Use explicit MetaX Python and vLLM paths

Dockerfile

@@ -1,12 +1,17 @@
 ARG BASE_IMAGE=harbor.4pd.io/dooke/vllm/vllm/vllm-openai:v0.11.0
 FROM ${BASE_IMAGE}
 
+ARG PYTHON_BIN=python3
+ARG VLLM_BIN=vllm
+ENV MODELHUB_COMPAT_PYTHON=${PYTHON_BIN}
+
 COPY engine_compat.py /opt/modelhub/engine_compat.py
 COPY vllm_wrapper.sh /opt/modelhub/vllm_wrapper.sh
 
 RUN set -eu; \
-    python3 -m py_compile /opt/modelhub/engine_compat.py; \
-    vllm_bin="$(command -v vllm)"; \
+    "$PYTHON_BIN" -m py_compile /opt/modelhub/engine_compat.py; \
+    if [ "$VLLM_BIN" = vllm ]; then vllm_bin="$(command -v vllm)"; else vllm_bin="$VLLM_BIN"; fi; \
+    test -x "$vllm_bin"; \
     mv "$vllm_bin" "$(dirname "$vllm_bin")/vllm_real"; \
     cp /opt/modelhub/vllm_wrapper.sh "$vllm_bin"; \
     chmod 0755 "$vllm_bin" /opt/modelhub/engine_compat.py