Asp.NET Core 限流控制-AspNetCoreRateLimit
起因：
近期項(xiàng)目中，提供了一些調(diào)用頻率較高的api接口，需要保障服務(wù)器的穩(wěn)定運(yùn)行；需要對(duì)提供的接口進(jìn)行限流控制。避免因客戶端頻繁的請(qǐng)求導(dǎo)致服務(wù)器的壓力。
一、AspNetCoreRateLimit 介紹
AspNetCoreRateLimit是一個(gè)ASP.NET Core速率限制的解決方案，旨在控制客戶端根據(jù)IP地址或客戶端ID向Web API或MVC應(yīng)用發(fā)出的請(qǐng)求的速率。AspNetCoreRateLimit包含一個(gè)IpRateLimitMiddleware和ClientRateLimitMiddleware，每個(gè)中間件可以根據(jù)不同的場(chǎng)景配置限制允許IP或客戶端，自定義這些限制策略，也可以將限制策略應(yīng)用在每個(gè)API URL或具體的HTTP Method上。
二、AspNetCoreRateLimit使用
由上面介紹可知AspNetCoreRateLimit支持了兩種方式：基于客戶端IP（IpRateLimitMiddleware）和客戶端ID（ClientRateLimitMiddleware）速率限制 接下來就分別說明使用方式
添加Nuget包引用：
Install-Package AspNetCoreRateLimit
基于客戶端IP速率限制
1、修改Startup.cs中方法：
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
//需要從加載配置文件appsettings.json
services.AddOptions();
//需要存儲(chǔ)速率限制計(jì)算器和ip規(guī)則
services.AddMemoryCache();
//從appsettings.json中加載常規(guī)配置，IpRateLimiting與配置文件中節(jié)點(diǎn)對(duì)應(yīng)
services.Configure<IpRateLimitOptions>(Configuration.GetSection("IpRateLimiting"));
//從appsettings.json中加載Ip規(guī)則
services.Configure<IpRateLimitPolicies>(Configuration.GetSection("IpRateLimitPolicies"));
//注入計(jì)數(shù)器和規(guī)則存儲(chǔ)
services.AddSingleton<IIpPolicyStore, MemoryCacheIpPolicyStore>();
services.AddSingleton<IRateLimitCounterStore, MemoryCacheRateLimitCounterStore>();
services.AddControllers();
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
//配置（解析器、計(jì)數(shù)器密鑰生成器）
services.AddSingleton<IRateLimitConfiguration, RateLimitConfiguration>();
//Other Code
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
//Other Code
app.UseRouting();
app.UseAuthorization();
//啟用客戶端IP限制速率
app.UseIpRateLimiting();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
}
2、在appsettings.json中添加通用配置項(xiàng)節(jié)點(diǎn)：（IpRateLimiting節(jié)點(diǎn)與Startup中取的節(jié)點(diǎn)對(duì)應(yīng)）
"IpRateLimiting": {
//false，則全局將應(yīng)用限制，并且僅應(yīng)用具有作為端點(diǎn)的規(guī)則*。例如，如果您設(shè)置每秒5次調(diào)用的限制，則對(duì)任何端點(diǎn)的任何HTTP調(diào)用都將計(jì)入該限制
//true， 則限制將應(yīng)用于每個(gè)端點(diǎn)，如{HTTP_Verb}{PATH}。例如，如果您為*:/api/values客戶端設(shè)置每秒5個(gè)呼叫的限制，
"EnableEndpointRateLimiting": false,
//false，拒絕的API調(diào)用不會(huì)添加到調(diào)用次數(shù)計(jì)數(shù)器上;如 客戶端每秒發(fā)出3個(gè)請(qǐng)求并且您設(shè)置了每秒一個(gè)調(diào)用的限制，則每分鐘或每天計(jì)數(shù)器等其他限制將僅記錄第一個(gè)調(diào)用，即成功的API調(diào)用。如果您希望被拒絕的API調(diào)用計(jì)入其他時(shí)間的顯示（分鐘，小時(shí)等）
//，則必須設(shè)置StackBlockedRequests為true。
