
+
+import "context"
+
+// RecordRefused keeps that the mesh refused to register a build's outcome, and why (novox/hq issue 1708): the build
+// record says the builder's words, which worked, and the look that settles a plan from the records reads this to fail
+// it instead. The first refusal of an id stands.
+func (i *Inventory) RecordRefused(ctx context.Context, id, module, why string) error {
+	_, err := i.store.Pool().Exec(ctx,
+		`insert into build_refused (id, module, why) values ($1, $2, $3) on conflict (id) do nothing`, id, module, why)
+	return err
+}
+
+// RefusedOf is why each of these builds' registration was refused, by id; a build not refused is absent.
+func (i *Inventory) RefusedOf(ctx context.Context, ids []string) (map[string]string, error) {
+	out := map[string]string{}
+	if len(ids) == 0 {
+		return out, nil
+	}
+	rows, err := i.store.Pool().Query(ctx, `select id, why from build_refused where id = any($1)`, ids)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	for rows.Next() {
+		var id, why string
+		if err := rows.Scan(&id, &why); err != nil {
+			return nil, err
+		}
+		out[id] = why
+	}
+	return out, rows.Err()
+}

internal/inventory/refused_test.go

@@ -0,0 +1,28 @@
+//go:build integration
+
+package inventory
+
+import "testing"
+
+// novox/hq issue 1708 (1708/AC6): a refused registration is kept by its build's id, the first refusal standing, and
+// read back for the builds asked about only.
+func TestARefusedRegistrationIsKeptByItsBuild(t *testing.T) {
+	inv := ForTest(t)
+	ctx := t.Context()
+	if err := inv.RecordRefused(ctx, "build-1708-a", "nodered", "a port is taken"); err != nil {
+		t.Fatal(err)
+	}
+	if err := inv.RecordRefused(ctx, "build-1708-a", "nodered", "said again"); err != nil {
+		t.Fatalf("a refusal said twice was refused: %v", err)
+	}
+	got, err := inv.RefusedOf(ctx, []string{"build-1708-a", "build-1708-b"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(got) != 1 || got["build-1708-a"] != "a port is taken" {
+		t.Fatalf("the refusals read back are %v", got)
+	}
+	if none, err := inv.RefusedOf(ctx, nil); err != nil || len(none) != 0 {
+		t.Fatalf("no builds asked about answered %v %v", none, err)
+	}
+}