(Feat) pass through vertex - allow using credentials defined on litellm router for vertex pass through (#8100)

* test_add_vertex_pass_through_deployment

* VertexPassThroughRouter

* fix use_in_pass_through

* VertexPassThroughRouter

* fix vertex_credentials

* allow using _initialize_deployment_for_pass_through

* test_add_vertex_pass_through_deployment

* _set_default_vertex_config

* fix verbose_proxy_logger

* fix use_in_pass_through

* fix _get_token_and_url

* test_get_vertex_location_from_url

* test_get_vertex_credentials_none

* run pt unit testing again

* fix add_vertex_credentials

* test_adding_deployments.py

* rename file

tests/router_unit_tests/test_router_adding_deployments.py

@@ -0,0 +1,170 @@
+import sys, os
+import pytest
+
+sys.path.insert(
+    0, os.path.abspath("../..")
+)  # Adds the parent directory to the system path
+from litellm import Router
+from litellm.router import Deployment, LiteLLM_Params
+from unittest.mock import patch
+import json
+
+
+def test_initialize_deployment_for_pass_through_success():
+    """
+    Test successful initialization of a Vertex AI pass-through deployment
+    """
+    router = Router(model_list=[])
+    deployment = Deployment(
+        model_name="vertex-test",
+        litellm_params=LiteLLM_Params(
+            model="vertex_ai/test-model",
+            vertex_project="test-project",
+            vertex_location="us-central1",
+            vertex_credentials=json.dumps(
+                {"type": "service_account", "project_id": "test"}
+            ),
+            use_in_pass_through=True,
+        ),
+    )
+
+    # Test the initialization
+    router._initialize_deployment_for_pass_through(
+        deployment=deployment,
+        custom_llm_provider="vertex_ai",
+        model="vertex_ai/test-model",
+    )
+
+    # Verify the credentials were properly set
+    from litellm.proxy.vertex_ai_endpoints.vertex_endpoints import (
+        vertex_pass_through_router,
+    )
+
+    vertex_creds = vertex_pass_through_router.get_vertex_credentials(
+        project_id="test-project", location="us-central1"
+    )
+    assert vertex_creds.vertex_project == "test-project"
+    assert vertex_creds.vertex_location == "us-central1"
+    assert vertex_creds.vertex_credentials == json.dumps(
+        {"type": "service_account", "project_id": "test"}
+    )
+
+
+def test_initialize_deployment_for_pass_through_missing_params():
+    """
+    Test initialization fails when required Vertex AI parameters are missing
+    """
+    router = Router(model_list=[])
+    deployment = Deployment(
+        model_name="vertex-test",
+        litellm_params=LiteLLM_Params(
+            model="vertex_ai/test-model",
+            # Missing required parameters
+            use_in_pass_through=True,
+        ),
+    )
+
+    # Test that initialization raises ValueError
+    with pytest.raises(
+        ValueError,
+        match="vertex_project, vertex_location, and vertex_credentials must be set",
+    ):
+        router._initialize_deployment_for_pass_through(
+            deployment=deployment,
+            custom_llm_provider="vertex_ai",
+            model="vertex_ai/test-model",
+        )
+
+
+def test_initialize_deployment_for_pass_through_unsupported_provider():
+    """
+    Test initialization with an unsupported provider
+    """
+    router = Router(model_list=[])
+    deployment = Deployment(
+        model_name="unsupported-test",
+        litellm_params=LiteLLM_Params(
+            model="unsupported/test-model",
+            use_in_pass_through=True,
+        ),
+    )
+
+    # Should not raise an error, but log a warning
+    router._initialize_deployment_for_pass_through(
+        deployment=deployment,
+        custom_llm_provider="unsupported_provider",
+        model="unsupported/test-model",
+    )
+
+
+def test_initialize_deployment_when_pass_through_disabled():
+    """
+    Test that initialization simply exits when use_in_pass_through is False
+    """
+    router = Router(model_list=[])
+    deployment = Deployment(
+        model_name="vertex-test",
+        litellm_params=LiteLLM_Params(
+            model="vertex_ai/test-model",
+        ),
+    )
+
+    # This should exit without error, even with missing vertex parameters
+    router._initialize_deployment_for_pass_through(
+        deployment=deployment,
+        custom_llm_provider="vertex_ai",
+        model="vertex_ai/test-model",
+    )
+
+    # If we reach this point, the test passes as the method exited without raising any errors
+    assert True
+
+
+def test_add_vertex_pass_through_deployment():
+    """
+    Test adding a Vertex AI deployment with pass-through configuration
+    """
+    router = Router(model_list=[])
+
+    # Create a deployment with Vertex AI pass-through settings
+    deployment = Deployment(
+        model_name="vertex-test",
+        litellm_params=LiteLLM_Params(
+            model="vertex_ai/test-model",
+            vertex_project="test-project",
+            vertex_location="us-central1",
+            vertex_credentials=json.dumps(
+                {"type": "service_account", "project_id": "test"}
+            ),
+            use_in_pass_through=True,
+        ),
+    )
+
+    # Add deployment to router
+    router.add_deployment(deployment)
+
+    # Get the vertex credentials from the router
+    from litellm.proxy.vertex_ai_endpoints.vertex_endpoints import (
+        vertex_pass_through_router,
+    )
+
+    # current state of pass-through vertex router
+    print("\n vertex_pass_through_router.deployment_key_to_vertex_credentials\n\n")
+    print(
+        json.dumps(
+            vertex_pass_through_router.deployment_key_to_vertex_credentials,
+            indent=4,
+            default=str,
+        )
+    )
+
+    vertex_creds = vertex_pass_through_router.get_vertex_credentials(
+        project_id="test-project", location="us-central1"
+    )
+
+    # Verify the credentials were properly set
+    assert vertex_creds.vertex_project == "test-project"
+    assert vertex_creds.vertex_location == "us-central1"
+    assert vertex_creds.vertex_credentials == json.dumps(
+        {"type": "service_account", "project_id": "test"}
+    )