Dapr + .NET Core實戰（十一）單機Dapr集群負載均衡

4小時Dapr+.NET 5+K8S 的實戰  https://ke.qq.com/course/4000292?tuin=1271860f

Dapr進階虛擬機集群實戰（非K8S） https://ke.qq.com/course/4002149?tuin=1271860f

                   

如何單機部署Dapr集群

第十篇講過了K8S集群下如何使用Dapr運行程序，但是很多人一直在問如何單機下進行Dapr的負載，這節課我們來聊聊如何單機進行Dapr的負載。

首先要說的是單機下，通過 dapr run --app-id xxxxx這個命令是沒辦法直接運行dapr集群的，因為同一個app-id只能通過dapr run運行一次。這時候我們就需要利用docker來實現dapr的單機集群部署。下面我們就來實現dapr的單機集群部署。

 

項目拓撲

 

 我們采用在docker內部為frontend部署一個實例，為backend部署兩個實例的方法，來實現backend的集群化負載，另外需要為frontend和2個backend分別啟動一個sidecar容器。因此此實例一共需要部署6個容器。

項目實戰

首先在BackEnd中新增控制器IpController，並添加獲取backend實例ip的接口

   [Route("api/[controller]")]
    [ApiController]
    public class IpController : ControllerBase
    {
        public ActionResult Get()
        {
            var ip = System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces().Select(p => p.GetIPProperties()).SelectMany(p => p.UnicastAddresses)
                      .Where(p => p.Address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork && !System.Net.IPAddress.IsLoopback(p.Address))
                      .FirstOrDefault()?.Address.ToString();

            return Ok(new List<string> { ip });
        }

    }

 

然后需要在FrontEnd的DaprController中添加調用獲取backend ip的接口

        [HttpGet("ip")]
        public async Task<ActionResult> GetIpAsync()
        {
            using var _daprClient = new DaprClientBuilder().Build();
            var result = await _daprClient.InvokeMethodAsync<List<string>>(HttpMethod.Get, "backend", "api/Ip");
            return Ok(result);
        }

 

這樣我們就可以通過訪問frontend的Dapr/ip來驗證backend是不是可以實現負載均衡。

Docker運行

在前面的課程里我們已經為backend和frontend建好了Dockerfile，這里不再談Dockerfile的編寫

backend

#See https://aka.ms/containerfastmode to understand how Visual Studio uses this Dockerfile to build your images for faster debugging.

FROM mcr.microsoft.com/dotnet/aspnet:5.0 AS base WORKDIR /app EXPOSE 5000 FROM mcr.microsoft.com/dotnet/sdk:5.0 AS build WORKDIR /src COPY ["BackEnd/BackEnd.csproj", "BackEnd/"] RUN dotnet restore "BackEnd/BackEnd.csproj" COPY . . WORKDIR "/src/BackEnd" RUN dotnet build "BackEnd.csproj" -c Release -o /app/build FROM build AS publish RUN dotnet publish "BackEnd.csproj" -c Release -o /app/publish FROM base AS final WORKDIR /app COPY --from=publish /app/publish . ENTRYPOINT ["dotnet", "BackEnd.dll"]

frontend

#See https://aka.ms/containerfastmode to understand how Visual Studio uses this Dockerfile to build your images for faster debugging.

FROM mcr.microsoft.com/dotnet/aspnet:5.0 AS base WORKDIR /app EXPOSE 5001 FROM mcr.microsoft.com/dotnet/sdk:5.0 AS build WORKDIR /src COPY ["FrontEnd/FrontEnd.csproj", "FrontEnd/"] RUN dotnet restore "FrontEnd/FrontEnd.csproj" COPY . . WORKDIR "/src/FrontEnd" RUN dotnet build "FrontEnd.csproj" -c Release -o /app/build FROM build AS publish RUN dotnet publish "FrontEnd.csproj" -c Release -o /app/publish FROM base AS final WORKDIR /app COPY --from=publish /app/publish . ENTRYPOINT ["dotnet", "FrontEnd.dll"]

右鍵backend新增容器適配支持，新增docker-compose支持

 

 修改docker-compose.yaml的內容

version: '3.4'
services:
  backend:
    image: ${DOCKER_REGISTRY-}backend build: context: . dockerfile: BackEnd/Dockerfile ports: - "51000:50001" daprbackend-dapr: image: "daprio/daprd:latest" command: [ "./daprd", "-app-id", "backend", "-app-port", "5000" ] depends_on: - backend network_mode: "service:backend" backend2: image: ${DOCKER_REGISTRY-}backend2 build: context: . dockerfile: BackEnd/Dockerfile ports: - "53000:50001" daprbackend-dapr2: image: "daprio/daprd:latest" command: [ "./daprd", "-app-id", "backend", "-app-port", "5000" ] depends_on: - backend2 network_mode: "service:backend2" frontend: image: ${DOCKER_REGISTRY-}frontend build: context: . dockerfile: FrontEnd/Dockerfile ports: - "54000:50001" - "5001:5001" daprfrontend-dapr: image: "daprio/daprd:latest" command: [ "./daprd", "-app-id", "frontend", "-app-port", "5001" ] depends_on: - frontend network_mode: "service:frontend"

其中我們公開了frontend和backend的50001默認GRPC通信端口，給frontend暴露了一個5001端口，另外給backend和frontend分別啟動了一個daprd容器，通過depends_on和network_mode實現綁定。

運行並驗證

我們通過docker-compose up -d 來運行

docker-compose up -d

看到以下內容則啟動成功

Creating dapr-aspnetcore-demo_backend2_1         ... done
Creating dapr-aspnetcore-demo_backend_1 ... done Creating dapr-aspnetcore-demo_frontend_1 ... done Creating dapr-aspnetcore-demo_daprbackend-dapr_1 ... done Creating dapr-aspnetcore-demo_daprbackend-dapr2_1 ... done Creating dapr-aspnetcore-demo_daprfrontend-dapr_1 ... done

通過postman調用frontend的dapr/ip，發現返回的backend的ip不一致，已成功實現負載均衡