fix: Functions runtime: Revert to netcore3.0 for functions and make code more robust to functions variations

runtime/dotnet/azurefunctions/Microsoft.BotFramework.Composer.Functions.csproj

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>netcoreapp3.0</TargetFramework>
     <AzureFunctionsVersion>v3</AzureFunctionsVersion>
     <UserSecretsId>2eb1c70c-5cd2-4c08-8aab-df989c347067</UserSecretsId>
   </PropertyGroup>
@@ -12,7 +12,6 @@
     <CodeAnalysisRuleSet>..\core\Microsoft.BotFramework.Composer.Core.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.2" />
     <PackageReference Include="Microsoft.Azure.Functions.Extensions" Version="1.0.0" />
     <PackageReference Include="Microsoft.Bot.Builder" Version="4.10.5" />
     <PackageReference Include="Microsoft.Bot.Builder.AI.Luis" Version="4.10.5" />

runtime/dotnet/azurefunctions/Startup.cs

@@ -21,61 +21,42 @@
 using Microsoft.Bot.Connector.Authentication;
 using Microsoft.BotFramework.Composer.Core;
 using Microsoft.BotFramework.Composer.Core.Settings;
-
-//using Microsoft.BotFramework.Composer.CustomAction;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
+using System.Linq;
 using System.Reflection;
-using System.Text;
 
 [assembly: FunctionsStartup(typeof(Microsoft.BotFramework.Composer.Functions.Startup))]
 
 namespace Microsoft.BotFramework.Composer.Functions
 {
     public class Startup : FunctionsStartup
     {
-        private IConfigurationRoot BuildConfiguration(string rootDirectory)
-        {
-            var config = new ConfigurationBuilder();
-
-            // Config precedence 1: root app.settings
-            config.SetBasePath(rootDirectory);
-
-            // Config precedence 2: ComposerDialogs/settings settings which are injected by the composer publish
-            // Hard code the settings path to 'ComposerDialogs' for deployment
-
-            var configFile = Path.GetFullPath(Path.Combine(rootDirectory, @"ComposerDialogs/settings/appsettings.json"));
-            config.AddJsonFile(configFile, optional: true, reloadOnChange: true);
-
-            config.UseComposerSettings();
-
-            if (!Debugger.IsAttached)
-            {
-                config.AddUserSecrets<Startup>();
-            }
-
-            config.AddEnvironmentVariables();
-
-            return config.Build();
-        }
+        private const string AssetsDirectoryName = "ComposerDialogs";
+        private const string SettingsRelativePath = "settings/appsettings.json";
+        private const string WwwRoot = "wwwroot";
+        private const string DialogFileExtension = ".dialog";
+        private const string DefaultLanguageSetting = "DefaultLanguage";
+        private const string EnglishLocale = "en-us";
 
         public override void Configure(IFunctionsHostBuilder builder)
         {
-            var binDirectory = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
-            var rootDirectory = Directory.GetParent(binDirectory).FullName;
+            // Get assets directory.
+            var assetsDirectory = GetAssetsDirectory();
 
-            var rootConfiguration = BuildConfiguration(rootDirectory);
+            // Build configuration with assets.
+            var config = BuildConfiguration(assetsDirectory);
 
             var settings = new BotSettings();
-            rootConfiguration.Bind(settings);
+            config.Bind(settings);
 
             var services = builder.Services;
 
-            services.AddSingleton<IConfiguration>(rootConfiguration);
+            services.AddSingleton<IConfiguration>(config);
 
             services.AddLogging();
 
@@ -138,25 +119,24 @@ public override void Configure(IFunctionsHostBuilder builder)
             services.AddSingleton(conversationState);
 
             // Resource explorer to track declarative assets
-            var resourceExplorer = new ResourceExplorer().AddFolder(Path.Combine(rootDirectory, settings?.Bot ?? "."));
+            var resourceExplorer = new ResourceExplorer().AddFolder(assetsDirectory.FullName);
             services.AddSingleton(resourceExplorer);
 
             // Adapter
             services.AddSingleton<IBotFrameworkHttpAdapter, BotFrameworkHttpAdapter>(s =>
             {
                 // Retrieve required dependencies
-                //IConfiguration configuration = s.GetService<IConfiguration>();
                 IStorage storage = s.GetService<IStorage>();
                 UserState userState = s.GetService<UserState>();
                 ConversationState conversationState = s.GetService<ConversationState>();
                 TelemetryInitializerMiddleware telemetryInitializerMiddleware = s.GetService<TelemetryInitializerMiddleware>();
 
