Data Lake Gen 2 的 Azure Blob 触发器函数

Question

What i am trying to do? I have a data lake container. inside HDFS name spaces ex: "container/year/month/day/bunch of files". files will upload on daily bases and folder structure is dynamic based on current date . i need my azure function to trigger when files are uploaded in day directory. and those files will process and dump data to sql server db[c# code]. Only i have problem is triggering my function over dynamic directory. please help me or suggest me on how to approach.

Thanks a million.

Answer 1

You don't need to use dynamic foldername. Actually, the path of the blobtrigger need to be given when compiled. You should give a const or set it in the environment variable.

So, two ways:

1, The first way is simply. Just do like this:

using System;
using System.IO;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Host;
using Microsoft.Extensions.Logging;

namespace FunctionApp23
{
    public static class Function1
    {
        [FunctionName("Function1")]
        public static void Run([BlobTrigger("yourcontainername/{year}/{month}/{day}/{filename}", Connection = "str")]Stream myBlob, string filename, ILogger log)
        {
            log.LogInformation($"C# Blob trigger function Processed blob\n Name:{filename} \n Size: {myBlob.Length} Bytes");
        }
    }
}

2, Second way, Deploy a timetrigger with your blobtrigger. And put the code that can add the environment variable in it.(This timetrigger triggers once a day.)

I don't recommend this method, Although it can achieve the "dynamic", but I think your use case does not need this. If you really need this, I will update the code. But in theory the first method is sufficient.