Retention Policy for Azure Containers?

Question

I'm looking to set up a policy for one of my containers so it deletes or only retains data for x days. So if x is 30, that container should only contain files that are less than 30 days old. If the files are sitting in the container for more than 30 days it should discard them. Is there any way I can configure that?

Answer 1

Currently such kind of thing is not supported by Azure Blob Storage. You would need to write something of your own that would run periodically to do this check and delete old blobs.

On a side note, this feature has been long pending (since 2011): https://feedback.azure.com/forums/217298-storage/suggestions/2474308-provide-time-to-live-feature-for-blobs.

UPDATE

If you need to do it yourself, there are two things to consider:

1. Code to fetch the list of blobs, find out the blobs that need to be deleted and then delete those blobs. To do this, you can use Azure Storage SDK. Azure Storage SDK is available for many programming languages like .Net, Java, Node, PHP etc. You just need to use the one that you're comfortable with.
2. Schedule this code to run once on a daily basis: To do this, you can use one of the many services available in Azure. You can use Azure WebJobs, Functions, Schedular, Azure Automation etc.

If you decide to use Azure Automation, there's a Runbook already available for you that you can use (no need to write your code). You can find more details about this here: https://gallery.technet.microsoft.com/scriptcenter/Remove-Storage-Blobs-that-aae4b761.

Answer 2

Azure Blob storage Lifecycle (Preview) is now available and using that we create Policies with different rules.

Here is the rule to delete the blobs which are older than 30 days

 {
  "version": "0.5",
  "rules": [
    {
      "name": "expirationRule",
      "type": "Lifecycle",
      "definition": {
        "filters": {
          "blobTypes": [ "blockBlob" ]
        },
        "actions": {
          "baseBlob": {
            "delete": { "daysAfterModificationGreaterThan": 30}
          }
        }
      }
    }
  ]
}

For more details refer this Azure Blob storage Lifecycle