Hi Ethan,

I've done something similar before and this would depend on whether you're using Azure or not. If you are, then you can do something like this:

public class AzureBlobCacheDeleter
{
	private static CloudBlobContainer _container;
	private readonly IContentLoader _contentLoader;

	private const string prefix = "3p!_";

	private readonly ILogger _logger = LogManager.GetLogger(typeof(AzureBlobCacheDeleter));

	public AzureBlobCacheDeleter(IContentLoader contentLoader)
	{
		TrySetCloudBlobContainer();
		_contentLoader = contentLoader;
	}

	public void TrySetCloudBlobContainer()
	{
		try
		{
			var provider = EPiServerFrameworkSection.Instance.Blob.Providers[EPiServerFrameworkSection.Instance.Blob.DefaultProvider];

			string connectionString = ConfigurationManager.ConnectionStrings[provider.Parameters[AzureBlobProvider.ConnectionStringNameKey]].ConnectionString;

			string containerName = provider.Parameters[AzureBlobProvider.ContainerKey];

			_container = CloudStorageAccount.Parse(connectionString).CreateCloudBlobClient().GetContainerReference(containerName);
		}
		catch (Exception ex)
		{
			_logger.Error("Failed to resolve an Azure blob service container.", ex);
		}
	}

	public bool TryDeleteCachedImages(ContentReference imageLink)
	{
		if (ContentReference.IsNullOrEmpty(imageLink))
		{
			return false;
		}

		if (_container == null)
		{
			// This can only be run on environment with a configured Azure blob service container.
			return false;
		}

		if (!_contentLoader.TryGet<MediaData>(imageLink, out var mediaData))
		{
			return false;
		}

		var binaryDataContainer = mediaData.BinaryDataContainer;

		var segment = binaryDataContainer.Segments[1];

		if (string.IsNullOrEmpty(segment))
		{
			return false;
		}

		var results = _container.ListBlobs(segment, true, BlobListingDetails.None);

		foreach (var blob in results.OfType<CloudBlockBlob>())
		{
			if (!blob.Name.Contains(prefix))
			{
				continue;
			}


			CacheIndexer.Remove(blob.Name);
			blob.Delete();
		}

		return true;
	}
}

This is essentially based on looking into how the AzureBlobCache works (ImageProcessor.Web.Episerver.Azure). If you're using the FileBlobCache (ImageProcessor.Web.Episerver) I'd imagine you'd do something very similar, but I don't have a code snippet for that. 😊 I'd probably start by looking at the code (https://github.com/vnbaaij/ImageProcessor.Web.Episerver/blob/master/src/ImageProcessor.Web.Episerver/FileBlobCache.cs) especially the TrimCacheAsync method.

Good luck!