func StartTokenServer()

in pkg/sidecar_mounter/sidecar_mounter.go [351:402]
43 lines of code
6 McCabe index (conditional complexity)

func StartTokenServer(ctx context.Context, tokenURLSocketPath string, identityProvider string) {
	// Create a unix domain socket and listen for incoming connections.
	tokenSocketListener, err := net.Listen("unix", tokenURLSocketPath)
	if err != nil {
		klog.Errorf("failed to create socket %q: %v", tokenURLSocketPath, err)

		return
	}
	klog.Infof("created a listener using the socket path %s", tokenURLSocketPath)
	mux := http.NewServeMux()
	mux.HandleFunc("/", func(w http.ResponseWriter, _ *http.Request) {
		ctx, cancel := context.WithCancel(ctx)
		defer cancel()

		k8stoken, err := getK8sTokenFromFile(webhook.SidecarContainerSATokenVolumeMountPath + "/" + webhook.K8STokenPath)
		var stsToken *oauth2.Token
		if err != nil {
			klog.Errorf("failed to get k8s token from path %v", err)
			w.WriteHeader(http.StatusInternalServerError)

			return
		}
		stsToken, err = fetchIdentityBindingToken(ctx, k8stoken, identityProvider)
		if err != nil {
			klog.Errorf("failed to get sts token from path %v", err)
			w.WriteHeader(http.StatusInternalServerError)

			return
		}
		// Marshal the oauth2.Token object to JSON
		jsonToken, err := json.Marshal(stsToken)
		if err != nil {
			klog.Errorf("failed to marshal token to JSON: %v", err)
			w.WriteHeader(http.StatusInternalServerError)

			return
		}
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusOK)
		fmt.Fprint(w, string(jsonToken))
	})

	server := http.Server{
		Handler:      mux,
		ReadTimeout:  10 * time.Second,
		WriteTimeout: 10 * time.Second,
	}

	if err := server.Serve(tokenSocketListener); !errors.Is(err, http.ErrServerClosed) {
		klog.Errorf("Server for %q returns unexpected error: %v", tokenURLSocketPath, err)
	}
}