Preview3 (#10)

* Fix potential deadlock with Azure from ASP.Net when not preloading secret names.

* Remove -preview dependencies and rev to 'preview3'

Author: StephenMolloy

README.md

@@ -101,8 +101,8 @@ There are three additional configuration attributes for this config builder:
     (vaultName="MyVaultName" |
      uri="https://MyVaultName.vault.azure.net")
     [connectionString="connection string"]
-	[version="secrets version"]
-	[preloadSecretNames="true"]
+    [version="secrets version"]
+    [preloadSecretNames="true"]
     type="Microsoft.Configuration.ConfigurationBuilders.AzureKeyVaultConfigBuilder, Microsoft.Configuration.ConfigurationBuilders.Azure" />
 ```
 If your secrets are kept in Azure Key Vault, then this config builder is for you. There are three additional attributes for this config builder. The `vaultName` is
@@ -184,7 +184,7 @@ public class CustomConfigBuilder : KeyValueConfigBuilder
 Information on contributing to this repo is in the [Contributing Guide](CONTRIBUTING.md).
 
 ## Blog Posts
-[Announcing .NET 4.7.1 Tools for the Cloud](https://blogs.msdn.microsoft.com/webdev/2017/11/17/announcing-net-4-7-1-tools-for-the-cloud/)
-[.Net Framework 4.7.1 ASP.NET and Configuration features](https://blogs.msdn.microsoft.com/dotnet/2017/09/13/net-framework-4-7-1-asp-net-and-configuration-features/)
+[Announcing .NET 4.7.1 Tools for the Cloud](https://blogs.msdn.microsoft.com/webdev/2017/11/17/announcing-net-4-7-1-tools-for-the-cloud/)  
+[.Net Framework 4.7.1 ASP.NET and Configuration features](https://blogs.msdn.microsoft.com/dotnet/2017/09/13/net-framework-4-7-1-asp-net-and-configuration-features/)  
 [Modern Configuration for ASP.NET 4.7.1 with ConfigurationBuilders](http://jeffreyfritz.com/2017/11/modern-configuration-for-asp-net-4-7-1-with-configurationbuilders/)  
-[Service-to-service authentication to Azure Key Vault using .NET](https://docs.microsoft.com/en-us/azure/key-vault/service-to-service-authentication#connection-string-support)
+[Service-to-service authentication to Azure Key Vault using .NET](https://docs.microsoft.com/en-us/azure/key-vault/service-to-service-authentication#connection-string-support)  

src/Azure/Azure.csproj

@@ -37,13 +37,13 @@
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="Microsoft.Azure.KeyVault, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
-      <HintPath>..\..\packages\Microsoft.Azure.KeyVault.2.4.0-preview\lib\net452\Microsoft.Azure.KeyVault.dll</HintPath>
+      <HintPath>..\..\packages\Microsoft.Azure.KeyVault.2.3.2\lib\net452\Microsoft.Azure.KeyVault.dll</HintPath>
     </Reference>
     <Reference Include="Microsoft.Azure.KeyVault.WebKey, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
-      <HintPath>..\..\packages\Microsoft.Azure.KeyVault.WebKey.2.1.0-preview\lib\net452\Microsoft.Azure.KeyVault.WebKey.dll</HintPath>
+      <HintPath>..\..\packages\Microsoft.Azure.KeyVault.WebKey.2.0.7\lib\net452\Microsoft.Azure.KeyVault.WebKey.dll</HintPath>
     </Reference>
     <Reference Include="Microsoft.Azure.Services.AppAuthentication, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
-      <HintPath>..\..\packages\Microsoft.Azure.Services.AppAuthentication.1.1.0-preview\lib\net452\Microsoft.Azure.Services.AppAuthentication.dll</HintPath>
+      <HintPath>..\..\packages\Microsoft.Azure.Services.AppAuthentication.1.0.0\lib\net452\Microsoft.Azure.Services.AppAuthentication.dll</HintPath>
     </Reference>
     <Reference Include="Microsoft.IdentityModel.Clients.ActiveDirectory, Version=3.19.2.6005, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
       <HintPath>..\..\packages\Microsoft.IdentityModel.Clients.ActiveDirectory.3.19.2\lib\net45\Microsoft.IdentityModel.Clients.ActiveDirectory.dll</HintPath>
@@ -79,11 +79,9 @@
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory),MicrosoftConfigurationBuilders.sln))\tools\cleanup.targets" />
-  <Import Project="..\..\packages\Microsoft.Azure.Services.AppAuthentication.1.1.0-preview\build\Microsoft.Azure.Services.AppAuthentication.targets" Condition="Exists('..\..\packages\Microsoft.Azure.Services.AppAuthentication.1.1.0-preview\build\Microsoft.Azure.Services.AppAuthentication.targets')" />
