Azure函数: Inherit HttpTrigger functions/routes from base class

Question

我在许多 Azure Function 应用程序中拥有一些常见功能。每个 Function App 在每个 Function App 拥有的公共(public)资源上公开完全相同的查询操作。相同的端点、相同的依赖关系等。到目前为止，已经有大量的复制粘贴来维持这种情况。

因此，我将其重构为一个基本抽象类，该类位于所有服务使用的公共(public)项目中。它看起来像这样:

    public abstract class DeadLetterApiBaseFunction : BaseFunction
    {
        private readonly IDeadLetterBlobClient _deadLetterBlobClient;
        private readonly string ROLE_READ;
        private readonly string ROLE_WRITE;
        private readonly ILogger _logger;

        public DeadLetterApiBaseFunction(
            ILogger logger,
            IMiddlewareService middleware,
            IDeadLetterBlobClient deadLetterBlobClient,
            string ROLE_READ,
            string ROLE_WRITE) : base(logger, middleware)
        {
            _logger = logger;
            _deadLetterBlobClient = deadLetterBlobClient;
            this.ROLE_READ = ROLE_READ;
            this.ROLE_WRITE = ROLE_WRITE;
        }

        [FunctionName(nameof(GetDeadLetterBlobItemsForContainer))]
        [ProducesResponseType(typeof(ResponsePayload<List<BlobItemWithContent>>), Status200OK)]
        [ProducesResponseType(Status500InternalServerError)]
        [ProducesResponseType(Status400BadRequest)]
        [QueryStringParameter("container", "Name of the container", DataType = typeof(string))]
        public async Task<ActionResult<ResponsePayload<List<BlobItemWithContent>>>> GetDeadLetterBlobItemsForContainer(
            [HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = "v1/dead-letters/blobs-for-container")]
            HttpRequest request)
        {
            // .... do stuff 
        }
    }
}

这个想法是每个服务都会像这样子类化:

    public class DeadLetterApiFunction : DeadLetterApiBaseFunction
    {
        public DeadLetterApiFunction(
            ILogger<DeadLetterApiFunction> logger,
            IMiddlewareService middleware,
            IDeadLetterBlobClient deadLetterBlobClient) : base(
                logger: logger, 
                middleware: middleware, 
                deadLetterBlobClient: deadLetterBlobClient,
                ROLE_READ: "blarg",
                ROLE_WRITE: "blarg2")
        {
        }
    }

看起来很棒吧？但是，当您运行该函数时，端点不会被公开 - 不会检测到该函数。

有没有办法获取从基类公开的 Azure Functions HttpTrigger 函数？或者只是不支持？我们使用 .NET Core 3.1 和 Azure Functions 3。

这里有一个相关的问题，但答案采取了不同的路径:

Use Azure Functions in abstract base class?

Answer 1

由于 HTTP 触发器是特定路由的单一入口点，因此我将在单独的类中抽象出 HTTP 触发器，然后在创建为单例时将其注入(inject)到 DeadLetterApiFunction 类中Startup.cs 文件。这是可能的，因为 Azure 函数支持实例函数来启用 D​​I。

public class HttpTrigger
{
    public HttpTrigger()
    {
    }

    [FunctionName(nameof(GetDeadLetterBlobItemsForContainer))]
    [ProducesResponseType(typeof(ResponsePayload<List<BlobItemWithContent>>), Status200OK)]
    [ProducesResponseType(Status500InternalServerError)]
    [ProducesResponseType(Status400BadRequest)]
    [QueryStringParameter("container", "Name of the container", DataType = typeof(string))]
    public async Task<ActionResult<ResponsePayload<List<BlobItemWithContent>>>> GetDeadLetterBlobItemsForContainer(
        [HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = "v1/dead-letters/blobs-for-container")]
        HttpRequest request)
    {
        // .... do stuff 
    }
}