Add machine ID and exception logging (#202)

* Add machine ID

* Add exception tracking

Author: Charles-Gagnon

src/Telemetry/Telemetry.cs

@@ -186,11 +186,12 @@ private void InitializeTelemetry(string productVersion)
                 this._client.Context.Session.Id = CurrentSessionId;
                 this._client.Context.Device.OperatingSystem = RuntimeInformation.OSDescription;
 
-                this._commonProperties = new TelemetryCommonProperties(productVersion).GetTelemetryCommonProperties();
+                this._commonProperties = new TelemetryCommonProperties(productVersion, this._client).GetTelemetryCommonProperties();
                 this._commonMeasurements = new Dictionary<string, double>();
             }
             catch (Exception e)
             {
+                this._client.TrackException(e);
                 this._client = null;
                 // we don't want to fail the tool if telemetry fails.
                 Debug.Fail(e.ToString());

src/Telemetry/TelemetryCommonProperties.cs

@@ -1,32 +1,48 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Runtime.InteropServices;
+using Microsoft.ApplicationInsights;
 
 namespace Microsoft.Azure.WebJobs.Extensions.Sql.Telemetry
 {
     public class TelemetryCommonProperties
     {
         private readonly string _productVersion;
 
-        public TelemetryCommonProperties(
-            string productVersion)
+        public TelemetryCommonProperties(string productVersion, TelemetryClient telemetryClient)
         {
             this._productVersion = productVersion;
+            this._userLevelCacheWriter = new UserLevelCacheWriter(telemetryClient);
         }
 
+        private readonly UserLevelCacheWriter _userLevelCacheWriter;
+
         private const string OSVersion = "OSVersion";
         private const string ProductVersion = "ProductVersion";
+        private const string MachineId = "MachineId";
 
         public Dictionary<string, string> GetTelemetryCommonProperties()
         {
             return new Dictionary<string, string>
             {
                 {OSVersion, RuntimeInformation.OSDescription},
-                {ProductVersion, this._productVersion}
+                {ProductVersion, this._productVersion},
+                {MachineId, this.GetMachineId()},
             };
         }
+
+        private string GetMachineId()
+        {
+            return this._userLevelCacheWriter.RunWithCache(MachineId, () =>
+            {
+                // For now just use random GUID. Typically hashed MAC address is used but that's not
+                // something we need currently - a GUID per user is sufficient.
+                return Guid.NewGuid().ToString();
+            });
+        }
     }
 }
 

src/Telemetry/UserLevelCacheWriter.cs

@@ -0,0 +1,61 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See License.txt in the project root for license information.
+
+using System;
+using System.IO;
+using Microsoft.ApplicationInsights;
+
+namespace Microsoft.Azure.WebJobs.Extensions.Sql.Telemetry
+{
+    public sealed class UserLevelCacheWriter
+    {
+        private const string AzureFunctionsSqlBindingsProfileDirectoryName = ".azurefunctions-sqlbindings";
+        private readonly string _azureFunctionsSqlBindingsTryUserProfileFolderPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), AzureFunctionsSqlBindingsProfileDirectoryName);
+        private readonly TelemetryClient _telemetryClient;
+
+        public UserLevelCacheWriter(TelemetryClient telemetryClient)
+        {
+            this._telemetryClient = telemetryClient;
+        }
+
+        public string RunWithCache(string cacheKey, Func<string> getValueToCache)
+        {
+            string cacheFilepath = this.GetCacheFilePath(cacheKey);
+            try
+            {
+                if (!File.Exists(cacheFilepath))
+                {
+                    if (!Directory.Exists(this._azureFunctionsSqlBindingsTryUserProfileFolderPath))
+                    {
+                        Directory.CreateDirectory(this._azureFunctionsSqlBindingsTryUserProfileFolderPath);
+                    }
+
+                    string runResult = getValueToCache();
+
+                    File.WriteAllText(cacheFilepath, runResult);
+                    return runResult;
+                }
+                else
+                {
+                    return File.ReadAllText(cacheFilepath);
+                }
+            }
+            catch (Exception ex)
+            {
+                if (ex is UnauthorizedAccessException
+                    || ex is PathTooLongException
+                    || ex is IOException)
+                {
+                    this._telemetryClient.TrackException(ex);
+                    return getValueToCache();
+                }
+
+                throw;
+            }
+        }
+        private string GetCacheFilePath(string cacheKey)
+        {
+            return Path.Combine(this._azureFunctionsSqlBindingsTryUserProfileFolderPath, $"{cacheKey}.azureFunctionsSqlBindingsTryUserLevelCache");
+        }
+    }
+}