Don't upgrade pip if there are no requirements. (#1678)

Author: squidarth

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "truss"
-version = "0.9.96rc018"
+version = "0.9.97rc001"
 description = "A seamless bridge from model development to model delivery"
 license = "MIT"
 readme = "README.md"

truss/templates/base.Dockerfile.jinja

@@ -13,8 +13,10 @@ RUN $PYTHON_EXECUTABLE -c "import sys; \
     || { echo "ERROR: Supplied base image does not have {{ min_supported_python_version_in_custom_base_image }} <= python <= {{ max_supported_python_version_in_custom_base_image }}"; exit 1; }
 {% endblock %}
 
-RUN pip install --upgrade pip --no-cache-dir \
-    && rm -rf /root/.cache/pip
+# NB(nikhil): Only run `pip` if present in image, certain custom servers don't have it.
+RUN if command -v pip >/dev/null 2>&1; then \
+      pip install --upgrade pip --no-cache-dir && rm -rf /root/.cache/pip; \
+    fi
 
 {% block base_image_patch %}
 {% endblock %}

truss/tests/test_data/server.Dockerfile

@@ -9,8 +9,9 @@ RUN $PYTHON_EXECUTABLE -c "import sys; \
     and sys.version_info.minor <= 13 \
     else sys.exit(1)" \
     || { echo "ERROR: Supplied base image does not have 3.8 <= python <= 3.13"; exit 1; }
-RUN pip install --upgrade pip --no-cache-dir \
-    && rm -rf /root/.cache/pip
+RUN if command -v pip >/dev/null 2>&1; then \
+      pip install --upgrade pip --no-cache-dir && rm -rf /root/.cache/pip; \
+    fi
 ENV PYTHONUNBUFFERED="True"
 ENV DEBIAN_FRONTEND="noninteractive"
 RUN apt update && \