ASP.NET Core 6如何为AddAccessTokenManagement配置Redis缓存？

该方案完全可行，IdentityModel.AspNetCore框架支持自定义令牌缓存存储，通过替换默认内存缓存为Redis，可实现多App Service实例共享令牌，避免各实例重复向授权服务器请求令牌的问题。

具体实现步骤 #

1. 安装必要NuGet包 #

Install-Package StackExchange.Redis
Install-Package IdentityModel.AspNetCore
Install-Package Microsoft.Extensions.Caching.StackExchangeRedis

2. 配置Redis缓存服务 #

在Program.cs中添加Redis分布式缓存配置：

builder.Services.AddStackExchangeRedisCache(options =>
{
    options.Configuration = builder.Configuration.GetConnectionString("Redis");
    options.InstanceName = "TokenCache:";
});

3. 实现Redis令牌缓存 #

自定义实现IClientTokenCache接口，基于Redis存储令牌：

public class RedisClientTokenCache : IClientTokenCache
{
    private readonly IDistributedCache _distributedCache;
    private readonly ILogger<RedisClientTokenCache> _logger;

    public RedisClientTokenCache(IDistributedCache distributedCache, ILogger<RedisClientTokenCache> logger)
    {
        _distributedCache = distributedCache;
        _logger = logger;
    }

    public async Task<ClientToken> GetAsync(string clientName, CancellationToken cancellationToken = default)
    {
        var cacheKey = $"ClientToken:{clientName}";
        var tokenJson = await _distributedCache.GetStringAsync(cacheKey, cancellationToken);
        return string.IsNullOrEmpty(tokenJson) ? null : JsonSerializer.Deserialize<ClientToken>(tokenJson);
    }

    public async Task SetAsync(string clientName, ClientToken token, CancellationToken cancellationToken = default)
    {
        if (token == null) return;
        
        var cacheKey = $"ClientToken:{clientName}";
        var tokenJson = JsonSerializer.Serialize(token);
        // 提前1分钟过期，避免使用已失效的令牌
        var expiration = token.Expiration.Subtract(DateTime.UtcNow).AddMinutes(-1);
        
        await _distributedCache.SetStringAsync(
            cacheKey, 
            tokenJson, 
            new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow = expiration }, 
            cancellationToken);
    }

    public async Task RemoveAsync(string clientName, CancellationToken cancellationToken = default)
    {
        var cacheKey = $"ClientToken:{clientName}";
        await _distributedCache.RemoveAsync(cacheKey, cancellationToken);
    }
}

4. 替换默认令牌缓存 #

修改原有服务注册代码，将默认内存缓存替换为自定义Redis缓存：

foreach (var tokenEndpointConfiguration in tokenEndpointConfigurations)
{
    services.AddAccessTokenManagement(options =>
    {
        options.Client.Clients.Add(tokenEndpointConfiguration.Name, new ClientCredentialsTokenRequest()
        {
            Address = tokenEndpointConfiguration.TokenUrl,
            ClientId = tokenEndpointConfiguration.ClientId,
            ClientSecret = tokenEndpointConfiguration.ClientSecret
        });
    })
    .AddClientAccessTokenCache<RedisClientTokenCache>(); // 替换缓存实现

    services.AddHttpClient(tokenEndpointConfiguration.Name, c =>
    {
        c.BaseAddress = new Uri(tokenEndpointConfiguration.BaseUrl);
    })
    .AddClientAccessTokenHandler(tokenClientName: tokenEndpointConfiguration.Name);
}

services.AddSingleton<HttpClientSelectorService>();
services.AddSingleton<IClientTokenCache, RedisClientTokenCache>();

注意事项 #

• 确保所有App Service实例能访问同一Redis集群/实例，配置正确的连接字符串。
• 令牌缓存过期时间需预留缓冲（如提前1分钟），避免因网络延迟等问题使用已失效令牌。
• 建议配置Redis的高可用方案（如哨兵、集群），避免单点故障影响令牌获取。

内容的提问来源于stack exchange，提问作者erionpc