Function to retrieve deleted blobs and put them in a queue

azfuncRetrieveDeletedBlobs.cs

using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Azure.WebJobs.Host;
using System.Threading.Tasks;
using System.Collections.Generic;
using Microsoft.WindowsAzure.Storage.Blob;
using Microsoft.WindowsAzure.Storage;
using System.Linq;
using System;

namespace SearchFunctions
{
    public static class Function1
    {
        [FunctionName("RetrieveDeletedBlobs")]
        public static async Task<ICollector<string>> Run(
            [HttpTrigger(AuthorizationLevel.Function, "get", Route = null)]HttpRequest req,
            [Queue("blobs-to-delete", Connection = "StorageQueueConnectionString")] ICollector<string> outputQueueItems,
            TraceWriter log)
        {
            log.Info("Adding blobs to the delete queue");
            var deletedBlobUris = await ListAllDeletedBlobUris();
            foreach (var blobUri in deletedBlobUris)
            {
                outputQueueItems.Add(blobUri);
            }

            return outputQueueItems;
        }

        private static async Task<List<string>> ListAllDeletedBlobUris()
        {
            var sa = CloudStorageAccount.Parse(Environment.GetEnvironmentVariable("StorageBlobConnectionString"));
            var blobClient = sa.CreateCloudBlobClient();
            var container = blobClient.GetContainerReference("searchdata");
            var results = await ListBlobsAsync(container);

            var deletedBlobs = results.Cast<CloudBlockBlob>()
                .Where(b => b.Metadata["IsDeleted"] == "false");

            return deletedBlobs.Select(b => b.Uri.AbsoluteUri).ToList();
        }

        public static async Task<List<IListBlobItem>> ListBlobsAsync(CloudBlobContainer container)
        {
            BlobContinuationToken continuationToken = null;
            List<IListBlobItem> results = new List<IListBlobItem>();
            do
            {
                var response = await container.ListBlobsSegmentedAsync(
                    null, 
                    false, 
                    BlobListingDetails.Metadata, 
                    null, 
                    continuationToken, 
                    null, null);
                continuationToken = response.ContinuationToken;
                results.AddRange(response.Results);
            }
            while (continuationToken != null);

            return results;
        }
    }
}