[Cherrypick] [pack] Sourcing configuration from WebHost and Active JobHost for Storage operations (#7506)

Francisco-Gamino · web-flow · commit 3499952c7f6a · 2021-06-30T08:55:20.000-07:00
diff --git a/src/WebJobs.Script.WebHost/Security/KeyManagement/DefaultSecretManagerProvider.cs b/src/WebJobs.Script.WebHost/Security/KeyManagement/DefaultSecretManagerProvider.cs
@@ -61,7 +61,6 @@ public DefaultSecretManagerProvider(IOptionsMonitor<ScriptApplicationHostOptions
         internal ISecretsRepository CreateSecretsRepository()
         {
             string secretStorageType = Environment.GetEnvironmentVariable(EnvironmentSettingNames.AzureWebJobsSecretStorageType);
-            var storageConnection = _configuration.GetWebJobsConnectionStringSection(ConnectionStringNames.Storage);
             string secretStorageSas = _environment.GetEnvironmentVariable(EnvironmentSettingNames.AzureWebJobsSecretStorageSas);
             if (secretStorageType != null && secretStorageType.Equals(FileStorage, StringComparison.OrdinalIgnoreCase))
             {
@@ -83,7 +82,7 @@ internal ISecretsRepository CreateSecretsRepository()
                 string siteSlotName = _environment.GetAzureWebsiteUniqueSlotName() ?? _hostIdProvider.GetHostIdAsync(CancellationToken.None).GetAwaiter().GetResult();
                 return new BlobStorageSasSecretsRepository(Path.Combine(_options.CurrentValue.SecretsPath, "Sentinels"), secretStorageSas, siteSlotName, _loggerFactory.CreateLogger<BlobStorageSasSecretsRepository>(), _environment, _azureStorageProvider);
             }
-            else if (storageConnection.Exists())
+            else if (_azureStorageProvider.ConnectionExists(ConnectionStringNames.Storage))
             {
                 string siteSlotName = _environment.GetAzureWebsiteUniqueSlotName() ?? _hostIdProvider.GetHostIdAsync(CancellationToken.None).GetAwaiter().GetResult();
                 return new BlobStorageSecretsRepository(Path.Combine(_options.CurrentValue.SecretsPath, "Sentinels"), ConnectionStringNames.Storage, siteSlotName, _loggerFactory.CreateLogger<BlobStorageSecretsRepository>(), _environment, _azureStorageProvider);
diff --git a/src/WebJobs.Script.WebHost/WebJobsScriptHostService.cs b/src/WebJobs.Script.WebHost/WebJobsScriptHostService.cs
@@ -95,6 +95,8 @@ public WebJobsScriptHostService(IOptionsMonitor<ScriptApplicationHostOptions> ap
 
         public event EventHandler HostInitializing;
 
+        public event EventHandler<ActiveHostChangedEventArgs> ActiveHostChanged;
+
         [Flags]
         private enum JobHostStartupMode
         {
@@ -118,7 +120,11 @@ private IHost ActiveHost
             set
             {
                 _logger?.ActiveHostChanging(GetHostInstanceId(_host), GetHostInstanceId(value));
+
+                var previousHost = _host;
                 _host = value;
+
+                OnActiveHostChanged(previousHost, _host);
             }
         }
 
@@ -530,6 +536,11 @@ private void OnHostInitializing(object sender, EventArgs e)
             HostInitializing?.Invoke(sender, e);
         }
 
