[DurableTask.ServiceBus] List only containers starting with prefix (#1240)

Author: solankisamir

src/DurableTask.ServiceBus/Tracking/BlobStorageClient.cs

@@ -136,10 +136,16 @@ private async Task<BlobClient> GetCloudBlobClientAsync(string containerNameSuffi
         public async Task<IEnumerable<BlobContainerItem>> ListContainersAsync()
         {
             List<BlobContainerItem> results = new List<BlobContainerItem>();
-            var response = this.blobServiceClient.GetBlobContainersAsync();
+            // Use the service client's prefix parameter to only enumerate containers that start with the
+            // configured containerNamePrefix. Also apply a defensive in-memory filter in case of any
+            // unexpected differences in casing or service behavior.
+            var response = this.blobServiceClient.GetBlobContainersAsync(prefix: this.containerNamePrefix);
             await foreach (var container in response)
             {
-                results.Add(container);
+                if (container.Name != null && container.Name.StartsWith(this.containerNamePrefix, StringComparison.OrdinalIgnoreCase))
+                {
+                    results.Add(container);
+                }
             }
             return results;
         }

test/DurableTask.ServiceBus.Tests/BlobStorageClientTest.cs

@@ -102,5 +102,33 @@ public async Task TestDeleteContainers()
             containers = (await this.blobStorageClient.ListContainersAsync()).ToList();
             Assert.AreEqual(0, containers.Count);
         }
+
+        [TestMethod]
+        public async Task TestListContainersOnlyWithPrefix()
+        {
+            // Create a container that does NOT use the current client's prefix
+            string storageConnectionString = TestHelpers.GetTestSetting("StorageConnectionString");
+            var serviceClient = new BlobServiceClient(storageConnectionString);
+
+            string otherHub = "otherhubprefix" + Guid.NewGuid().ToString("N").Substring(0, 8);
+            string otherPrefix = BlobStorageClientHelper.BuildContainerNamePrefix(otherHub);
+            string otherContainerName = BlobStorageClientHelper.BuildContainerName(otherPrefix, "message-20100101");
+
+            var otherContainer = serviceClient.GetBlobContainerClient(otherContainerName);
+            await otherContainer.CreateIfNotExistsAsync();
+
+            try
+            {
+                // Ensure the externally-created container is not returned by the client's listing
+                List<BlobContainerItem> containers = (await this.blobStorageClient.ListContainersAsync()).ToList();
+                Assert.IsFalse(containers.Any(c => string.Equals(c.Name, otherContainerName, StringComparison.OrdinalIgnoreCase)),
+                    "ListContainersAsync returned a container that does not match the client's prefix.");
+            }
+            finally
+            {
+                // Clean up the external container explicitly
+                await otherContainer.DeleteIfExistsAsync();
+            }
+        }
     }
 }