fix python install

Author: soulgalore

Dockerfile

@@ -2,22 +2,26 @@ FROM sitespeedio/node:ubuntu-24-04-nodejs-22.13.0
 
 ARG TARGETPLATFORM
 
-# Lets install all dependencies for VisualMetrics
+# Install dependencies
 RUN export BUILD=$(if [ "$TARGETPLATFORM" = "linux/amd64" ] ; then echo "amd64"; else echo "arm64"; fi) \
   buildDeps='wget ca-certificates build-essential' && \
   apt-get update -y && apt-get install -y \
   libjpeg-dev \
   imagemagick \
   python3 \
+  python3-venv \
   python3-dev \
-  python3-pip \
   xz-utils \
   $buildDeps \
-  --no-install-recommends --force-yes && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
-  python3 -m pip install --upgrade pip && \
-  python3 -m pip install --upgrade setuptools && \
-  python3 -m pip install --no-cache-dir pyssim OpenCV-Python Numpy image && \
+  --no-install-recommends --force-yes && \
+  rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
+  python3 -m venv /opt/venv && \
+  /opt/venv/bin/pip install --upgrade pip setuptools && \
+  /opt/venv/bin/pip install --no-cache-dir pyssim OpenCV-Python Numpy image && \
   wget https://johnvansickle.com/ffmpeg/old-releases/ffmpeg-5.1.1-$BUILD-static.tar.xz && \
-  tar --strip-components 1 -C /usr/bin -xf ffmpeg-5.1.1-$BUILD-static.tar.xz --wildcards ffmpeg*/ff*  && \
+  tar --strip-components 1 -C /usr/bin -xf ffmpeg-5.1.1-$BUILD-static.tar.xz --wildcards ffmpeg*/ff* && \
   rm ffmpeg-5.1.1-$BUILD-static.tar.xz && \
-  apt-get purge -y --auto-remove $buildDeps
+  apt-get purge -y --auto-remove $buildDeps
+
+# Set the virtual environment as the default Python environment
+ENV PATH="/opt/venv/bin:$PATH"