在 Azure Function v3 中获取连接字符串

Question

我很困惑。我想在 Azure v3 函数 (.Net Core 3.1) 中获取连接字符串。

我的本地设置看起来像

{
    "IsEncrypted": false,
    "Values": {
        "AzureWebJobsStorage": "UseDevelopmentStorage=true",
        "AzureWebJobsDashboard": "UseDevelopmentStorage=true"
    },
    "ConnectionStrings": {
      "DefaultConnection": "bla bla"
    }
}

在我做的函数中

string defaultConnection = Environment.GetEnvironmentVariable("ConnectionStrings:DefaultConnection");

这在本地运行良好，但在 Azure 上，defaultConnection 为空。我在函数的应用程序设置的连接字符串部分下定义了连接。

我的方法对 Azure Function v3 正确吗？

Answer 1

请注意

Connection strings should only be used with a function app if you are using entity framework. For other scenarios use App Settings.

所以如果你只是想获取DefaultConnection的值，可以把它放在Application settings下，这样就可以获取了

Environment.GetEnvironmentVariable("DefaultConnection");

Entity Framework的Azure功能请参考this article。

Answer 2

您需要指定连接字符串前缀（参见 documentation）：

Environment.GetEnvironmentVariable("CUSTOMCONNSTR_DefaultConnection");

Answer 3

如果您使用的是 Microsoft.NET.Sdk.Functions 3.0.11 和 Microsoft.Azure.Functions.Extensions 1.1.0，并且您使用的是具有依赖注入的 Azure Functions，则可以执行以下操作来访问连接字符串（或任何配置）启动应用程序时。

using Microsoft.Azure.Functions.Extensions.DependencyInjection;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Configuration.AzureAppConfiguration;
using System;

[assembly: FunctionsStartup(typeof(YourNamespace.Startup))]

namespace YourNamespace
{
    public class Startup : FunctionsStartup
    {
        public IConfiguration Configuration { get; set;  }

        public override void ConfigureAppConfiguration(IFunctionsConfigurationBuilder builder)
        {
            var config = builder.ConfigurationBuilder.Build();

            // This can be used to get a connection string from local.settings.json and also works when deployed to Azure
            var appConfigConnection = config.GetConnectionString("AppConfig");
            // This is to access the environment variables. 
            var environment = Environment.GetEnvironmentVariable("Environment");

            // This particular example uses the values retrieved to bootstrap Azure App Configuration
            builder.ConfigurationBuilder.AddAzureAppConfiguration(options =>
            {
                options.Connect(appConfigConnection).Select(KeyFilter.Any, environment.ToLowerInvariant());
            });
        }

        public override void Configure(IFunctionsHostBuilder builder)
        {
            // In case you need to access IConfiguration
            Configuration = builder.GetContext().Configuration;
        }
    }
}

样本local.setting.json

{
  "IsEncrypted": false,
  "Values": {
    "FUNCTIONS_WORKER_RUNTIME": "dotnet",
    "AzureWebJobsStorage": "your connection string",
    "Environment": "Development"
  },  
  "ConnectionStrings": {
    "AppConfig": "your connection string"
  }
}

在 Azure Function v3 中获取连接字符串

Get Connection String in Azure Function v3

c#

asp.net-core

azure-functions

connection-string

application-settings