"StackBlockedRequests": false,
//Kestrel 服務(wù)器背后是一個(gè)反向代理，如果你的代理服務(wù)器使用不同的頁眉然后提取客戶端IP X-Real-IP使用此選項(xiàng)來設(shè)置
"RealIpHeader": "X-Real-IP",
//取白名單的客戶端ID。如果此標(biāo)頭中存在客戶端ID并且與ClientWhitelist中指定的值匹配，則不應(yīng)用速率限制。
"ClientIdHeader": "X-ClientId",
//限制狀態(tài)碼
"HttpStatusCode": 429,
////IP白名單:支持Ip v4和v6
//"IpWhitelist": [ "127.0.0.1", "::1/10", "192.168.0.0/24" ],
////端點(diǎn)白名單
//"EndpointWhitelist": [ "get:/api/license", "*:/api/status" ],
////客戶端白名單
//"ClientWhitelist": [ "dev-id-1", "dev-id-2" ],
//通用規(guī)則
"GeneralRules": [
{
//端點(diǎn)路徑
"Endpoint": "*",
//時(shí)間段，格式：{數(shù)字}{單位}；可使用單位：s, m, h, d
"Period": "1s",
//限制
"Limit": 2
},
//15分鐘只能調(diào)用100次
{"Endpoint": "*","Period": "15m","Limit": 100},
//12H只能調(diào)用1000
{"Endpoint": "*","Period": "12h","Limit": 1000},
//7天只能調(diào)用10000次
{"Endpoint": "*","Period": "7d","Limit": 10000}
]
}
配置節(jié)點(diǎn)已添加相應(yīng)注釋信息。
規(guī)則設(shè)置格式：
端點(diǎn)格式：{HTTP_Verb}:{PATH}，您可以使用asterix符號(hào)來定位任何HTTP謂詞。
期間格式：{INT}{PERIOD_TYPE}，您可以使用以下期間類型之一：s, m, h, d。
限制格式：{LONG}
3、特點(diǎn)Ip限制規(guī)則設(shè)置，在appsettings.json中添加 IP規(guī)則配置節(jié)點(diǎn)
"IpRateLimitPolicies": {
//ip規(guī)則
"IpRules": [
{
//IP
"Ip": "84.247.85.224",
//規(guī)則內(nèi)容
"Rules": [
//1s請(qǐng)求10次
{"Endpoint": "*","Period": "1s","Limit": 10},
//15分鐘請(qǐng)求200次
{"Endpoint": "*","Period": "15m","Limit": 200}
]
},
{
//ip支持設(shè)置多個(gè)
"Ip": "192.168.3.22/25",
"Rules": [
//1秒請(qǐng)求5次
{"Endpoint": "*","Period": "1s","Limit": 5},
//15分鐘請(qǐng)求150次
{"Endpoint": "*","Period": "15m","Limit": 150},
//12小時(shí)請(qǐng)求500次
{"Endpoint": "*","Period": "12h","Limit": 500}
]
}
]
}
基于客戶端ID速率限制
1、修改Startup文件：
public void ConfigureServices(IServiceCollection services)
{
//需要從加載配置文件appsettings.json
services.AddOptions();
//需要存儲(chǔ)速率限制計(jì)算器和ip規(guī)則
services.AddMemoryCache();
//從appsettings.json中加載常規(guī)配置
services.Configure<ClientRateLimitOptions>(Configuration.GetSection("IPRateLimiting"));
//從appsettings.json中加載客戶端規(guī)則
services.Configure<ClientRateLimitPolicies>(Configuration.GetSection("ClientRateLimitPolicies"));
//注入計(jì)數(shù)器和規(guī)則存儲(chǔ)
services.AddSingleton<IClientPolicyStore, MemoryCacheClientPolicyStore>();
services.AddSingleton<IRateLimitCounterStore, MemoryCacheRateLimitCounterStore>();
services.AddControllers();
// https://github.com/aspnet/Hosting/issues/793
// the IHttpContextAccessor service is not registered by default.
