func New()

in proxy/lib/proxy/proxy.go [114:160]
39 lines of code
7 McCabe index (conditional complexity)

func New(ctx context.Context, r *mux.Router, opts *Options, logger *logging.Client, iamClient IAMClient, secretManagerClient SecretManagerClient, cacheClient func() cache.Client) (*Service, error) {
	u, err := url.Parse(opts.ProxyTo)
	if err != nil {
		return nil, fmt.Errorf("url.Parse(%s): %v", opts.ProxyTo, err)
	}

	s := &Service{
		opts:                        opts,
		fhirProxy:                   httputil.NewSingleHostReverseProxy(u),
		iamClient:                   iamClient,
		secretManagerClient:         secretManagerClient,
		gcpAccessLastRequestStarted: time.Now(),
	}

	issSec, err := s.fetchFhirIssuerClientSecret(ctx)
	if err != nil {
		return nil, err
	}
	if len(issSec) > 0 {
		s.opts.FhirIssuerClientSecret = issSec
	}

	clients, err := s.fetchClientsOfProxySecret(ctx)
	if err != nil {
		return nil, err
	}
	if len(clients) > 0 {
		s.opts.ClientsOfProxy = clients
	}

	tok, expire, err := s.fetchAccessTokenForSA(ctx)
	if err != nil {
		return nil, fmt.Errorf("request access token for service account failed: %v", err)
	}
	// Lock is not needed at service bootstrap.
	s.lockedUpdateToken(tok, expire)

	proxyDirector(s.fhirProxy)
	responseHeaderFilter(s.fhirProxy)
	s.fhirProxy.Transport = Transport

	checker := auth.NewChecker(logger, opts.FhirIssuer, nil, nil, nil, opts.UseUserinfoToVerifyAccessToken, cacheClient)
	r.PathPrefix("/.well-known/smart-configuration").HandlerFunc(auth.MustWithAuth(s.wellKnownSmartConfigure, checker, auth.RequireNone))
	r.PathPrefix("/").HandlerFunc(auth.MustWithAuth(s.proxy, checker, auth.Require{Role: auth.User, SelfClientID: opts.Audience}))

	return s, nil
}