Function startRefuseThenServe

pkg/util_simulate_refuse_integration_test.go:19–44

startRefuseThenServe reserves a free port, releases it so connects are REFUSED for `refuse`, then re-binds it and serves GET /ping -> 200 {"msg":"pong"}. This reproduces an app container that briefly refuses connections while it is still coming up (the CI contention scenario the retry exists for).

(t *testing.T, refuse time.Duration)

// This reproduces an app container that briefly refuses connections while it is
// still coming up (the CI contention scenario the retry exists for).
func startRefuseThenServe(t *testing.T, refuse time.Duration) (baseURL string, stop func()) {
	t.Helper()
	l, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("reserve port: %v", err)
	}
	addr := l.Addr().String()
	_ = l.Close() // the port now actively refuses until we re-bind below

	mux := http.NewServeMux()
	mux.HandleFunc("/ping", func(w http.ResponseWriter, _ *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write([]byte(`{"msg":"pong"}`))
	})
	srv := &http.Server{Handler: mux}
	go func() {
		time.Sleep(refuse) // connects to addr are refused during this window
		ln, lerr := net.Listen("tcp", addr)
		if lerr != nil {
			return
		}
		_ = srv.Serve(ln)
	}()
	return "http://" + addr, func() { _ = srv.Close() }
}

func pingTestCase(baseURL string) *models.TestCase {
	return &models.TestCase{