Key per file (#28)

* Add KeyPerFile config builder, similar in concept/behavior as the KeyPerFile config source in .Net Core.

* Add Json.NET to sample app via nuget reference.

* Update Readme.md with KeyPerFile.

* Remove documentation about msbuild magic to grab UserSecretsId, as this is no longer a feature.

* Add KeyPerFile to sample app.

* Add example secrets.xml in Readme.md

* Update Readme language.

Author: StephenMolloy

MicrosoftConfigurationBuilders.sln

@@ -51,6 +51,11 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Environment", "src\Environm
 		{F382FBF8-146D-4968-A199-90D37F9EF9A7} = {F382FBF8-146D-4968-A199-90D37F9EF9A7}
 	EndProjectSection
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "KeyPerFile", "src\KeyPerFile\KeyPerFile.csproj", "{60C31149-44ED-4789-B5C3-AAA5D3B2FCF1}"
+	ProjectSection(ProjectDependencies) = postProject
+		{F382FBF8-146D-4968-A199-90D37F9EF9A7} = {F382FBF8-146D-4968-A199-90D37F9EF9A7}
+	EndProjectSection
+EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SampleWebApp", "samples\SampleWebApp\SampleWebApp.csproj", "{590892DD-F842-4E7C-9400-4C6451C16B1A}"
 EndProject
 Global
@@ -87,6 +92,10 @@ Global
 		{C6530E81-D8D8-47A8-912E-D2939F801835}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{C6530E81-D8D8-47A8-912E-D2939F801835}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{C6530E81-D8D8-47A8-912E-D2939F801835}.Release|Any CPU.Build.0 = Release|Any CPU
+		{60C31149-44ED-4789-B5C3-AAA5D3B2FCF1}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{60C31149-44ED-4789-B5C3-AAA5D3B2FCF1}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{60C31149-44ED-4789-B5C3-AAA5D3B2FCF1}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{60C31149-44ED-4789-B5C3-AAA5D3B2FCF1}.Release|Any CPU.Build.0 = Release|Any CPU
 		{590892DD-F842-4E7C-9400-4C6451C16B1A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{590892DD-F842-4E7C-9400-4C6451C16B1A}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{590892DD-F842-4E7C-9400-4C6451C16B1A}.Release|Any CPU.ActiveCfg = Release|Any CPU

README.md

@@ -87,13 +87,25 @@ builder, the json format for Core secrets is technically an implementation detai
 There are three additional configuration attributes for this config builder:
   * `userSecretsId` - This is the preferred method for identifying an xml secrets file. It works similar to .Net Core, which uses a 'UserSecretsId' project
   property to store this identifier. (The string does not have to be a Guid. Just unique. The VS "Manage User Secrets" experience produces a Guid.) With this
-  attribute, the `UserSecretsConfigBuilder` will look in a well-known local location for a secrets file belonging to this identifier. In MSBuild environments,
-  the value of this attribute will be replaced with the project property $(UserSecretsId) in the output directory iff the initial value is '${UserSecretsId}'.
-  One of this attribute or the 'userSecretsFile' attribute is required.
+  attribute, the `UserSecretsConfigBuilder` will look in a well-known local location (%APPDATA%\Microsoft\UserSecrets\<userSecretsId>\secrets.xml in
+  Windows environments) for a secrets file belonging to this identifier.
   * `userSecretsFile` - An optional attribute specifying the file containing the secrets. The '~' character can be used at the start to reference the app root.
   One of this attribute or the 'userSecretsId' attribute is required. If both are specified, 'userSecretsFile' takes precedence.
   * `optional` - A simple boolean to avoid throwing exceptions if the secrets file cannot be found. The default is `true`.
 