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
     <PropertyGroup>
       <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
     </PropertyGroup>
-    <Error Condition="!Exists('..\..\packages\Microsoft.Azure.Services.AppAuthentication.1.1.0-preview\build\Microsoft.Azure.Services.AppAuthentication.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\Microsoft.Azure.Services.AppAuthentication.1.1.0-preview\build\Microsoft.Azure.Services.AppAuthentication.targets'))" />
   </Target>
 </Project>

src/Azure/AzureKeyVaultConfigBuilder.cs

@@ -68,7 +68,10 @@ public override void Initialize(string name, NameValueCollection config)
         public override string GetValue(string key)
         {
             // Azure Key Vault keys are case-insensitive, so this should be fine.
-            return GetValueAsync(key).Result;
+            // Also, this is a synchronous method. And in single-threaded contexts like ASP.Net
+            // it can be bad/dangerous to block on async calls. So lets work some TPL voodoo
+            // to avoid potential deadlocks.
+            return Task.Run(async () => { return await GetValueAsync(key); }).Result;
         }
 
         public override ICollection<KeyValuePair<string, string>> GetAllValues(string prefix)
@@ -94,14 +97,17 @@ private async Task<string> GetValueAsync(string key)
         {
             if (!_preload || _allKeys.Contains(key, StringComparer.OrdinalIgnoreCase))
             {
-                if (!String.IsNullOrWhiteSpace(_version))
+                try
                 {
-                    var versionedSecret = await _kvClient.GetSecretAsync(_uri, key, _version);
-                    return versionedSecret?.Value;
-                }
+                    if (!String.IsNullOrWhiteSpace(_version))
+                    {
+                        var versionedSecret = await _kvClient.GetSecretAsync(_uri, key, _version);
+                        return versionedSecret?.Value;
+                    }
 
-                var secret = await _kvClient.GetSecretAsync(_uri, key);
-                return secret?.Value;
+                    var secret = await _kvClient.GetSecretAsync(_uri, key);
+                    return secret?.Value;
+                } catch { }
             }
 
             return null;

src/Azure/packages.config

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="Microsoft.Azure.KeyVault" version="2.4.0-preview" targetFramework="net471" />
-  <package id="Microsoft.Azure.KeyVault.WebKey" version="2.1.0-preview" targetFramework="net471" />
-  <package id="Microsoft.Azure.Services.AppAuthentication" version="1.1.0-preview" targetFramework="net471" />
+  <package id="Microsoft.Azure.KeyVault" version="2.3.2" targetFramework="net471" />
+  <package id="Microsoft.Azure.KeyVault.WebKey" version="2.0.7" targetFramework="net471" />
+  <package id="Microsoft.Azure.Services.AppAuthentication" version="1.0" targetFramework="net471" />
   <package id="Microsoft.IdentityModel.Clients.ActiveDirectory" version="3.19.2" targetFramework="net471" />
   <package id="Microsoft.Rest.ClientRuntime" version="2.3.10" targetFramework="net471" />
   <package id="Microsoft.Rest.ClientRuntime.Azure" version="3.3.10" targetFramework="net471" />

tools/MicrosoftConfigurationBuilders.settings.targets

@@ -7,7 +7,7 @@
   <!-- Configurable properties-->
 
   <PropertyGroup>
-    <BuildQuality Condition="'$(BuildQuality)' == ''">preview2</BuildQuality>
+    <BuildQuality Condition="'$(BuildQuality)' == ''">preview3</BuildQuality>
     <VersionStartYear>2016</VersionStartYear>
     <VersionMajor>1</VersionMajor>
     <VersionMinor>0</VersionMinor>
@@ -16,7 +16,7 @@
   </PropertyGroup>
 
   <PropertyGroup Label="NuGet package dependencies">
-    <MicrosoftConfigurationBuildersNuGetPackageVersion>1.0.0-preview2</MicrosoftConfigurationBuildersNuGetPackageVersion>
+    <MicrosoftConfigurationBuildersNuGetPackageVersion>1.0.0-preview3</MicrosoftConfigurationBuildersNuGetPackageVersion>
   </PropertyGroup>
 
   <!-- Default properties -->