redis-blog-post-1.cs

public class Startup
{
    public Startup(IConfiguration configuration) => Configuration = configuration;

    public IConfiguration Configuration { get; }

    public void ConfigureServices(IServiceCollection services)
    {
        IConfigurationSection apiSettingsSection = Configuration.GetSection(Constants.ConfigurationKeys.ApiSettingsKeyName);
        services.Configure<ApiSettings>(apiSettingsSection);

        DistributedCacheMethodOption distributedCacheMethod = apiSettingsSection.GetValue<DistributedCacheMethodOption>(nameof(ApiSettings.DistributedCacheMethod));

        services.AddDistributedCache(Configuration, distributedCacheMethod);
    }
}

public static class ServiceCollectionExtension
{
    public static IServiceCollection AddDistributedCache(this IServiceCollection services, IConfiguration configuration, DistributedCacheMethodOption distributedCacheMethodOption)
    {
        switch (distributedCacheMethodOption)
        {
            case DistributedCacheMethodOption.InMemory:
                services.AddDistributedMemoryCache();
                break;
            case DistributedCacheMethodOption.Redis:
                services.AddStackExchangeRedisCache(options => {
                    options.Configuration = configuration[Constants.ConfigurationKeys.RedisConnectionStringKeyName];
                    options.InstanceName = Constants.DistributedCache.InstanceName;
                });
                break;
            default:
                throw new ArgumentOutOfRangeException(nameof(distributedCacheMethodOption));
        }

        return services;
    }
}