Enable paligemma2 (#2807)

* feat: support loading gemma2 as vlm text model

* feat: add test for paligemma2

integration-tests/models/__snapshots__/test_flash_pali_gemma2/test_flash_pali_gemma_image.json

+{
+  "details": {
+    "best_of_sequences": null,
+    "finish_reason": "length",
+    "generated_tokens": 20,
+    "prefill": [],
+    "seed": null,
+    "tokens": [
+      {
+        "id": 108,
+        "logprob": -0.73046875,
+        "special": false,
+        "text": "\n"
+      },
+      {
+        "id": 30234,
+        "logprob": -2.328125,
+        "special": false,
+        "text": "Brown"
+      },
+      {
+        "id": 108,
+        "logprob": -0.12060547,
+        "special": false,
+        "text": "\n"
+      },
+      {
+        "id": 3726,
+        "logprob": -1.7734375,
+        "special": false,
+        "text": "Car"
+      },
+      {
+        "id": 108,
+        "logprob": -0.041503906,
+        "special": false,
+        "text": "\n"
+      },
+      {
+        "id": 2915,
+        "logprob": -1.796875,
+        "special": false,
+        "text": "Color"
+      },
+      {
+        "id": 108,
+        "logprob": -0.039794922,
+        "special": false,
+        "text": "\n"
+      },
+      {
+        "id": 19178,
+        "logprob": -1.96875,
+        "special": false,
+        "text": "Cool"
+      },
+      {
+        "id": 108,
+        "logprob": -0.080566406,
+        "special": false,
+        "text": "\n"
+      },
+      {
+        "id": 40544,
+        "logprob": -2.1875,
+        "special": false,
+        "text": "Decor"
+      },
+      {
+        "id": 108,
+        "logprob": -0.033935547,
+        "special": false,
+        "text": "\n"
+      },
+      {
+        "id": 13936,
+        "logprob": -1.6328125,
+        "special": false,
+        "text": "Green"
+      },
+      {
+        "id": 108,
+        "logprob": -0.16210938,
+        "special": false,
+        "text": "\n"
+      },
+      {
+        "id": 955,
+        "logprob": -2.015625,
+        "special": false,
+        "text": "..."
+      },
+      {
+        "id": 108,
+        "logprob": -0.14746094,
+        "special": false,
+        "text": "\n"
+      },
+      {
+        "id": 955,
+        "logprob": -0.73828125,
+        "special": false,
+        "text": "..."
+      },
+      {
+        "id": 108,
+        "logprob": -0.051513672,
+        "special": false,
+        "text": "\n"
+      },
+      {
+        "id": 955,
+        "logprob": -0.34765625,
+        "special": false,
+        "text": "..."
+      },
+      {
+        "id": 108,
+        "logprob": -0.020141602,
+        "special": false,
+        "text": "\n"
+      },
+      {
+        "id": 955,
+        "logprob": -0.11767578,
+        "special": false,
+        "text": "..."
+      }
+    ],
+    "top_tokens": null
+  },
+  "generated_text": "\nBrown\nCar\nColor\nCool\nDecor\nGreen\n...\n...\n...\n..."
+}

integration-tests/models/test_flash_pali_gemma2.py

+import pytest
+
+
+@pytest.fixture(scope="module")
+def flash_pali_gemma_handle(launcher):
+    with launcher(
+        "google/paligemma2-3b-pt-224",
+    ) as handle:
+        yield handle
+
+
+@pytest.fixture(scope="module")
+async def flash_pali_gemma(flash_pali_gemma_handle):
+    await flash_pali_gemma_handle.health(300)
+    return flash_pali_gemma_handle.client
+
+
+async def test_flash_pali_gemma_image(flash_pali_gemma, response_snapshot):
+    car_image = "https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/transformers/tasks/car.jpg"
+    response = await flash_pali_gemma.generate(
+        f"![]({car_image})",
+        max_new_tokens=20,
+    )
+    assert (
+        response.generated_text
+        == "\nBrown\nCar\nColor\nCool\nDecor\nGreen\n...\n...\n...\n..."
+    )
+
+    assert response == response_snapshot

server/text_generation_server/models/custom_modeling/vlm.py

@@ -17,6 +17,12 @@ def load_text_model(prefix, config, weights, name=None):
         )
 
         return FlashGemmaForCausalLM(prefix, config, weights, causal=False)
+    elif config.model_type == "gemma2":
+        from text_generation_server.models.custom_modeling.flash_gemma2_modeling import (
+            FlashGemma2ForCausalLM,
+        )
+
+        return FlashGemma2ForCausalLM(prefix, config, weights)
     elif config.model_type == "paligemma":
         from text_generation_server.models.custom_modeling.flash_gemma_modeling import (
             FlashGemmaForCausalLM,