Azure Function - writing and reading a blob file

Question

This is my first post, pleas excuse me if i have made an errors.

I am very new to Azure.

I have created a function that is triggered by ASA using Service bus Queue.

My data is passed into the function.

I would like to know how i can create a blob file , the file name must be specific to a certain string.

I would then like to write to the file or even read from the file.

Are there any samples of writing and reading to files using Azure functions? I am correct i must use a binding process.

Thank You

DJ

Answer 1

Are there any samples of writing and reading to files using Azure functions? I am correct i must use a binding process.

To bind Blob to your function, you need to add following configure section to function.json. The direction must be set to 'inout' if you want to read and write data to the blob.

{
  "type": "blob",
  "name": "myBlob",
  "path": "mycontainer/myblob.txt",
  "connection": "your_azurestorage_connection_name",
  "direction": "inout"
}

After that, you could add a parameter to your function named myBlob.

public static async Task Run(CloudBlockBlob myBlob, TraceWriter log)
{
}

Since the type of CloudBlockBlob is not default imported to Azure function, we need to add following code to import it.

#r "Microsoft.WindowsAzure.Storage"
using Microsoft.WindowsAzure.Storage.Blob;

At the last, we can read or write data to the blob using the myBlob reference. Sample of writing data to the blob.

byte[] buffer = System.Text.Encoding.UTF8.GetBytes("hello world!");
myBlob.UploadFromByteArray(buffer, 0, buffer.Length);