+        private void OnActiveHostChanged(IHost previousHost, IHost newHost)
+        {
+            ActiveHostChanged?.Invoke(this, new ActiveHostChangedEventArgs(previousHost, _host));
+        }
+
         /// <summary>
         /// Called after the host has been fully initialized, but before it
         /// has been started.
diff --git a/src/WebJobs.Script/ActiveHostChangedEventArgs.cs b/src/WebJobs.Script/ActiveHostChangedEventArgs.cs
@@ -0,0 +1,21 @@
+﻿// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the MIT License. See License.txt in the project root for license information.
+
+using System;
+using Microsoft.Extensions.Hosting;
+
+namespace Microsoft.Azure.WebJobs.Script
+{
+    public sealed class ActiveHostChangedEventArgs : EventArgs
+    {
+        public ActiveHostChangedEventArgs(IHost previousHost, IHost newHost)
+        {
+            PreviousHost = previousHost;
+            NewHost = newHost;
+        }
+
+        public IHost NewHost { get; }
+
+        public IHost PreviousHost { get; }
+    }
+}
diff --git a/src/WebJobs.Script/Config/ActiveHostConfigurationSource.cs b/src/WebJobs.Script/Config/ActiveHostConfigurationSource.cs
@@ -0,0 +1,66 @@
+﻿// Copyright (c) .NET Foundation. 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 Microsoft.Extensions.Configuration;
+
+namespace Microsoft.Azure.WebJobs.Script.Configuration
+{
+    public class ActiveHostConfigurationSource : IConfigurationSource
+    {
+        private readonly IScriptHostManager _scriptHostManager;
+
+        public ActiveHostConfigurationSource(IScriptHostManager scriptHostManager)
+        {
+            _scriptHostManager = scriptHostManager;
+        }
+
+        public IConfigurationProvider Build(IConfigurationBuilder builder)
+        {
+            return new ActiveHostConfigurationProvider(_scriptHostManager);
+        }
+
+        private class ActiveHostConfigurationProvider : ConfigurationProvider, IDisposable
+        {
+            private readonly IScriptHostManager _scriptHostManager;
+            private IDisposable _changeTokenRegistration;
+
+            public ActiveHostConfigurationProvider(IScriptHostManager scriptHostManager)
+            {
+                _scriptHostManager = scriptHostManager ?? throw new ArgumentNullException(nameof(scriptHostManager));
+                scriptHostManager.ActiveHostChanged += HandleActiveHostChange;
+            }
+
+            public override void Load()
+            {
+                if ((_scriptHostManager as IServiceProvider)?.GetService(typeof(IConfiguration)) is IConfigurationRoot activeHostConfiguration)
+                {
+                    Data = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+                    foreach (var kvp in activeHostConfiguration.AsEnumerable())
+                    {
+                        if (!Data.ContainsKey(kvp.Key))
+                        {
+                            Data[kvp.Key] = kvp.Value;
+                        }
+                    }
+
+                    _changeTokenRegistration?.Dispose();
+                    _changeTokenRegistration = activeHostConfiguration.GetReloadToken().RegisterChangeCallback(_ => Load(), null);
+                    OnReload();
+                }
+            }
+
+            private void HandleActiveHostChange(object sender, ActiveHostChangedEventArgs e)
+            {
+                Load();
+            }
+
+            public void Dispose()
+            {
+                _changeTokenRegistration?.Dispose();
+                _scriptHostManager.ActiveHostChanged -= HandleActiveHostChange;
+            }
+        }
+    }
+}
diff --git a/src/WebJobs.Script/Host/IScriptHostManager.cs b/src/WebJobs.Script/Host/IScriptHostManager.cs
@@ -14,6 +14,11 @@ public interface IScriptHostManager
         /// </summary>
         event EventHandler HostInitializing;
 
+        /// <summary>
+        /// Evewnt raised when the active host managed by this instance changes.
+        /// </summary>
+        event EventHandler<ActiveHostChangedEventArgs> ActiveHostChanged;
+
         ScriptHostState State { get; }
 
