fix for wrong OpenAIClientOptions used with keyed OpenAIClient(s) (#11003)

* fix for wrong OpenAIClientOptions used with keyed OpenAIClient(s)

with keyed OpenAIClients

```
builder.AddKeyedOpenAIClient("openai");
builder.AddKeyedOpenAIClient("ionos");
```

assuming that at least one keyed OpenAIClient has a differnt endpoint,

```
{
  "ConnectionStrings": {
    "openai": "Key={account_key};"
    "ionos": "Endpoint=https://{openai_rest_api_url};Key={account_key};"
  }
}
```

 getting the client with

```
var client = serviceProvider.GetRequiredKeyedService<OpenAIClient>("ionos")
```

the client uses the key from the connectionstring but it still has the default enpoint https://api.openai.com/v1

The issue is that ConfigureOpenAI ignores the serviceKey and always get's the default OpenAIClientOptions instead of the one created with optionsName = servicekey.

This makes using keyed OpenAIClients virtually impossible because the main reason having multiple OpenAIClients is having different endpoints.

Fix #9543

* added unit test

* PR feedback

---------

Co-authored-by: Eric Erhardt <eric.erhardt@microsoft.com>

Author: Steinblock

src/Components/Aspire.OpenAI/AspireOpenAIExtensions.cs

@@ -124,7 +124,10 @@ OpenAIClient ConfigureOpenAI(IServiceProvider serviceProvider)
         {
             if (settings.Key is not null)
             {
-                var options = serviceProvider.GetRequiredService<IOptions<OpenAIClientOptions>>().Value;
+                var options = serviceKey is null ?
+                    serviceProvider.GetRequiredService<IOptions<OpenAIClientOptions>>().Value :
+                    serviceProvider.GetRequiredService<IOptionsMonitor<OpenAIClientOptions>>().Get(serviceKey);
+
                 return new OpenAIClient(new ApiKeyCredential(settings.Key), options);
             }
             else

tests/Aspire.OpenAI.Tests/AspireOpenAIExtensionsTests.cs

@@ -86,6 +86,40 @@ public void ReadsFromConnectionStringsFormats(string connectionString)
         Assert.NotNull(client);
     }
 
+    [Theory]
+    [InlineData("Endpoint=http://domain.com:12345;Key=abc123", false)]
+    [InlineData("Endpoint=http://domain.com:12345;Key=abc123", true)]
+    public void ReadsEndpointFromConnectionStrings(string connectionString, bool useKeyed)
+    {
+        var builder = Host.CreateEmptyApplicationBuilder(null);
+        builder.Configuration.AddInMemoryCollection([
+            new KeyValuePair<string, string?>("ConnectionStrings:openai", connectionString)
+        ]);
+
+        if (useKeyed)
+        {
+            builder.AddKeyedOpenAIClient("openai");
+        }
+        else
+        {
+            builder.AddOpenAIClient("openai");
+        }
+
+        using var host = builder.Build();
+        var client = useKeyed ?
+            host.Services.GetRequiredKeyedService<OpenAIClient>("openai") :
+            host.Services.GetRequiredService<OpenAIClient>();
+
+        Assert.NotNull(client);
+
+        var endpointField = client.GetType().GetField("_endpoint", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
+        Assert.NotNull(endpointField);
+
+        var endpoint = endpointField.GetValue(client);
+        Assert.NotNull(endpoint);
+        Assert.Equal("http://domain.com:12345/", endpoint.ToString());
+    }
+
     [Theory]
     [InlineData("")]
     [InlineData("Endpoint=http://domain.com:12345")]