Inline Dockerfile entrypoint.sh creation

example-dockerfile-entrypoint.sh

# Create a script to load environment variables from mounted secrets
RUN echo '#!/bin/sh' > /app/entrypoint.sh && \
    echo 'if [ -d "/secrets" ] && [ -f "/secrets/.env" ]; then' >> /app/entrypoint.sh && \
    echo '  cp /secrets/.env /app/.env' >> /app/entrypoint.sh && \
    echo '  echo "Loaded environment from mounted secret"' >> /app/entrypoint.sh && \
    echo 'fi' >> /app/entrypoint.sh && \
    echo 'exec node src/server.js' >> /app/entrypoint.sh && \
    chmod +x /app/entrypoint.sh && \
    chown nodeapp:nodeapp /app/entrypoint.sh