Refactor OpenAI configuration to use parameters

Author: eerhardt

src/eShop.AppHost/Extensions.cs

@@ -1,11 +1,18 @@
 using Aspire.Hosting.Lifecycle;
 using Aspire.Hosting.Yarp;
 using Aspire.Hosting.Yarp.Transforms;
-using Microsoft.Extensions.Configuration;
 using Yarp.ReverseProxy.Configuration;
 
 namespace eShop.AppHost;
 
+internal enum OpenAITarget
+{
+    OpenAI,
+    AzureOpenAI,
+    AzureOpenAIExisting,
+    AzureOpenAIExistingWithKey
+}
+
 internal static class Extensions
 {
     /// <summary>
@@ -38,7 +45,8 @@ public Task BeforeStartAsync(DistributedApplicationModel appModel, CancellationT
     /// </summary>
     public static IDistributedApplicationBuilder AddOpenAI(this IDistributedApplicationBuilder builder,
         IResourceBuilder<ProjectResource> catalogApi,
-        IResourceBuilder<ProjectResource> webApp)
+        IResourceBuilder<ProjectResource> webApp,
+        OpenAITarget openAITarget)
     {
         const string openAIName = "openai";
 
@@ -48,44 +56,76 @@ public static IDistributedApplicationBuilder AddOpenAI(this IDistributedApplicat
         const string chatName = "chatModel";
         const string chatModelName = "gpt-4.1-mini";
 
-        // to use an existing OpenAI resource as a connection string, add the following to the AppHost user secrets:
-        // "ConnectionStrings": {
-        //   "openai": "Key=<API Key>" (to use https://api.openai.com/)
-        //     -or-
-        //   "openai": "Endpoint=https://<name>.openai.azure.com/" (to use Azure OpenAI)
-        // }
-        if (builder.Configuration.GetConnectionString(openAIName) is string openAIConnectionString)
-        {
-            catalogApi.WithReference(
-                builder.AddConnectionString(textEmbeddingName, ReferenceExpression.Create($"{openAIConnectionString};Deployment={textEmbeddingModelName}")));
-            webApp.WithReference(
-                builder.AddConnectionString(chatName, ReferenceExpression.Create($"{openAIConnectionString};Deployment={chatModelName}")));
-        }
-        else
+        if (openAITarget != OpenAITarget.AzureOpenAI)
         {
-            // to use Azure provisioning, add the following to the AppHost user secrets:
-            // "Azure": {
-            //   "SubscriptionId": "<your subscription ID>",
-            //   "ResourceGroupPrefix": "<prefix>",
-            //   "Location": "<location>"
-            // }
+#pragma warning disable ASPIREINTERACTION001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
+            IResourceBuilder<ParameterResource>? endpoint = null;
+            if (openAITarget != OpenAITarget.OpenAI)
+            {
+                endpoint = builder.AddParameter("OpenAIEndpointParameter")
+                    .WithDescription("The Azure OpenAI endpoint to use, e.g. https://<name>.openai.azure.com/")
+                    .WithCustomInput(p => new()
+                    {
+                        Label = "Azure OpenAI Endpoint",
+                        InputType = InputType.Text,
+                        Value = "https://<name>.openai.azure.com/",
+                    });
+            }
 
-            var openAI = builder.AddAzureOpenAI(openAIName);
+            IResourceBuilder<ParameterResource>? key = null;
+            if (openAITarget is OpenAITarget.OpenAI or OpenAITarget.AzureOpenAIExistingWithKey)
+            {
+                key = builder.AddParameter("OpenAIKeyParameter", secret: true)
+                    .WithDescription("The OpenAI API key to use.")
+                    .WithCustomInput(p => new()
+                    {
+                        Label = "API Key",
+                        InputType = InputType.SecretText
+                    });
+            }
 
-            // to use an existing Azure OpenAI resource via provisioning, add the following to the AppHost user secrets:
-            // "Parameters": {
-            //   "openaiName": "<Azure OpenAI resource name>",
-            //   "openaiResourceGroup": "<Azure OpenAI resource group>"
-            // }
-            // - or -
-            // leave the parameters out to create a new Azure OpenAI resource
-            if (builder.Configuration["Parameters:openaiName"] is not null &&
-                builder.Configuration["Parameters:openaiResourceGroup"] is not null)
+            var chatModel = builder.AddParameter("ChatModelParameter")
+                .WithDescription("The chat model to use.")
+                .WithCustomInput(p => new()
+                {
+                    Label = "Chat Model",
+                    InputType = InputType.Text,
+                    Value = chatModelName,
+                });
+
+            var embeddingModel = builder.AddParameter("EmbeddingModelParameter")
+                .WithDescription("The embedding model to use.")
+                .WithCustomInput(p => new()
+                {
+                    Label = "Text Embedding Model",
+                    InputType = InputType.Text,
+                    Value = textEmbeddingModelName,
+                });
+#pragma warning restore ASPIREINTERACTION001
+
+            var openAIConnectionBuilder = new ReferenceExpressionBuilder();
+            if (endpoint is not null)
             {
-                openAI.AsExisting(
-                    builder.AddParameter("openaiName"),
-                    builder.AddParameter("openaiResourceGroup"));
+                openAIConnectionBuilder.Append($"Endpoint={endpoint}");
             }
+            if (key is not null)
+            {
+                openAIConnectionBuilder.Append($";Key={key}");
+            }
+            var openAIConnectionString = openAIConnectionBuilder.Build();
+
+            catalogApi.WithReference(builder.AddConnectionString(textEmbeddingName, cs =>
+            {
+                cs.Append($"{openAIConnectionString};Deployment={embeddingModel}");
+            }));
+            webApp.WithReference(builder.AddConnectionString(chatName, cs =>
+            {
+                cs.Append($"{openAIConnectionString};Deployment={chatModel}");
+            }));
+        }
+        else
+        {
+            var openAI = builder.AddAzureOpenAI(openAIName);
 
             var chat = openAI.AddDeployment(chatName, chatModelName, "2025-04-14")
                 .WithProperties(d =>

src/eShop.AppHost/Program.cs

@@ -78,7 +78,7 @@
 bool useOpenAI = false;
 if (useOpenAI)
 {
-    builder.AddOpenAI(catalogApi, webApp);
+    builder.AddOpenAI(catalogApi, webApp, OpenAITarget.OpenAI); // set to AzureOpenAI if you want to use Azure OpenAI
 }
 
 bool useOllama = false;