如何在 Azure 函数中获取用户密码？答案

【问题标题】：How to get a usersecret in an Azure Function?如何在 Azure 函数中获取用户密码？
【发布时间】：2021-11-20 07:59:40
【问题描述】：

我需要从 usersecrets 中获取连接字符串。我尝试过这样：

CosmosClient cosmos = new CosmosClient("CosmosConnectionString", new CosmosClientOptions
        {
            ConnectionMode = ConnectionMode.Gateway
        });

但这不起作用，因为 CosmosClient 只能理解文字字符串。我尝试用 usersecrets 注入 Azure Functions，为此我创建了一个启动类：

    [assembly: FunctionsStartup(typeof(Startup))]
namespace AltProject
{
    public class Startup : FunctionsStartup
    {
        // override configure method
        public override void Configure(IFunctionsHostBuilder builder)
        {
            var config = new ConfigurationBuilder()
               .SetBasePath(Environment.CurrentDirectory)
               .AddJsonFile("appsettings.json", true)
               .AddUserSecrets(Assembly.GetExecutingAssembly(), false)
               .AddEnvironmentVariables()
               .Build();
           
            builder.Services.AddSingleton<IConfiguration>(config);
            foreach (DictionaryEntry de in Environment.GetEnvironmentVariables())
                Console.WriteLine("  {0} = {1}", de.Key, de.Value);            // register your other services
        }
    }

}

然后我尝试在 CosmosClient 中以这种方式获取连接字符串：

      CosmosClient cosmos = new CosmosClient(System.Environment.GetEnvironmentVariable("CosmosConnectionString", EnvironmentVariableTarget.Process), new CosmosClientOptions
        {
            ConnectionMode = ConnectionMode.Gateway
        });

但这没有给我任何结果，似乎环境值没有注入用户机密。有没有办法让这个工作？

【问题讨论】：

标签： c# azure-functions azure-cosmosdb

【解决方案1】：

完整示例位于：https://github.com/Azure/azure-cosmos-dotnet-v3/tree/master/Microsoft.Azure.Cosmos.Samples/Usage/AzureFunctions

您应该能够毫无问题地读取 Startup 中的配置。假设您的 appsettings.json 包含一个名为 CosmosConnectionString 的密钥，或者您通过 Functions App Settings 添加它：

[assembly: FunctionsStartup(typeof(AltProject.Startup))]
namespace AltProject
{
    private static readonly IConfigurationRoot configuration = new ConfigurationBuilder()
                .SetBasePath(Environment.CurrentDirectory)
                .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                .AddEnvironmentVariables()
                .Build();

    public override void Configure(IFunctionsHostBuilder builder)
    {
        builder.Services.AddSingleton((s) => {
            string connectionString = configuration["CosmosConnectionString"];
            if (string.IsNullOrEmpty(connectionString))
            {
                throw new ArgumentNullException("CosmosConnectionString empty or not set at appsettings.json file or your Azure Functions Settings.");
            }

            return new CosmosClient(connectionString, new CosmosClientOptions
            {
                ConnectionMode = ConnectionMode.Gateway
            });
        });
    }
}

然后您可以在您的函数中注入CosmosClient：

public class MyFunction
{
    private CosmosClient cosmosClient;
    public MyFunction(CosmosClient cosmosClient)
    {
        this.cosmosClient = cosmosClient;
    }


    [FunctionName("CosmosClient")]
    public async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
        ILogger log)
    {
        // use this.cosmosClient
    }
}

【讨论】：