Function startBuiltinPostgres

cli/server.go:2354–2447

(ctx context.Context, cfg config.Root, logger slog.Logger, customCacheDir string)

}

func startBuiltinPostgres(ctx context.Context, cfg config.Root, logger slog.Logger, customCacheDir string) (string, func() error, error) {
	usr, err := user.Current()
	if err != nil {
		return "", nil, err
	}
	if usr.Uid == "0" {
		return "", nil, xerrors.New("The built-in PostgreSQL cannot run as the root user. Create a non-root user and run again!")
	}

	cachePath := filepath.Join(cfg.PostgresPath(), "cache")
	if customCacheDir != "" {
		cachePath = filepath.Join(customCacheDir, "postgres")
	}
	stdlibLogger := slog.Stdlib(ctx, logger.Named("postgres"), slog.LevelDebug)

	// If the port is not defined, an available port will be found dynamically. This has
	// implications in CI because here is no way to tell Postgres to use an ephemeral
	// port, so to avoid flaky tests in CI we need to retry EmbeddedPostgres.Start in
	// case of a race condition where the port we quickly listen on and close in
	// embeddedPostgresURL() is not free by the time the embedded postgres starts up.
	// The maximum retry attempts _should_ cover most cases where port conflicts occur
	// in CI and cause flaky tests.
	maxAttempts := 1
	_, err = cfg.PostgresPort().Read()
	// Important: if retryPortDiscovery is changed to not include testing.Testing(),
	// the retry logic below also needs to be updated to ensure we don't delete an
	// existing database
	retryPortDiscovery := errors.Is(err, os.ErrNotExist) && testing.Testing()
	if retryPortDiscovery {
		maxAttempts = 10
	}

	var startErr error
	for attempt := 0; attempt < maxAttempts; attempt++ {
		if retryPortDiscovery && attempt > 0 {
			// Clean up the data and runtime directories and the port file from the
			// previous failed attempt to ensure a clean slate for the next attempt.
			_ = os.RemoveAll(filepath.Join(cfg.PostgresPath(), "data"))
			_ = os.RemoveAll(filepath.Join(cfg.PostgresPath(), "runtime"))
			_ = cfg.PostgresPort().Delete()
		}

		// Ensure a password and port have been generated.
		connectionURL, err := embeddedPostgresURL(cfg)
		if err != nil {
			return "", nil, err
		}
		pgPassword, err := cfg.PostgresPassword().Read()
		if err != nil {
			return "", nil, xerrors.Errorf("read postgres password: %w", err)
		}
		pgPortRaw, err := cfg.PostgresPort().Read()
		if err != nil {
			return "", nil, xerrors.Errorf("read postgres port: %w", err)
		}
		pgPort, err := strconv.ParseUint(pgPortRaw, 10, 16)
		if err != nil {
			return "", nil, xerrors.Errorf("parse postgres port: %w", err)