         /// <summary>
diff --git a/src/WebJobs.Script/ScriptConstants.cs b/src/WebJobs.Script/ScriptConstants.cs
@@ -112,6 +112,7 @@ public static class ScriptConstants
         public const string FeatureFlagEnableEnhancedScopes = "EnableEnhancedScopes";
         public const string FeatureFlagDisableDevInDebug = "DisableDevModeInDebug";
         public const string FeatureFlagEnableDiagnosticEventLogging = "EnableDiagnosticEventLogging";
+        public const string FeatureFlagDisableMergedWebHostScriptHostConfiguration = "DisableMergedConfiguration";
 
         public const string AdminJwtValidAudienceFormat = "https://{0}.azurewebsites.net/azurefunctions";
         public const string AdminJwtValidIssuerFormat = "https://{0}.scm.azurewebsites.net";
diff --git a/src/WebJobs.Script/ScriptHostBuilderExtensions.cs b/src/WebJobs.Script/ScriptHostBuilderExtensions.cs
@@ -466,7 +466,6 @@ private static IDistributedLockManager GetBlobLockManager(IServiceProvider provi
             {
                 // If there is an error getting the container client,
                 // register an InMemoryDistributedLockManager.
-                // This signals a failed validation in connection configuration (i.e. could not create the storage client).
                 logger.LogDebug("Using InMemoryDistributedLockManager in Functions Host.");
                 return new InMemoryDistributedLockManager();
             }
diff --git a/src/WebJobs.Script/StorageProvider/AzureStorageProvider.cs b/src/WebJobs.Script/StorageProvider/AzureStorageProvider.cs
@@ -3,6 +3,9 @@
 
 using System;
 using Azure.Storage.Blobs;
+using Microsoft.Azure.WebJobs.Script.Config;
+using Microsoft.Azure.WebJobs.Script.Configuration;
+using Microsoft.Azure.WebJobs.Script.Extensions;
 using Microsoft.Azure.WebJobs.Script.StorageProvider;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Logging;
@@ -18,16 +21,39 @@ namespace Microsoft.Azure.WebJobs.Script
     internal class AzureStorageProvider : IAzureStorageProvider
     {
         private readonly BlobServiceClientProvider _blobServiceClientProvider;
-        private readonly IConfiguration _configuration;
-        private readonly ILogger _logger;
         private IOptionsMonitor<JobHostInternalStorageOptions> _storageOptions;
+        private IConfiguration _configuration;
+        private ILogger _logger;
 
-        public AzureStorageProvider(IConfiguration configuration, BlobServiceClientProvider blobServiceClientProvider, IOptionsMonitor<JobHostInternalStorageOptions> options, ILogger<AzureStorageProvider> logger)
+        public AzureStorageProvider(IScriptHostManager scriptHostManager, IConfiguration configuration, BlobServiceClientProvider blobServiceClientProvider, IOptionsMonitor<JobHostInternalStorageOptions> options, ILogger<AzureStorageProvider> logger)
         {
             _blobServiceClientProvider = blobServiceClientProvider;
-            _configuration = configuration;
             _storageOptions = options;
             _logger = logger;
+
+            if (FeatureFlags.IsEnabled(ScriptConstants.FeatureFlagDisableMergedWebHostScriptHostConfiguration))
+            {
+                _configuration = configuration;
+            }
+            else
+            {
+                _ = scriptHostManager ?? throw new ArgumentNullException(nameof(scriptHostManager));
+                _configuration = new ConfigurationBuilder()
+                    .AddConfiguration(configuration)
+                    .Add(new ActiveHostConfigurationSource(scriptHostManager))
+                    .Build();
+            }
+        }
+
+        /// <summary>
+        /// Checks if a BlobServiceClient can be created (indicates the specified connection can be parsed)
+        /// </summary>
+        /// <param name="connection">connection to use for the BlobServiceClient</param>
+        /// <returns>true if successful; false otherwise</returns>
+        public bool ConnectionExists(string connection)
+        {
+            var section = _configuration.GetWebJobsConnectionStringSection(connection);
+            return section != null && section.Exists();
         }
 
