How to insert an entity into Azure Storage table using Web Activity of Azure Data Factory service - azure-data-factory

Question

I have a table in a storage account. I would like to do a test by inserting an entity into this table using Web Activity with the guide from this link (https://learn.microsoft.com/en-us/rest/api/storageservices/insert-entity).
I also tried to create a header in the Web Activity settings with the following format for my shared key (https://learn.microsoft.com/en-us/rest/api/storageservices/authorize-with-shared-key):
Authorization="SharedKey <_AccountName>:<_Signature>"
But it seems that there is no function in the dynamic expression to make a Hash-based Message Authentication Code (HMAC) for the <_Signature>.
Could someone give me some sample or some hints? Thanks.

Answer 1

We have a provision for using sha2 encoding in expression builder while using Data Flows.
But while using web activity in Data factory pipelines you will have to use a workaround. Here is what I tried, Call a serverless function app based on powershell to encode the signature.
basic idea in powershell:
$ClearString = "String_to_sign"
$hasher = [System.Security.Cryptography.HashAlgorithm]::Create('sha256')
$hash = $hasher.ComputeHash([System.Text.Encoding]::UTF8.GetBytes($ClearString))
$hashString = [System.BitConverter]::ToString($hash)
$body = $hashString.Replace('-', '').ToLower()
1. Call the function app:
With body: a JSON with String_to_sign
{
"name": 'pipeline().parameters.StringToSign'
}
2. Assign function app output(HMAC) to a variable: (to later encode using base64)
#activity('Azure Function1').output.Response
3. Configure WebActivity as per your scenario:
Note: I have used sample data for demonstration purpose, please use this method modifying as per your need.
Encode HMAC and prep Authorization header by using base64 function.
Authorization: #concat('SharedKey kteststoragee:',base64(variables('sha256')))
Build Authorization header following MS doc: Table service (Shared Key authorization Use string function such as Concat to build the final string.