Blazor+Dapr+K8s微服务之状态管理

1 状态管理服务器端接口

1.1 添加Dapr.AspNetCore包

在DaprTest1.Server项目中添加Dapr.AspNetCore包，该包实现了ASP.NET Core与Dapr的集成，例如自动依赖注入DaprClient对象，将状态管理功能直接集成到 ASP.NET Core 模型绑定功能中等。

修改DaprTest1.Server项目的Startup.cs文件，将Dapr对象依赖注入到ASP.NET Core。

 public void ConfigureServices(IServiceCollection services)
        {

            services.AddControllersWithViews().AddDapr();
            services.AddRazorPages();
            services.AddScoped<InvocationHandler>();

            // 注入httpClient
            services.AddHttpClient("HttpClient").AddHttpMessageHandler<InvocationHandler>()
            .AddTypedClient(client =>
            {
                client.BaseAddress = new Uri("http://serviceapi1");
                return RestService.For<ICallServiceApi1>(client);
            });
        }

在DaprTest1.Server项目的WeatherForecastController.cs文件中注入DaprClient对象

  private readonly DaprClient _daprClient;

        public WeatherForecastController(ILogger<WeatherForecastController> logger, ICallServiceApi1 callServiceApi1, DaprClient daprClient)
        {
            _logger = logger;
            _callServiceApi1 = callServiceApi1;
            _daprClient = daprClient;
        }

1.2 状态保存接口

在DaprTest1.Server项目的WeatherForecastController.cs文件中增加状态保存接口。

  [HttpPost(nameof(SaveStateValue))]
        public async Task SaveStateValue(StateModel stateModel)
        {
            await _daprClient.SaveStateAsync("statestore", stateModel.Key, stateModel.Value);
        }

其中 StateModel 为自定义的状态模型对象。

1.3 状态删除接口

在DaprTest1.Server项目的WeatherForecastController.cs文件中增加状态删除接口。

 [HttpDelete(nameof(DeleteStateValue) + "/{stateKey}")]
        public async Task DeleteStateValue(string stateKey)
        {
            await _daprClient.DeleteStateAsync("statestore", stateKey);
        }

1.4 状态获取接口

在DaprTest1.Server项目的WeatherForecastController.cs文件中增加两个状态获取接口。

 [HttpGet("GetStateValue/{stateKey}")]
        public async Task<string> GetStateValue(string stateKey)
        {
            return await _daprClient.GetStateAsync<string>("statestore", stateKey);
        }

        [HttpGet(nameof(GetStateValueFromState) + "/{stateKey}")]
        public async Task<string> GetStateValueFromState([FromState("statestore", "stateKey")] StateEntry<string> stateEntry)
        {
            return await Task.FromResult(stateEntry.Value);
        }

注意，第二个状态获取接口是通过ASP.NET Core 模型绑定实现的。

2 状态管理菜单和页面

在DaprTest1.Server项目的NavMenu.razor文件新增状态管理菜单。

 <li class="nav-item px-3">
            <NavLink class="nav-link" href="statemanage">
                <span class="oi oi-list-rich" aria-hidden="true"></span> 状态管理
            </NavLink>
        </li>

在DaprTest1.Server项目新增状态管理页面

@page "/statemanage"
@using DaprTest1.Shared
@using System.Text.Json
@inject HttpClient Http

<h1>状态存储</h1>

<p>This component demonstrates storing state.</p>

<p>状态键: TestStateKey, 状态值：<input type="text" @bind="stateModel.Value" /></p>

<button class="btn btn-primary" @onclick="SaveStateValue">保存状态</button>
<button class="btn btn-primary" @onclick="DeleteStateValue">删除状态</button>
<button class="btn btn-primary" @onclick="GetStateValue">获取状态</button>
<button class="btn btn-primary" @onclick="GetStateValueFromState">获取状态[FromState]</button>


<p>获取到的状态值: @stateValue</p>

@code {
    private StateModel stateModel = new StateModel() { Key = "TestStateKey" };
    private string stateValue = "";

    private async Task SaveStateValue()
    {
        await Http.PostAsJsonAsync<StateModel>("WeatherForecast/SaveStateValue", stateModel);
    }
    private async Task DeleteStateValue()
    {
        await Http.DeleteAsync("WeatherForecast/DeleteStateValue/" + stateModel.Key);
    }
      private async Task GetStateValue()
    {
        stateValue = await Http.GetStringAsync("WeatherForecast/GetStateValue/" + stateModel.Key);
    }
     private async Task GetStateValueFromState()
    {
        stateValue = await Http.GetStringAsync("WeatherForecast/GetStateValueFromState/" + stateModel.Key);
    }
}

3 状态管理测试

和上一节一样，我们先开启每个微服务的SideCar，然后启动两个微服务，访问状态管理页面：

我们可以查看缓存，看到状态数据，其中缓存Key是由保存状态的微服务ID+“||”+自定义的缓存Key组成，缓存内容Dapr自动增加了版本号。