Azure事件网格订阅WebHook验证在Cloud Events Schema v1.0中失败

Question

尝试创建WebHook订阅时，部署无法验证云事件1.0版架构的Azure函数中的HTTP触发器。我已经确认我的endpoint用适当的响应处理了验证握手。我的事件网格域使用的是云事件1.0版模式。看起来我的Azure函数在验证期间甚至没有被调用，因为在函数的控制台中没有输出。

这应该适用于 Cloud Events v1.0 和 WebHooks 吗？

部署失败，出现以下错误:{"code":"Url验证"，" message ":"尝试验证提供的endpointxxxxx失败。"}

这是我的代码：

[FunctionName("ProcessEvent")]
        public static async Task<HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequestMessage req, ILogger log)
        {
            log.LogInformation("C# HTTP trigger function processed a request.");

            var requestmessage = await req.Content.ReadAsStringAsync();
            var message = JToken.Parse(requestmessage);

            if (message.Type == JTokenType.Array)
            {
                // If the request is for subscription validation, send back the validation code.
                if (string.Equals((string)message[0]["eventType"],
                "Microsoft.EventGrid.SubscriptionValidationEvent",
                System.StringComparison.OrdinalIgnoreCase))
                {
                    log.LogInformation("Validate request received");

                    var myObj = new { validationResponse = message[0]["data"]["validationCode"].ToString() };
                    var jsonToReturn = JsonConvert.SerializeObject(myObj);

                    return new HttpResponseMessage(HttpStatusCode.OK)
                    {
                        Content = new StringContent(jsonToReturn, Encoding.UTF8, "application/json")
                    };
                }
            }
            else
            {
                // The request is not for subscription validation, so it's for an event.
                // CloudEvents schema delivers one event at a time.
                log.LogInformation($"Source: {message["source"]}");
                log.LogInformation($"Time: {message["eventTime"]}");
                log.LogInformation($"Event data: {message["data"].ToString()}");
            }

            return req.CreateResponse(HttpStatusCode.OK);
}

Answer 1

CloudEvents v1.0的endpoint验证不同于此处描述的EventGridSchema和CustomInputSchema等交付模式。

出于测试目的，您可以将Webhook.site用于endpoint处理程序。以下屏幕显示了EventGrid为其验证握手发送OPTIONS调用：

注意，endpoint处理程序的地址必须是https。上图可以看到，有一个webhook-request-callback头。复制它的值a放在浏览器上发送。您应该得到以下文本:

"Webhook succesfully validated as a subscription endpoint."

从现在开始，webhook可以收到一条通知消息，参见如下屏幕:

如您所见，CloudEvent v1.0需要为endpoint验证实现HTTP选项响应。以下是此实现的示例：

string webhookcallback = req.Headers.GetValues("WebHook-Request-Callback")?.FirstOrDefault()?.Trim();       
if(string.IsNullOrEmpty(webhookcallback) == false)
{
    var hrm2 = req.CreateResponse(HttpStatusCode.OK);
    hrm2.Headers.Add("WebHook-Request-Origin", "eventgrid.azure.net");
    hrm2.Headers.Add("WebHook-Allowed-Rate", "120");

    System.Threading.ThreadPool.QueueUserWorkItem(delegate (object state)
    {
        Task.Delay(5000).Wait();
        using(var client = new HttpClient())
        {
            log.Warning($"{client.GetAsync(webhookcallback).Result.Content.ReadAsStringAsync().Result}");
        }
    });

    return hrm2;
}

将上述代码片段放入您的函数中。请注意，调用WebHook-Request est-Callback地址不能在OPTIONS调用中，它必须在其OK响应返回EventGrid后完成，因此我们有一些延迟和后台线程。如果EventGrid在OPTIONS调用中接受此调用，那就太好了。