-                var adapter = new BotFrameworkHttpAdapter(new ConfigurationCredentialProvider(rootConfiguration));
+                var adapter = new BotFrameworkHttpAdapter(new ConfigurationCredentialProvider(config));
 
                 adapter
                   .UseStorage(storage)
                   .UseBotState(userState, conversationState)
-                  .Use(new RegisterClassMiddleware<IConfiguration>(rootConfiguration))
+                  .Use(new RegisterClassMiddleware<IConfiguration>(config))
                   .Use(telemetryInitializerMiddleware);
 
                 // Configure Middlewares
@@ -174,7 +154,7 @@ public override void Configure(IFunctionsHostBuilder builder)
                 return adapter;
             });
 
-            var defaultLocale = rootConfiguration.GetValue<string>("defaultLanguage") ?? "en-us";
+            var defaultLocale = config.GetValue<string>(DefaultLanguageSetting) ?? EnglishLocale;
 
             var removeRecipientMention = settings?.Feature?.RemoveRecipientMention ?? false;
 
@@ -187,7 +167,7 @@ public override void Configure(IFunctionsHostBuilder builder)
                     s.GetService<BotFrameworkClient>(),
                     s.GetService<SkillConversationIdFactoryBase>(),
                     s.GetService<IBotTelemetryClient>(),
-                    GetRootDialog(Path.Combine(rootDirectory, settings.Bot)),
+                    GetRootDialog(assetsDirectory.FullName),
                     defaultLocale,
                     removeRecipientMention));
         }
@@ -221,7 +201,7 @@ private string GetRootDialog(string folderPath)
             var dir = new DirectoryInfo(folderPath);
             foreach (var f in dir.GetFiles())
             {
-                if (f.Extension == ".dialog")
+                if (f.Extension == DialogFileExtension)
                 {
                     return f.Name;
                 }
@@ -234,5 +214,84 @@ private bool ConfigSectionValid(string val)
         {
             return !string.IsNullOrEmpty(val) && !val.StartsWith('<');
         }
+
+        private static DirectoryInfo GetAssetsDirectory()
+        {
+            // The directory structure in functions is as follows
+            // wwwroot
+            //   | bin
+            //   | ComposerDialogs
+            //   | messages
+            //   | ...
+            //
+            // However depending on the exact runtime environment and architecture (i.e. x64)
+            // there can be variations in the folder structure, for example having the binaries in
+            // an x64 subfolder within bin.
+            // To make this more flexible, we obtain the executing assembly location and navigate up
+            // the directory tree until wwwroot, and pick up the composer dialogs path from there,
+            // making this more robust.
+
+            // Obtain executing binary directory
+            var binDirectory = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
+
+            var parent = Directory.GetParent(binDirectory);
+
+            // Navigate folder structure upwards until we find the folder, reach wwwroot or there are no
+            // more parents to navigate
+            while (parent != null)
+            {
+                // For the current directory, check if there is a child directory named
+                // 'ComposerDialogs'
+                var children = parent.EnumerateDirectories(AssetsDirectoryName);
+
+                if (children.Any())
+                {
+                    // We found our assets directory!
+                    return children.First();
+                }
+                else
+                {
+                    // In functions, if we reached wwwroot, we cannot go further up. Fail the operation
+                    // so that an error is displayed in the functions telemetry and start page.
+                    if (parent.Name.Contains(WwwRoot))
+                    {
+                        throw new InvalidDataException($"Failed to start functions bot, could not find asset folder {AssetsDirectoryName} in path {parent.FullName}.");
+                    }
+                    else
+                    {
+                        // If we didn't reach wwwroot, keep going up.
+                        parent = parent.Parent;
+                    }
+                }
+            }
+
+            // We should never be here unless we failed to find the folder. Throw clear exception.
+            throw new InvalidDataException($"Failed to start functions bot, could not find asset folder {AssetsDirectoryName}.");
+        }
+
+
+        private static IConfigurationRoot BuildConfiguration(DirectoryInfo assetsDirectory)
+        {
+            var config = new ConfigurationBuilder();
+
+            // Config precedence 1: root app.settings in case users add it.
+            // Note that the function root (wwwroot) is one directory above the assets dir.
+            config.SetBasePath(assetsDirectory.Parent.FullName);
+
+            // Config precedence 2: ComposerDialogs/settings settings which are injected by the composer publish.
+            var configFile = Path.GetFullPath(Path.Combine(assetsDirectory.FullName, SettingsRelativePath));
+            config.AddJsonFile(configFile, optional: true, reloadOnChange: true);
+
+            config.UseComposerSettings();
+
+            if (!Debugger.IsAttached)
+            {
+                config.AddUserSecrets<Startup>();
+            }
+
+            config.AddEnvironmentVariables();
+
+            return config.Build();
+        }
     }
 }