//注入計(jì)數(shù)器和規(guī)則存儲(chǔ)
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
//配置（解析器、計(jì)數(shù)器密鑰生成器）
services.AddSingleton<IRateLimitConfiguration, RateLimitConfiguration>();
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
//啟用客戶端限制
app.UseClientRateLimiting();
app.UseMvc();
}
2、通用配置采用IP限制相同配置，添加客戶端限制配置：
//客戶端限制設(shè)置
"ClientRateLimitPolicies": {
"ClientRules": [
{
//客戶端id
"ClientId": "client-id-1",
"Rules": [
{"Endpoint": "*","Period": "1s","Limit": 10},
{"Endpoint": "*","Period": "15m","Limit": 200}
]
},
{
"ClientId": "client-id-2",
"Rules": [
{"Endpoint": "*","Period": "1s","Limit": 5},
{"Endpoint": "*","Period": "15m","Limit": 150},
{"Endpoint": "*","Period": "12h","Limit": 500}
]
}
]
}
3、調(diào)用結(jié)果：
設(shè)置規(guī)則：1s只能調(diào)用一次：首次調(diào)用
調(diào)用第二次：自定義返回內(nèi)容
三、其他
運(yùn)行時(shí)更新速率限制
添加IpRateLimitController控制器：
/// <summary>
/// IP限制控制器
/// </summary>
[Route("api/[controller]")]
[ApiController]
public class IpRateLimitController : ControllerBase
{
private readonly IpRateLimitOptions _options;
private readonly IIpPolicyStore _ipPolicyStore;
/// <summary>
///
/// </summary>
/// <param name="optionsAccessor"></param>
/// <param name="ipPolicyStore"></param>
public IpRateLimitController(IOptions<IpRateLimitOptions> optionsAccessor, IIpPolicyStore ipPolicyStore)
{
_options = optionsAccessor.Value;
_ipPolicyStore = ipPolicyStore;
}
/// <summary>
/// 獲取限制規(guī)則
/// </summary>
/// <returns></returns>
[HttpGet]
public async Task<IpRateLimitPolicies> Get()
{
return await _ipPolicyStore.GetAsync(_options.IpPolicyPrefix);
}
/// <summary>
///
/// </summary>
[HttpPost]
public async Task Post(IpRateLimitPolicy ipRate)
{
var pol = await _ipPolicyStore.GetAsync(_options.IpPolicyPrefix);
if (ipRate != null)
{
pol.IpRules.Add(ipRate);
await _ipPolicyStore.SetAsync(_options.IpPolicyPrefix, pol);
}
}
}
分布式部署時(shí)，需要將速率限制計(jì)算器和ip規(guī)則存儲(chǔ)到分布式緩存中如Redis
修改注入對(duì)象
// inject counter and rules distributed cache stores
services.AddSingleton<IClientPolicyStore, DistributedCacheClientPolicyStore>();
services.AddSingleton<IRateLimitCounterStore,DistributedCacheRateLimitCounterStore>();
添加Nuget包 Microsoft.Extensions.Caching.StackExchangeRedis
在Startup中設(shè)置Redis連接
services.AddStackExchangeRedisCache(options =>
{
options.ConfigurationOptions = new ConfigurationOptions
{
//silently retry in the background if the Redis connection is temporarily down
AbortOnConnectFail = false
};
options.Configuration = "localhost:6379";
options.InstanceName = "AspNetRateLimit";
});
限制時(shí)自定義相應(yīng)結(jié)果：
//請(qǐng)求返回
"QuotaExceededResponse": {
"Content": "{{\"code\":429,\"msg\":\"Visit too frequently, please try again later\",\"data\":null}}",
"ContentType": "application/json;utf-8",
"StatusCode": 429
},
調(diào)用時(shí)返回結(jié)果：
其他：
示例代碼：https://github.com/cwsheng/WebAPIVersionDemo
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