application_controller.html.erb

<% if current_user %>
  <script>

      var pusher = new Pusher('HIDDEN', { authEndpoint: '/pusher/auth' , cluster: 'HIDDEN',
          auth: {
              headers: {
                  'X-CSRF-Token': "<%= form_authenticity_token %>"
              }
          }
      });

      var channel = pusher.subscribe('presence-HIDDEN-<%= Rails.env %>')
      channel.bind('pusher:subscription_succeeded', function() {
          var me = channel.members.me;
          var userId = me.id.substring(0,me.id.indexOf('-'));
          var userInfo = me.info;
          var sessionCount = 0
          for(var key in channel.members.members) {
              var value = channel.members.members[key]
              var memberId = key.substring(0,key.indexOf('-'))
              if(userId == memberId){
                  sessionCount = sessionCount+1
              }
          if(sessionCount >25)
          {
                  setTimeout(
                      function()
                      {
                          $.ajax({
                              url: '/my/users/sign_out',
                              type: 'DELETE',
                              success: function(result) {
                                  location.reload();
                              }
                          });
                      }, 5000);
          }
          }

      });

      channel.bind('pusher:subscription_error', function(status) {
          console.log(status)
      });



  </script>
<% end  %>

pusher_controller.rb

  def auth
    require 'pusher'

    pusher = Pusher::Client.new(
        app_id: 'HIDDEN',
        key: 'HIDDEN',
        secret: 'HIDDEN',
        cluster: 'us2',
        use_tls: true
    )


    if current_user
      response = pusher.authenticate(params[:channel_name], params[:socket_id], {
          user_id: current_user.id.to_s + '-' +  DateTime.now.strftime('%s'), # => required
          user_info: { # => optional - for example
                       name: current_user.name,
                       email: current_user.email + '-' +  DateTime.now.strftime('%s')
          }
      })
      render json: response
    else
      render text: 'Forbidden', status: '403'
    end
  end
end