无法删除触发 Azure 函数 Blob 输入绑定的 Blob

Question

This is a follow-up question to this question:

How to delete a blob using Azure Functions?

When a blob triggers my Azure Function, I need to delete it once its processing is done. Otherwise, I will end up with many blobs in the container.

When I run the following code:

CloudStorageAccount storageAccount = CloudStorageAccount.Parse(connection);
var blobClient = storageAccount.CreateCloudBlobClient();
var container = blobClient.GetContainerReference("process");
var blockBlob = container.GetBlockBlobReference($"process/in/{name}"); // ==> This was the problem. See the answer for more info. 
bool deleted = blockBlob.DeleteIfExists();

the method blockBlob.DeleteIfExists() always returns false and it never deletes the blob.

My guess is that the blob is somehow locked by the function execution since it just triggered it.

[Update 1]

...

[Update 2]

Many thanks to @Jerry Liu, the issue had nothing to do with Azure Fundctions.

The trick is that blockBlob.DeleteIfExists() returns false when caller sends a wrong path by mistake.

A better approach could be using 'blockBlob.Delete' and find out what is the actual issue.

See DeleteIfExists source code for more info.

https://github.com/Azure/azure-storage-net/blob/master/Lib/ClassLibraryCommon/Blob/CloudBlob.cs#L1993

Another related question: Azure CloudBlockBlob.DeleteIfExists() - Does false always mean the blob doesn't exist?

Answer 1

Problem locates at this line

var blockBlob = container.GetBlockBlobReference($"process/in/{name}");

The blob name should be $"in/{name}" because we call GetBlockBlobReference based on specific container which we have already got in GetContainerReference .

The duplicate causes Storage fail to find the blob. We may be confused about no related prompt/exception because DeleteIfExists also return false when blob doesn't exist.