(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

litellm/llms/azure/common_utils.py

@@ -137,3 +137,44 @@ def get_azure_ad_token_from_entrata_id(
     verbose_logger.debug("token_provider %s", token_provider)
 
     return token_provider
+
+
+def get_azure_ad_token_from_username_password(
+    client_id: str,
+    azure_username: str,
+    azure_password: str,
+    scope: str = "https://cognitiveservices.azure.com/.default",
+) -> Callable[[], str]:
+    """
+    Get Azure AD token provider from `client_id`, `azure_username`, and `azure_password`
+
+    Args:
+        client_id: str
+        azure_username: str
+        azure_password: str
+        scope: str
+
+    Returns:
+        callable that returns a bearer token.
+    """
+    from azure.identity import UsernamePasswordCredential, get_bearer_token_provider
+
+    verbose_logger.debug(
+        "client_id %s, azure_username %s, azure_password %s",
+        client_id,
+        azure_username,
+        azure_password,
+    )
+    credential = UsernamePasswordCredential(
+        client_id=client_id,
+        username=azure_username,
+        password=azure_password,
+    )
+
+    verbose_logger.debug("credential %s", credential)
+
+    token_provider = get_bearer_token_provider(credential, scope)
+
+    verbose_logger.debug("token_provider %s", token_provider)
+
+    return token_provider