Verify that storage queue to monitor exists

samples/promitor-sample.yaml

@@ -36,8 +36,8 @@ metrics:
         # Optionally override the default aggregation interval (metricDefaults.aggregation.interval)
         interval: 00:15:00
   - name: demo_azurestoragequeue_queue_size
-    description: "Approximate amount of messages in 'testqueue' queue (determined with AzureStorageQueue provider)"
-    resourceType: AzureStorageQueue
+    description: "Approximate amount of messages in 'testqueue' queue (determined with StorageQueue provider)"
+    resourceType: StorageQueue
     accountName: testaccount
     queueName: testqueue
     sasToken: "?sv=2015-04-05&si=read&sig=zs87c3nUp1uiF4UAMMstXrLKhIpGOirFHRcQ4XYxxpY%3D"

src/Promitor.Core.Scraping/ResourceTypes/StorageQueueScraper.cs

@@ -10,7 +10,7 @@
 
 namespace Promitor.Core.Scraping.ResourceTypes
 {
-    public class StorageQueueScraper: Scraper<StorageQueueMetricDefinition>
+    public class StorageQueueScraper : Scraper<StorageQueueMetricDefinition>
     {
         private readonly AzureStorageQueueClient _azureStorageQueueClient;
         public StorageQueueScraper(AzureMetadata azureMetadata, MetricDefaults metricDefaults, AzureMonitorClient azureMonitorClient, ILogger logger, IExceptionTracker exceptionTracker)

src/Promitor.Integrations.AzureStorage/AzureStorageClient.cs

@@ -0,0 +1,25 @@
+using GuardNet;
+using Microsoft.WindowsAzure.Storage;
+using Microsoft.WindowsAzure.Storage.Auth;
+
+namespace Promitor.Integrations.AzureStorage
+{
+    public class AzureStorageClient
+    {
+        /// <summary>
+        ///     Authenticate with Azure Storage
+        /// </summary>
+        /// <param name="accountName">Name of the storage account</param>
+        /// <param name="sasToken">SAS token to authenticate with</param>
+        /// <returns>Authenticated storage account</returns>
+        protected CloudStorageAccount AuthenticateWithSasToken(string accountName, string sasToken)
+        {
+            Guard.NotNullOrEmpty(accountName, nameof(accountName));
+            Guard.NotNullOrEmpty(sasToken, nameof(sasToken));
+
+            var storageCredentials = new StorageCredentials(sasToken);
+
+            return new CloudStorageAccount(storageCredentials, accountName, endpointSuffix: null, useHttps: true);
+        }
+    }
+}

src/Promitor.Integrations.AzureStorage/AzureStorageQueueClient.cs

@@ -1,12 +1,11 @@
 using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
-using Microsoft.WindowsAzure.Storage;
-using Microsoft.WindowsAzure.Storage.Auth;
 using Microsoft.WindowsAzure.Storage.Queue;
+using Promitor.Integrations.AzureStorage.Exceptions;
 
 namespace Promitor.Integrations.AzureStorage
 {
-    public class AzureStorageQueueClient
+    public class AzureStorageQueueClient : AzureStorageClient
     {
         private readonly ILogger _logger;
 
@@ -29,15 +28,21 @@ public AzureStorageQueueClient(ILogger logger)
         public async Task<int> GetQueueMessageCountAsync(string accountName, string queueName, string sasToken)
         {
             var queue = GetQueueReference(accountName, queueName, sasToken);
+            var doesQueueExist = await queue.ExistsAsync();
+            if (doesQueueExist == false)
+            {
+                throw new QueueNotFoundException(queueName);
+            }
+
             await queue.FetchAttributesAsync();
             var messageCount = queue.ApproximateMessageCount ?? 0;
             _logger.LogInformation("Current size of queue {0} is {1}", queueName, messageCount);
             return messageCount;
         }
 
-        private static CloudQueue GetQueueReference(string accountName, string queueName, string sasToken)
+        private CloudQueue GetQueueReference(string accountName, string queueName, string sasToken)
         {
-            var account = new CloudStorageAccount(new StorageCredentials(sasToken), accountName, null, true);
+            var account = AuthenticateWithSasToken(accountName, sasToken);
             var queueClient = account.CreateCloudQueueClient();
             return queueClient.GetQueueReference(queueName);
         }

src/Promitor.Integrations.AzureStorage/Exceptions/QueueNotFoundException.cs

@@ -0,0 +1,21 @@
+using System;
+using GuardNet;
+
+namespace Promitor.Integrations.AzureStorage.Exceptions
+{
+    public class QueueNotFoundException : Exception
+    {
+        /// <summary>
+        ///     Constructor
+        /// </summary>
+        /// <param name="queueName">Name of the queue that was not found</param>
+        public QueueNotFoundException(string queueName) : base($"Azure Storage Queue '{queueName}' was not found")
+        {
+            Guard.NotNullOrEmpty(queueName, nameof(queueName));
+
+            QueueName = queueName;
+        }
+
+        public string QueueName { get; }
+    }
+}

src/Promitor.Integrations.AzureStorage/Promitor.Integrations.AzureStorage.csproj

@@ -5,6 +5,7 @@
     </PropertyGroup>
 
     <ItemGroup>
+      <PackageReference Include="Guard.Net" Version="1.2.0" />
       <PackageReference Include="Microsoft.Azure.Storage.Queue" Version="9.4.2" />
       <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="2.2.0" />
     </ItemGroup>

src/Promitor.Scraper.Host/Scheduling/MetricScrapingJob.cs

@@ -59,6 +59,7 @@ public async Task ExecuteAsync(CancellationToken cancellationToken)
                     var scrapingTask = ScrapeMetric(scrapeConfiguration.AzureMetadata, scrapeConfiguration.MetricDefaults, metricDefinition);
                     scrapingTasks.Add(scrapingTask);
                 }
+
                 await Task.WhenAll(scrapingTasks);
             }
             catch (Exception exception)

src/Promitor.Scraper.Host/Validation/MetricDefinitions/ResourceTypes/StorageQueueMetricValidator.cs

@@ -22,7 +22,7 @@ public List<string> Validate(StorageQueueMetricDefinition metricDefinition)
 
             if (string.IsNullOrWhiteSpace(metricDefinition.SasToken))
             {
-                errorMessages.Add("No Azure Storage Queue SAS Token is configured");
+                errorMessages.Add("No Azure Storage SAS Token is configured");
             }
 
             if (metricDefinition.AzureMetricConfiguration.MetricName != "MessageCount")