[pack] Making bundles default, optimizing start up code path (#5254)

Author: soninaren

src/WebJobs.Script.WebHost/Resources/Functions/host.json

@@ -1,3 +1,7 @@
 {
-    "version": "2.0"
+  "version": "2.0",
+  "extensionBundle": {
+    "id": "Microsoft.Azure.Functions.ExtensionBundle",
+    "version": "[1.*, 2.0.0)"
+  }
 }

src/WebJobs.Script/Config/HostJsonFileConfigurationSource.cs

@@ -204,7 +204,7 @@ internal JObject LoadHostConfig(string configFilePath)
 
             private JObject GetDefaultHostConfigObject()
             {
-                var hostJsonJObj = JObject.Parse("{'version': '2.0'}");
+                var hostJsonJObj = JObject.Parse("{'version': '2.0', 'extensionBundle': { 'id': 'Microsoft.Azure.Functions.ExtensionBundle', 'version': '[1.*, 2.0.0)'}}");
                 if (string.Equals(_configurationSource.Environment.GetEnvironmentVariable(RpcWorkerConstants.FunctionWorkerRuntimeSettingName), "powershell", StringComparison.InvariantCultureIgnoreCase)
                     && !_configurationSource.Environment.IsFileSystemReadOnly())
                 {

src/WebJobs.Script/DependencyInjection/ScriptStartupTypeLocator.cs

@@ -62,8 +62,23 @@ public Type[] GetStartupTypes()
         public async Task<IEnumerable<Type>> GetExtensionsStartupTypesAsync()
         {
             string binPath;
-            if (_extensionBundleManager.IsExtensionBundleConfigured())
+            var functionMetadataCollection = _functionMetadataProvider.GetFunctionMetadata(forceRefresh: true);
+            HashSet<string> bindingsSet = null;
+            var bundleConfigured = _extensionBundleManager.IsExtensionBundleConfigured();
+
+            if (bundleConfigured)
             {
+                bindingsSet = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+                // Generate a Hashset of all the binding types used in the function app
+                foreach (var functionMetadata in functionMetadataCollection)
+                {
+                    foreach (var binding in functionMetadata.Bindings)
+                    {
+                        bindingsSet.Add(binding.Type);
+                    }
+                }
+
                 string extensionBundlePath = await _extensionBundleManager.GetExtensionBundlePath();
                 if (string.IsNullOrEmpty(extensionBundlePath))
                 {
@@ -85,14 +100,11 @@ public async Task<IEnumerable<Type>> GetExtensionsStartupTypesAsync()
 
             var startupTypes = new List<Type>();
 
-            var functionBindings = _functionMetadataProvider.GetFunctionMetadata(forceRefresh: true).SelectMany(f => f.Bindings.Select(b => b.Type));
-
-            var bundleConfigured = _extensionBundleManager.IsExtensionBundleConfigured();
             foreach (var extensionItem in extensionItems)
             {
                 if (!bundleConfigured
                     || extensionItem.Bindings.Count == 0
-                    || extensionItem.Bindings.Intersect(functionBindings, StringComparer.OrdinalIgnoreCase).Any())
+                    || extensionItem.Bindings.Intersect(bindingsSet, StringComparer.OrdinalIgnoreCase).Any())
                 {
                     string startupExtensionName = extensionItem.Name ?? extensionItem.TypeName;
                     _logger.ScriptStartUpLoadingStartUpExtension(startupExtensionName);

test/WebJobs.Script.Tests/Configuration/HostJsonFileConfigurationSourceTests.cs

@@ -18,7 +18,7 @@ namespace Microsoft.Azure.WebJobs.Script.Tests.Configuration
 {
     public class HostJsonFileConfigurationSourceTests
     {
-        private readonly string _defaultHostJson = "{\r\n  \"version\": \"2.0\"\r\n}";
+        private readonly string _defaultHostJson = "{\r\n  \"version\": \"2.0\",\r\n  \"extensionBundle\": {\r\n    \"id\": \"Microsoft.Azure.Functions.ExtensionBundle\",\r\n    \"version\": \"[1.*, 2.0.0)\"\r\n  }\r\n}";
         private readonly ScriptApplicationHostOptions _options;
         private readonly string _hostJsonFile;
         private readonly TestLoggerProvider _loggerProvider = new TestLoggerProvider();