(Feat) - LiteLLM Use UsernamePasswordCredential for Azure OpenAI (#7496)

* add get_azure_ad_token_from_username_password

* docs azure use username / password for auth

* update doc

* get_azure_ad_token_from_username_password

* test test_get_azure_ad_token_from_username_password

tests/llm_translation/test_azure_openai.py

@@ -211,3 +211,40 @@ class TestAzureEmbedding(BaseLLMEmbeddingTest):
 
     def get_custom_llm_provider(self) -> litellm.LlmProviders:
         return litellm.LlmProviders.AZURE
+
+
+@patch("azure.identity.UsernamePasswordCredential")
+@patch("azure.identity.get_bearer_token_provider")
+def test_get_azure_ad_token_from_username_password(
+    mock_get_bearer_token_provider, mock_credential
+):
+    from litellm.llms.azure.common_utils import (
+        get_azure_ad_token_from_username_password,
+    )
+
+    # Test inputs
+    client_id = "test-client-id"
+    username = "test-username"
+    password = "test-password"
+
+    # Mock the token provider function
+    mock_token_provider = lambda: "mock-token"
+    mock_get_bearer_token_provider.return_value = mock_token_provider
+
+    # Call the function
+    result = get_azure_ad_token_from_username_password(
+        client_id=client_id, azure_username=username, azure_password=password
+    )
+
+    # Verify UsernamePasswordCredential was called with correct arguments
+    mock_credential.assert_called_once_with(
+        client_id=client_id, username=username, password=password
+    )
+
+    # Verify get_bearer_token_provider was called
+    mock_get_bearer_token_provider.assert_called_once_with(
+        mock_credential.return_value, "https://cognitiveservices.azure.com/.default"
+    )
+
+    # Verify the result is the mock token provider
+    assert result == mock_token_provider