Get Max File Size for Azure Storage Container

Recently, I got a request from a coworker to determine the maximum file size we have in an Azure Storage container. This seemed simple enough, but I didn’t find a quick solution, so I decided to publish something myself. I had 2 criteria to fulfill for the solution. First, I wanted to use the Azure CLI (I don’t use it as often as I’d like, so I try to find oportunities when I can). The second was to use a JMESPath query. Because I don’t use either very often, it took a few minutes to get the syntax just right.

The way I did all this was through the Azure Cloud Shell via Windows Terminal.

And here’s the snippet:

$b = $(az storage blob list --account-name STORAGE_ACCOUNT_NAME --container-name CONTAINER_NAME --query "max([].properties.contentLength)"); 
$mb = $b/1Mb;
Write-Host "Largest file: $($mb)Mb ($($b) bytes)";

You can always use az interactive to help with syntax on the CLI commands, as it will provide some intellisense. I find it very helpful for getting things going quickly. The JMESpath queries can be a bit hit or miss, and I have to remind myself of the syntax everytime. Thankfully, the website has some good examples.