+The next Visual Studio update will include "Manage User Secrets..." support for WebForms projects. When using this feature, Visual Studio will create an
+empty secrets file outside of the solution folder and allow editing the raw content to add/remove secrets. This is similar to the .Net Core experience,
+and currently exposes the format of the file - which as mentioned above - should be considered an implementation detail. A non-empty secrets file would look like this:
+
+```xml
+<?xml version="1.0" encoding="utf-8" ?>
+<root>
+  <secrets ver="1.0">
+    <secret name="secretFoo" value="valueBar" />
+  </secrets>
+</root>
+```
+
 ### AzureKeyVaultConfigBuilder
 ```xml
 <add name="AzureKeyVault"
@@ -117,6 +129,26 @@ up connection information from the execution environment if possible, but you ca
   this attribute to 'false', and secrets will be retrieved one at a time. This could also be useful if the vault allows "Get" access but not
   "List" access. (NOTE: Disabling preload is incompatible with Greedy mode.)
 
+### KeyPerFileConfigBuilder
+```xml
+<add name="KeyPerFile"
+    [mode|prefix|stripPrefix|tokenPattern]
+	(directoryPath="PathToSourceDirectory")
+    [ignorePrefix="ignore."]
+    [keyDelimiter=":"]
+    [optional="false"]
+    type="Microsoft.Configuration.ConfigurationBuilders.KeyPerFileConfigBuilder, Microsoft.Configuration.ConfigurationBuilders.KeyPerFile" />
+```
+This is a simple config builder that uses a directory's files as a source of values. A file's name is the key, and the contents are the value. This
+config builder can be useful when running in an orchestrated container environment, as systems like Docker Swarm and Kubernetes provide 'secrets' to
+their orchestrated windows containers in this key-per-file manner.
+  * `directoryPath` - This is a required attribute. It specifies a path to the source directory to look in for values. Docker for Windows secrets
+  are stored in the 'C:\ProgramData\Docker\secrets' directory by default.
+  * `ignorePrefix` - Files that start with this prefix will be excluded. Defaults to "ignore.".
+  * `keyDelimiter` - If specified, the config builder will traverse multiple levels of the directory, building key names up with this delimeter. If
+  this value is left `null` however, the config builder only looks at the top-level of the directory. `null` is the default.
+  * `optional` - Specifies whether the config builder should cause errors if the source directory doesn't exist. The default is `false`.
+
 ### SimpleJsonConfigBuilder
 ```xml
 <add name="SimpleJson"

samples/KeyPerFileSampleRoot/SecretFromFile1

@@ -0,0 +1 @@
+I might have been put here by a container orchestrator.

samples/KeyPerFileSampleRoot/SecretFromFile2

@@ -0,0 +1 @@
+I am definitely just a test secret.

samples/KeyPerFileSampleRoot/SubFeature/FeatureSecretA

@@ -0,0 +1 @@
+This might be a subfeature setting.

samples/KeyPerFileSampleRoot/ignore.SecretFromFile3

@@ -0,0 +1 @@
+This one should be ignored.