         /// <summary>
@@ -52,7 +78,7 @@ public virtual bool TryGetBlobServiceClientFromConnectionString(out BlobServiceC
         public virtual bool TryGetBlobServiceClientFromConnection(out BlobServiceClient client, string connection = null)
         {
             var connectionToUse = connection ?? ConnectionStringNames.Storage;
-            return _blobServiceClientProvider.TryGet(connectionToUse, out client);
+            return _blobServiceClientProvider.TryGet(connectionToUse, _configuration, out client);
         }
 
         public virtual BlobContainerClient GetBlobContainerClient()
diff --git a/src/WebJobs.Script/StorageProvider/BlobServiceClientProvider.cs b/src/WebJobs.Script/StorageProvider/BlobServiceClientProvider.cs
@@ -16,8 +16,8 @@ namespace Microsoft.Azure.WebJobs.Script.StorageProvider
     /// </summary>
     internal class BlobServiceClientProvider : StorageClientProvider<BlobServiceClient, BlobClientOptions>
     {
-        public BlobServiceClientProvider(IConfiguration configuration, AzureComponentFactory componentFactory, AzureEventSourceLogForwarder logForwarder, ILogger<BlobServiceClientProvider> logger)
-            : base(configuration, componentFactory, logForwarder, logger) { }
+        public BlobServiceClientProvider(AzureComponentFactory componentFactory, AzureEventSourceLogForwarder logForwarder, ILogger<BlobServiceClientProvider> logger)
+            : base(componentFactory, logForwarder, logger) { }
 
         /// <inheritdoc/>
         protected override string ServiceUriSubDomain
diff --git a/src/WebJobs.Script/StorageProvider/IAzureStorageProvider.cs b/src/WebJobs.Script/StorageProvider/IAzureStorageProvider.cs
@@ -2,6 +2,7 @@
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
 using Azure.Storage.Blobs;
+using Microsoft.Extensions.Configuration;
 
 namespace Microsoft.Azure.WebJobs.Script
 {
@@ -11,6 +12,8 @@ namespace Microsoft.Azure.WebJobs.Script
     /// </summary>
     public interface IAzureStorageProvider
     {
+        bool ConnectionExists(string connection);
+
         bool TryGetBlobServiceClientFromConnectionString(out BlobServiceClient client, string connectionString);
 
         bool TryGetBlobServiceClientFromConnection(out BlobServiceClient client, string connection);
diff --git a/src/WebJobs.Script/StorageProvider/StorageClientProvider.cs b/src/WebJobs.Script/StorageProvider/StorageClientProvider.cs
@@ -21,7 +21,6 @@ namespace Microsoft.Azure.WebJobs.Script.StorageProvider
     /// </summary>
     internal abstract class StorageClientProvider<TClient, TClientOptions> where TClientOptions : ClientOptions
     {
-        private readonly IConfiguration _configuration;
         private readonly AzureComponentFactory _componentFactory;
         private readonly AzureEventSourceLogForwarder _logForwarder;
         private readonly ILogger _logger;
@@ -32,9 +31,8 @@ internal abstract class StorageClientProvider<TClient, TClientOptions> where TCl
         /// <param name="configuration">The configuration to use when creating Client-specific objects. <see cref="IConfiguration"/></param>
         /// <param name="componentFactory">The Azure factory responsible for creating clients. <see cref="AzureComponentFactory"/></param>
         /// <param name="logForwarder">Log forwarder that forwards events to ILogger. <see cref="AzureEventSourceLogForwarder"/></param>
-        public StorageClientProvider(IConfiguration configuration, AzureComponentFactory componentFactory, AzureEventSourceLogForwarder logForwarder, ILogger<StorageClientProvider<TClient, TClientOptions>> logger)
+        public StorageClientProvider(AzureComponentFactory componentFactory, AzureEventSourceLogForwarder logForwarder, ILogger<StorageClientProvider<TClient, TClientOptions>> logger)
         {
-            _configuration = configuration;
             _componentFactory = componentFactory;
             _logForwarder = logForwarder;
             _logger = logger;
@@ -53,13 +51,14 @@ public StorageClientProvider(IConfiguration configuration, AzureComponentFactory
         /// Gets the storage client specified by <paramref name="name"/>
         /// </summary>
         /// <param name="name">Name of the connection to use</param>
+        /// <param name="configuration">Configuration to use</param>
         /// <param name="client">Client that was created if the connection was valid; otherwise, the default value for the type of <paramref name="client"/>.</param>
         /// <returns>true if the client could be created; false otherwise</returns>
-        public virtual bool TryGet(string name, out TClient client)
+        public virtual bool TryGet(string name, IConfiguration configuration, out TClient client)
         {
             try
             {
-                client = Get(name);
+                client = Get(name, configuration);
                 return true;
             }
             catch (Exception ex)
@@ -96,28 +95,30 @@ public virtual bool TryGetFromConnectionString(string connectionString, out TCli
         /// </summary>
         /// <param name="name">Name of the connection to use</param>
         /// <param name="resolver">A resolver to interpret the provided connection <paramref name="name"/>.</param>
+        /// <param name="configuration">Configuration to use</param>
         /// <returns>Client that was created.</returns>
-        public virtual TClient Get(string name, INameResolver resolver)
+        public virtual TClient Get(string name, INameResolver resolver, IConfiguration configuration)
         {
             var resolvedName = resolver.ResolveWholeString(name);
-            return this.Get(resolvedName);
+            return this.Get(resolvedName, configuration);
         }
 
