WebSocket 握手期间出错：意外的响应代码：在 azure 上与 ocelot 网关连接时出现 502答案

【问题标题】：Error during WebSocket handshake: Unexpected response code: 502 when connecting on azure with ocelot gatewayWebSocket 握手期间出错：意外的响应代码：在 azure 上与 ocelot 网关连接时出现 502
【发布时间】：2021-03-01 21:31:18
【问题描述】：

我在我的应用程序中使用 signalR，在 Azure 门户上上传 ocelot 网关时出错

我的ts代码

this.hubConnection = new signalR.HubConnectionBuilder()
        .withUrl("https://url.azurewebsites.net/gatewayOcelot/notification", {
            skipNegotiation: true,
            transport: signalR.HttpTransportType.WebSockets
        })
        .build();

而豹猫路线是

{
  "UpstreamPathTemplate": "/gatewayOcelot/{url}",
  "UpstreamHttpMethod": [ "Get", "Put", "Delete", "Post", "Patch", "OPTIONS" ],
  "DownstreamPathTemplate": "/api/{url}",
  "DownstreamScheme": "wss",
  "DownstreamHostAndPorts": [
    {
      "Host": "apiURL.com",
      "Port": 443
    }
  ],
  "HttpHandlerOptions": {
    "AllowAutoRedirect": true
  }
},

启动代码

 app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllers();
          
            endpoints.MapHub<NotificationHub>("/api/notification");
        });

得到错误

WebSocket connection to 'wss://url.azurewebsites.net/gatewayOcelot/notification' failed: Error during WebSocket handshake: Unexpected response code: 502

【问题讨论】：

标签： azure websocket signalr ocelot

【解决方案1】：

仔细检查一下：需要在Ocelot上配置WebSocket：

 Configure(app =>
{
    app.UseWebSockets();
    app.UseOcelot().Wait();
})

在 ocelot.json 中

{
     "DownstreamPathTemplate": "/ws",
     "UpstreamPathTemplate": "/",
     "DownstreamScheme": "ws",
     "DownstreamHostAndPorts": [
         {
             "Host": "localhost",
             "Port": 5001
         }
     ],
 }

https://ocelot.readthedocs.io/en/latest/features/websockets.html#:~:text=Ocelot%20supports%20proxying%20websockets%20with,your%20application%20to%20use%20WebSockets.

【讨论】：

我已经在启动时添加了 ocelot public void Configure(IApplicationBuilder app, IWebHostEnvironment env) { app.UseWebSockets(); app.UseOcelot().Wait(); }
那么，您应该诊断并解决问题 => 应用服务计划的可用性和性能。（在 IIS 级别发生 502 错误）
诊断和解决问题：docs.microsoft.com/en-us/azure/app-service/overview-diagnostics