reduce files in home directory

- add a few missing `--system` flags to conda config
- install default notebook config to /etc/jupyter instead of ~/.jupyter
- add a few missing `conda clean`s

all-spark-notebook/Dockerfile

@@ -20,7 +20,7 @@ RUN apt-get update && \
 USER $NB_USER
 
 # R packages
-RUN conda config --add channels r && \
+RUN conda config --system --add channels r && \
     conda install --quiet --yes \
     'r-base=3.3.2' \
     'r-irkernel=0.7*' \
@@ -32,5 +32,6 @@ RUN pip --no-cache-dir install https://dist.apache.org/repos/dist/dev/incubator/
 RUN jupyter toree install --sys-prefix
 
 # Spylon-kernel
-RUN conda install --quiet --yes 'spylon-kernel=0.2*'
+RUN conda install --quiet --yes 'spylon-kernel=0.2*' && \
+    conda clean -tipsy
 RUN python -m spylon_kernel install --sys-prefix

base-notebook/Dockerfile

@@ -53,7 +53,6 @@ USER $NB_USER
 
 # Setup jovyan home directory
 RUN mkdir /home/$NB_USER/work && \
-    mkdir /home/$NB_USER/.jupyter && \
     echo "cacert=/etc/ssl/certs/ca-certificates.crt" > /home/$NB_USER/.curlrc
 
 # Install conda as jovyan
@@ -87,8 +86,7 @@ CMD ["start-notebook.sh"]
 COPY start.sh /usr/local/bin/
 COPY start-notebook.sh /usr/local/bin/
 COPY start-singleuser.sh /usr/local/bin/
-COPY jupyter_notebook_config.py /home/$NB_USER/.jupyter/
-RUN chown -R $NB_USER:users /home/$NB_USER/.jupyter
+COPY jupyter_notebook_config.py /etc/jupyter/
 
 # Switch back to jovyan to avoid accidental container runs as root
 USER $NB_USER

datascience-notebook/Dockerfile

@@ -26,7 +26,7 @@ RUN echo "deb http://ppa.launchpad.net/staticfloat/juliareleases/ubuntu trusty m
 USER $NB_USER
 
 # R packages including IRKernel which gets installed globally.
-RUN conda config --add channels r && \
+RUN conda config --system --add channels r && \
     conda install --quiet --yes \
     'rpy2=2.8*' \
     'r-base=3.3.2' \

r-notebook/Dockerfile

@@ -17,7 +17,7 @@ RUN apt-get update && \
 USER $NB_USER
 
 # R packages
-RUN conda config --add channels r && \
+RUN conda config --system --add channels r && \
     conda install --quiet --yes \
     'r-base=3.3.2' \
     'r-irkernel=0.7*' \