samples/SampleWebApp/SampleWebApp.csproj

@@ -48,6 +48,9 @@
       <HintPath>..\..\packages\Microsoft.CodeDom.Providers.DotNetCompilerPlatform.1.0.8\lib\net45\Microsoft.CodeDom.Providers.DotNetCompilerPlatform.dll</HintPath>
     </Reference>
     <Reference Include="Microsoft.CSharp" />
+    <Reference Include="Newtonsoft.Json, Version=11.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Newtonsoft.Json.11.0.1\lib\net45\Newtonsoft.Json.dll</HintPath>
+    </Reference>
     <Reference Include="System.Web.DynamicData" />
     <Reference Include="System.Web.Entity" />
     <Reference Include="System.Web.ApplicationServices" />
@@ -78,16 +81,14 @@
   <ItemGroup>
     <Content Include="App_Data\secrets.xml" />
     <Content Include="default.aspx" />
-    <Content Include="Web.config" />
+    <Content Include="Web.config">
+      <SubType>Designer</SubType>
+    </Content>
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="..\..\src\Azure\Azure.csproj">
-      <Project>{345c5437-4990-45dc-be34-6e37aa05d8d2}</Project>
-      <Name>Azure</Name>
-    </ProjectReference>
     <ProjectReference Include="..\..\src\Base\Base.csproj">
       <Project>{f382fbf8-146d-4968-a199-90d37f9ef9a7}</Project>
       <Name>Base</Name>
@@ -100,6 +101,10 @@
       <Project>{84e0ce5d-4af2-414f-a940-22b3f93fc727}</Project>
       <Name>Json</Name>
     </ProjectReference>
+    <ProjectReference Include="..\..\src\KeyPerFile\KeyPerFile.csproj">
+      <Project>{60c31149-44ed-4789-b5c3-aaa5d3b2fcf1}</Project>
+      <Name>KeyPerFile</Name>
+    </ProjectReference>
     <ProjectReference Include="..\..\src\UserSecrets\UserSecrets.csproj">
       <Project>{c60d6cbb-d513-4692-81a6-0be5d45e4702}</Project>
       <Name>UserSecrets</Name>
@@ -116,7 +121,7 @@
     <VisualStudio>
       <FlavorProperties GUID="{349c5851-65df-11da-9384-00065b846f21}">
         <WebProjectProperties>
-          <UseIIS>True</UseIIS>
+          <UseIIS>False</UseIIS>
           <AutoAssignPort>True</AutoAssignPort>
           <DevelopmentServerPort>58254</DevelopmentServerPort>
           <DevelopmentServerVPath>/</DevelopmentServerVPath>

samples/SampleWebApp/Web.config

@@ -14,10 +14,11 @@
       <!-- <add name="Environment" mode="Expand" type="Microsoft.Configuration.ConfigurationBuilders.EnvironmentConfigBuilder, Microsoft.Configuration.ConfigurationBuilders.Environment, Version=1.0.0.0, Culture=neutral"/> -->
       <add name="Secrets" userSecretsFile="~/App_Data/secrets.xml" mode="Greedy" type="Microsoft.Configuration.ConfigurationBuilders.UserSecretsConfigBuilder, Microsoft.Configuration.ConfigurationBuilders.UserSecrets, Version=1.0.0.0, Culture=neutral" />
       <add name="SimpleJson" jsonFile="~/App_Data/settings.json" ignoreMissingFile="true" type="Microsoft.Configuration.ConfigurationBuilders.SimpleJsonConfigBuilder, Microsoft.Configuration.ConfigurationBuilders.Json, Version=1.0.0.0, Culture=neutral" />
+      <add name="KeyPerFile" directoryPath="~/../KeyPerFileSampleRoot" mode="Greedy" keyDelimiter="--" type="Microsoft.Configuration.ConfigurationBuilders.KeyPerFileConfigBuilder, Microsoft.Configuration.ConfigurationBuilders.KeyPerFile, Version=1.0.0.0, Culture=neutral" />
     </builders>
   </configBuilders>
 
-  <appSettings configBuilders="Environment,SimpleJson,Secrets">
+  <appSettings configBuilders="Environment,SimpleJson,Secrets,KeyPerFile">
     <add key="WINDIR" value="Will be replaced by 'Environment' in Strict and Greedy modes." />
     <add key="SYSTEMDRIVE" value="Will initally be replaced by 'Environment' in Strict and Greedy modes... but then superceded by 'Secrets' in the same modes." />
     <add key="Value_Replaced_By_Environment_In_Expand_Mode" value="${WINDIR}" />

samples/SampleWebApp/packages.config

@@ -2,4 +2,5 @@
 <packages>
   <package id="Microsoft.CodeDom.Providers.DotNetCompilerPlatform" version="1.0.8" targetFramework="net471" />
   <package id="Microsoft.Net.Compilers" version="2.8.0" targetFramework="net471" developmentDependency="true" />
+  <package id="Newtonsoft.Json" version="11.0.1" targetFramework="net471" />
 </packages>

src/Base/KeyValueConfigBuilder.cs

@@ -251,6 +251,8 @@ private string TrimPrefix(string fullString)
 
         private string GetValueInternal(string key)
         {
+            if (String.IsNullOrEmpty(key)) { return null; }
+
             try
             {
                 return GetValue(key);