         /// <summary>
         /// Gets the storage client specified by <paramref name="name"/>
         /// </summary>
         /// <param name="name">Name of the connection to use</param>
+        /// <param name="configuration">Configuration to use</param>
         /// <returns>Client that was created.</returns>
-        public virtual TClient Get(string name)
+        public virtual TClient Get(string name, IConfiguration configuration)
         {
             if (string.IsNullOrWhiteSpace(name))
             {
                 name = ConnectionStringNames.Storage; // default
             }
 
             // $$$ Where does validation happen?
-            IConfigurationSection connectionSection = _configuration.GetWebJobsConnectionStringSection(name);
-            if (!connectionSection.Exists())
+            IConfigurationSection connectionSection = configuration?.GetWebJobsConnectionStringSection(name);
+            if (connectionSection == null || !connectionSection.Exists())
             {
                 // Not found
                 throw new InvalidOperationException($"Storage account connection string '{IConfigurationExtensions.GetPrefixedConnectionStringName(name)}' does not exist. Make sure that it is a defined App Setting.");
@@ -148,7 +149,7 @@ protected virtual TClient CreateClient(IConfiguration configuration, TokenCreden
         /// <returns>Storage client</returns>
         public virtual TClient GetHost()
         {
-            return this.Get(null);
+            return this.Get(null, null);
         }
 
         /// <summary>
@@ -177,12 +178,12 @@ protected virtual bool TryGetServiceUri(IConfiguration configuration, out Uri se
 
                 string accountName;
                 string uriStr;
-                if ((accountName = configuration.GetValue<string>("accountName")) != null)
+                if ((accountName = configuration?.GetValue<string>("accountName")) != null)
                 {
                     serviceUri = FormatServiceUri(accountName);
                     return true;
                 }
-                else if ((uriStr = configuration.GetValue<string>(serviceUriConfig)) != null)
+                else if ((uriStr = configuration?.GetValue<string>(serviceUriConfig)) != null)
                 {
                     serviceUri = new Uri(uriStr);
                     return true;
diff --git a/test/WebJobs.Script.Tests.Integration/Host/SingletonTests/SingletonEndToEndTests.cs b/test/WebJobs.Script.Tests.Integration/Host/SingletonTests/SingletonEndToEndTests.cs
@@ -25,6 +25,7 @@
 using Newtonsoft.Json.Linq;
 using Xunit;
 using Microsoft.Azure.WebJobs.Host;
+using Microsoft.WebJobs.Script.Tests;
 
 namespace Microsoft.Azure.WebJobs.Script.Tests.Integration.Host.SingletonTests
 {
@@ -656,6 +657,7 @@ private IHost CreateTestJobHost<TProg>(int hostId, Action<IHostBuilder> extraCon
 
                     services.AddSingleton<IDistributedLockManager, BlobLeaseDistributedLockManager>();
                     services.AddAzureStorageProvider();
+                    TestHostBuilderExtensions.AddMockedSingleton<IScriptHostManager>(services);
                 });
 
