在dotent core 2.0 實作相依服務健康狀態監視－FIVE

參考文件:

https://scottsauber.com/2017/05/22/using-the-microsoft-aspnetcore-healthchecks-package/

https://docs.microsoft.com/zh-tw/dotnet/standard/microservices-architecture/implement-resilient-applications/monitor-app-health

1.新增套件(未來在dotent core 2.2會直接有)

dotnet add package Microsoft.AspNetCore.HealthChecks --version 1.0.0

ref: https://www.nuget.org/packages/Microsoft.AspNetCore.HealthChecks/

2.為每個微服務呼叫一個 AddUrlCheck 方法

位置: Startup.cs > ConfigureServices

假設有一個相依的微服務網址為http://localhost:805

services.AddHealthChecks(checks =>{
checks.AddUrlCheck("http://localhost:805");
});

3.讓服務或 Web 應用程式公開健康狀態檢查端點

啟用 UseHealthChecks([url_for_health_checks]) 擴充方法。

位置:Program.cs

WebHost.CreateDefaultBuilder(args)
.UseStartup<Startup>()
.UseHealthChecks("/hc") //啟用 UseHealthChecks擴充方法。 
.Build();

4.測試情況

http://localhost:56432/hc (假設啟用服務為localhost:56432)

健康

{"status":"Healthy"}

不健康

{"status":"Unhealthy"}

其它1.自訂檢查

自訂redis的連線檢查可以參考下面範例

ref:https://dejanstojanovic.net/aspnet/2018/may/redis-health-check-in-aspnet-core-webapi/

services.AddHealthChecks(checks =>{
checks
.AddRedisCheck() //redis檢查
.AddMongoCheck() //mongo檢查
.AddUrlCheck("http://localhost:805") //apiproxy服務檢查
;
});

其它2.顯示詳細錯誤

因為預設對外端口只會顯示Healthy或Unhealthy兩種資訊，如果需要觀察詳細錯誤訊息可以參考下面範例

讀取checkResult的資料可顯示詳細訊息

{
    "CheckStatus": 2,
    "Description": "RedisCheck: RedisCheck: Healthy\r\nMongoCheck: MongoCheck: Healthy\r\nUrlCheck(http://localhost:805): status code OK (200)",
    "Data": {
      "RedisCheck": {},
      "MongoCheck": {},
      "UrlCheck(http://localhost:805)": {
        "url": "http://localhost:805/",
        "status": 200,
        "reason": "OK",
        "body": "OK"
      }
    },
    "Results": {
      "RedisCheck": {
        "CheckStatus": 2,
        "Data": {},
        "Description": "RedisCheck: Healthy"
      },
      "MongoCheck": {
        "CheckStatus": 2,
        "Data": {},
        "Description": "MongoCheck: Healthy"
      },
      "UrlCheck(http://localhost:805)": {
        "CheckStatus": 2,
        "Data": {
          "url": "http://localhost:805/",
          "status": 200,
          "reason": "OK",
          "body": ""
        },
        "Description": "status code OK (200)"
      }
    }
  }