community: add OCI Endpoint (#14250)

- **Description:** 
- [OCI Data
Science](https://docs.oracle.com/en-us/iaas/data-science/using/home.htm)
is a fully managed and serverless platform for data science teams to
build, train, and manage machine learning models in the Oracle Cloud
Infrastructure. This PR add integration for using LangChain with an LLM
hosted on a [OCI Data Science Model
Deployment](https://docs.oracle.com/en-us/iaas/data-science/using/model-dep-about.htm).
To authenticate,
[oracle-ads](https://accelerated-data-science.readthedocs.io/en/latest/user_guide/cli/authentication.html)
has been used to automatically load credentials for invoking endpoint.
- **Issue:** None
- **Dependencies:** `oracle-ads`
- **Tag maintainer:** @baskaryan
- **Twitter handle:** None

---------

Co-authored-by: Erick Friis <erick@langchain.dev>

libs/community/tests/unit_tests/llms/test_imports.py

@@ -49,6 +49,8 @@ EXPECT_ALL = [
     "Modal",
     "MosaicML",
     "Nebula",
+    "OCIModelDeploymentTGI",
+    "OCIModelDeploymentVLLM",
     "NIBittensorLLM",
     "NLPCloud",
     "Ollama",

libs/community/tests/unit_tests/llms/test_oci_model_deployment_endpoint.py

@@ -0,0 +1,46 @@
+"""Test OCI Data Science Model Deployment Endpoint."""
+import pytest
+import responses
+from pytest_mock import MockerFixture
+
+from langchain_community.llms import OCIModelDeploymentTGI, OCIModelDeploymentVLLM
+
+
+@pytest.mark.requires("ads")
+@responses.activate
+def test_call_vllm(mocker: MockerFixture) -> None:
+    """Test valid call to oci model deployment endpoint."""
+    endpoint = "https://MD_OCID/predict"
+    responses.add(
+        responses.POST,
+        endpoint,
+        json={
+            "choices": [{"index": 0, "text": "This is a completion."}],
+        },
+        status=200,
+    )
+    mocker.patch("ads.common.auth.default_signer", return_value=dict(signer=None))
+
+    llm = OCIModelDeploymentVLLM(endpoint=endpoint, model="my_model")
+    output = llm.invoke("This is a prompt.")
+    assert isinstance(output, str)
+
+
+@pytest.mark.requires("ads")
+@responses.activate
+def test_call_tgi(mocker: MockerFixture) -> None:
+    """Test valid call to oci model deployment endpoint."""
+    endpoint = "https://MD_OCID/predict"
+    responses.add(
+        responses.POST,
+        endpoint,
+        json={
+            "generated_text": "This is a completion.",
+        },
+        status=200,
+    )
+    mocker.patch("ads.common.auth.default_signer", return_value=dict(signer=None))
+
+    llm = OCIModelDeploymentTGI(endpoint=endpoint)
+    output = llm.invoke("This is a prompt.")
+    assert isinstance(output, str)