             extraConfig?.Invoke(hostBuilder); // test hook gets final say to replace. 
diff --git a/test/WebJobs.Script.Tests.Integration/ScriptHostEndToEnd/FunctionGeneratorEndToEndTests.cs b/test/WebJobs.Script.Tests.Integration/ScriptHostEndToEnd/FunctionGeneratorEndToEndTests.cs
@@ -11,6 +11,7 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
+using Microsoft.WebJobs.Script.Tests;
 using Xunit;
 
 namespace Microsoft.Azure.WebJobs.Script.Tests
@@ -71,6 +72,7 @@ public async Task Generate_EndToEnd()
                     s.AddSingleton<ILoggerFactory>(new LoggerFactory());
 
                     s.AddAzureStorageProvider();
+                    TestHostBuilderExtensions.AddMockedSingleton<IScriptHostManager>(s);
                 });
 
             using (var host = builder.Build())
diff --git a/test/WebJobs.Script.Tests.Integration/Storage/AzureStorageProviderTests.cs b/test/WebJobs.Script.Tests.Integration/Storage/AzureStorageProviderTests.cs
diff --git a/test/WebJobs.Script.Tests.Integration/Storage/BlobServiceClientProviderTests.cs b/test/WebJobs.Script.Tests.Integration/Storage/BlobServiceClientProviderTests.cs
diff --git a/test/WebJobs.Script.Tests.Integration/WebHostEndToEnd/SpecializationE2ETests.cs b/test/WebJobs.Script.Tests.Integration/WebHostEndToEnd/SpecializationE2ETests.cs
diff --git a/test/WebJobs.Script.Tests.Shared/TestHelpers.cs b/test/WebJobs.Script.Tests.Shared/TestHelpers.cs
diff --git a/test/WebJobs.Script.Tests/Configuration/ActiveHostConfigurationSourceTests.cs b/test/WebJobs.Script.Tests/Configuration/ActiveHostConfigurationSourceTests.cs
diff --git a/test/WebJobs.Script.Tests/Managment/WebFunctionsManagerTests.cs b/test/WebJobs.Script.Tests/Managment/WebFunctionsManagerTests.cs

