Install a filter to suppress the no-nodejs warning

Dockerfile

@@ -29,3 +29,14 @@ ENV PATH="/sage:$PATH"
 
 # Start in the home directory of the user
 WORKDIR /home/${NB_USER}
+
+# Create the jupyter_lab_config.py file with a custom logging filter to
+# suppress the perpetual nodejs warning
+RUN mkdir -p /home/${NB_USER}/.jupyter
+RUN echo "\
+import logging\n\
+class NoNodeJSWarningFilter(logging.Filter):\n\
+    def filter(self, record):\n\
+        return 'Could not determine jupyterlab build status without nodejs' not in record.getMessage()\n\
+logging.getLogger('LabApp').addFilter(NoNodeJSWarningFilter())\n\
+" > /home/${NB_USER}/.jupyter/jupyter_lab_config.py