.NET Cookbook

Persist session to Redis

[!TIP] Before continuing, please refer to recipe named Core like Startup under ASP.NET

This recipe guides you on, how to make use of redis, for session persistence in classic ASP.NET applications, using Steeltoe connectors.

Prerequisites

• Install Redis version 2.6 or higher to support session
• Visual studio 15.3 or more

Steps to add session/caching to classic ASP.NET application (Common steps)

• Follow the instructions from the recipe Core like Startup This will add the support for .NET Core like DI, Configuration injection, use of Steeltoe Core extension methods, etc.

• Add nuget package reference to Steeltoe.Extensions.Configuration.CloudFoundryCore

• Add the IConfigurationBuilder extensions methods (as below) to pull in configurations from environment variables and VCAP_SERVICES (user provided). Optional to add JSON files, YAML files, etc as needed.

      public class BootConfig
      {
          ...
          public static void Configure(string environment)
          {
              ...
              .ConfigureAppConfiguration((builderContext, configBuilder) =>
              {
                  configBuilder.AddCloudFoundry();
                  configBuilder.AddEnvironmentVariables();
              })
              ...
          }
          ...
      }
  

• Add nuget package reference to Steeltoe.CloudFoundry.ConnectorCore

• Add the Steeltoe’s IServiceCollection extension method (as below) which injects an implementation of IConnectionMultiplexer. Steeltoe is smart to pull the configurations from VCAP_SERVICES, if app is bounded to a redis instance, else use the default host and port for Redis

      public class BootConfig
      {
          ...
          public static void Configure(string environment)
          {
              ...
              .ConfigureServices((builderContext, services) =>
              {
                  services.AddRedisConnectionMultiplexer(builderContext.Configuration);
              })
              ...
          }
          ...
      }
  

• Create a class called RedisConfig as below, which serves the connection string to RedisSessionStateProvider mentioned in the web.config (later in the steps)

      public class RedisConfig
      {
          static IConnectionMultiplexer connectionMultiplexer;
          static RedisConfig()
          {
              connectionMultiplexer = BootConfig.GetService<IConnectionMultiplexer>() 
                  ?? throw new ArgumentNullException(nameof(IConnectionMultiplexer));
          }
  
          public static string GetConnectionString()
          {
              return connectionMultiplexer.Configuration;
          }
      }
  

• Add reference to the nuget package Microsoft.Web.RedisSessionStateProvider. This modifies the web.config file adding custom session state provider and machine key sections under system.web section

• Overwrite the sessionState section as below, where we mentioned the class and method which serves the connection string. Note that the class name should be fully qualified

     <sessionState mode="Custom" customProvider="RedisSessionStateStore">
        <providers>
          <add name="RedisSessionStateStore" type="Microsoft.Web.Redis.RedisSessionStateProvider"
               settingsClassName="RedisConfig"
               settingsMethodName="GetConnectionString" />
        </providers>
      </sessionState>
  

• Use a generator like this one to create and update the machineKey section

• Application is all set to use Redis as its backing store for session.

For more details and sample application, you can refer to this article

Hope you have fun!