Original file line number	Diff line number	Diff line change
`@@ -61,7 +61,6 @@ public DefaultSecretManagerProvider(IOptionsMonitor<ScriptApplicationHostOptions`
`61`	`61`	`internal ISecretsRepository CreateSecretsRepository()`
`62`	`62`	`{`
`63`	`63`	`string secretStorageType = Environment.GetEnvironmentVariable(EnvironmentSettingNames.AzureWebJobsSecretStorageType);`
`64`		`- var storageConnection = _configuration.GetWebJobsConnectionStringSection(ConnectionStringNames.Storage);`
`65`	`64`	`string secretStorageSas = _environment.GetEnvironmentVariable(EnvironmentSettingNames.AzureWebJobsSecretStorageSas);`
`66`	`65`	`if (secretStorageType != null && secretStorageType.Equals(FileStorage, StringComparison.OrdinalIgnoreCase))`
`67`	`66`	`{`
`@@ -83,7 +82,7 @@ internal ISecretsRepository CreateSecretsRepository()`
`83`	`82`	`string siteSlotName = _environment.GetAzureWebsiteUniqueSlotName() ?? _hostIdProvider.GetHostIdAsync(CancellationToken.None).GetAwaiter().GetResult();`
`84`	`83`	`return new BlobStorageSasSecretsRepository(Path.Combine(_options.CurrentValue.SecretsPath, "Sentinels"), secretStorageSas, siteSlotName, _loggerFactory.CreateLogger<BlobStorageSasSecretsRepository>(), _environment, _azureStorageProvider);`
`85`	`84`	`}`
`86`		`- else if (storageConnection.Exists())`
	`85`	`+ else if (_azureStorageProvider.ConnectionExists(ConnectionStringNames.Storage))`
`87`	`86`	`{`
`88`	`87`	`string siteSlotName = _environment.GetAzureWebsiteUniqueSlotName() ?? _hostIdProvider.GetHostIdAsync(CancellationToken.None).GetAwaiter().GetResult();`
`89`	`88`	`return new BlobStorageSecretsRepository(Path.Combine(_options.CurrentValue.SecretsPath, "Sentinels"), ConnectionStringNames.Storage, siteSlotName, _loggerFactory.CreateLogger<BlobStorageSecretsRepository>(), _environment, _azureStorageProvider);`
Original file line number	Diff line number	Diff line change
`@@ -95,6 +95,8 @@ public WebJobsScriptHostService(IOptionsMonitor<ScriptApplicationHostOptions> ap`
`95`	`95`
`96`	`96`	`public event EventHandler HostInitializing;`
`97`	`97`
	`98`	`+ public event EventHandler<ActiveHostChangedEventArgs> ActiveHostChanged;`
	`99`	`+`
`98`	`100`	`[Flags]`
`99`	`101`	`private enum JobHostStartupMode`
`100`	`102`	`{`
`@@ -118,7 +120,11 @@ private IHost ActiveHost`
`118`	`120`	`set`
`119`	`121`	`{`
`120`	`122`	`_logger?.ActiveHostChanging(GetHostInstanceId(_host), GetHostInstanceId(value));`
	`123`	`+`
	`124`	`+ var previousHost = _host;`
`121`	`125`	`_host = value;`
	`126`	`+`
	`127`	`+ OnActiveHostChanged(previousHost, _host);`
`122`	`128`	`}`
`123`	`129`	`}`
`124`	`130`
`@@ -530,6 +536,11 @@ private void OnHostInitializing(object sender, EventArgs e)`
`530`	`536`	`HostInitializing?.Invoke(sender, e);`
`531`	`537`	`}`
`532`	`538`
	`539`	`+ private void OnActiveHostChanged(IHost previousHost, IHost newHost)`
	`540`	`+ {`
	`541`	`+ ActiveHostChanged?.Invoke(this, new ActiveHostChangedEventArgs(previousHost, _host));`
	`542`	`+ }`
	`543`	`+`
`533`	`544`	`/// <summary>`
`534`	`545`	`/// Called after the host has been fully initialized, but before it`
`535`	`546`	`/// has been started.`
Original file line number	Diff line number	Diff line change
`@@ -466,7 +466,6 @@ private static IDistributedLockManager GetBlobLockManager(IServiceProvider provi`
`466`	`466`	`{`
`467`	`467`	`// If there is an error getting the container client,`
`468`	`468`	`// register an InMemoryDistributedLockManager.`
`469`		`- // This signals a failed validation in connection configuration (i.e. could not create the storage client).`
`470`	`469`	`logger.LogDebug("Using InMemoryDistributedLockManager in Functions Host.");`
`471`	`470`	`return new InMemoryDistributedLockManager();`
`472`	`471`	`}`
Original file line number	Diff line number	Diff line change
`@@ -2,6 +2,7 @@`
`2`	`2`	`// Licensed under the MIT License. See License.txt in the project root for license information.`
`3`	`3`
`4`	`4`	`using Azure.Storage.Blobs;`
	`5`	`+using Microsoft.Extensions.Configuration;`
`5`	`6`
`6`	`7`	`namespace Microsoft.Azure.WebJobs.Script`
`7`	`8`	`{`
`@@ -11,6 +12,8 @@ namespace Microsoft.Azure.WebJobs.Script`
`11`	`12`	`/// </summary>`
`12`	`13`	`public interface IAzureStorageProvider`
`13`	`14`	`{`
	`15`	`+ bool ConnectionExists(string connection);`
	`16`	`+`
`14`	`17`	`bool TryGetBlobServiceClientFromConnectionString(out BlobServiceClient client, string connectionString);`
`15`	`18`
`16`	`19`	`bool TryGetBlobServiceClientFromConnection(out BlobServiceClient client, string connection);`