Fix SNAP 7.0 + Python 3 support

Dockerfile

@@ -3,17 +3,32 @@ FROM mrmoor/esa-snap:latest
 
 # install jdk and python3 with required modules
 RUN apt-get update && \
-    apt-get -y install default-jdk python python-pip git maven python-jpy
-RUN python -m pip install --user --upgrade setuptools wheel
+    apt-get -y install default-jdk python3 python3-pip git maven
+RUN python3 -m pip install --user --upgrade setuptools wheel
 
 # set JDK_HOME env
 ENV JDK_HOME="/usr/lib/jvm/default-java"
 ENV JAVA_HOME=$JDK_HOME
 ENV PATH=$PATH:/root/.local/bin
+ENV LD_LIBRARY_PATH=.
 
 # install snappy the SNAP python module
-RUN /usr/local/snap/bin/snappy-conf /usr/bin/python
+# Add Python3.7 support via fork : 
+# https://github.com/illumon-public/illumon-jpy/releases/download/1.20190816.73/deephaven_jpy-1.20190816.73-cp37-cp37m-linux_x86_64.whl
+RUN /usr/bin/python3 --version
+# Create ~/.snap temp directory to install from
+RUN /usr/local/snap/bin/snappy-conf /usr/bin/python3 || true
+RUN wget https://github.com/illumon-public/illumon-jpy/releases/download/1.20190816.73/deephaven_jpy-1.20190816.73-cp37-cp37m-linux_x86_64.whl
+RUN mv deephaven_jpy-1.20190816.73-cp37-cp37m-linux_x86_64.whl /root/.snap/snap-python/snappy/jpy-1.20190816.73-cp37-cp37m-linux_x86_64.whl
+
+# This ends with code 30 which may be a premonition of later failure, but hey we can run setup.py
+RUN cd /root/.snap/snap-python/snappy/ && \
+    /usr/bin/python3 ./snappyutil.py --snap_home /usr/local/snap --java_module /usr/local/snap/snap/modules/org-esa-snap-snap-python.jar \
+    --force --log_file ./snappyutil.log --jvm_max_mem 1G --java_home /usr/local/snap/jre --req_arch amd64 || true
+RUN cat /root/.snap/snap-python/snappy/snappyutil.log
 RUN cd /root/.snap/snap-python/snappy/ && \
-    python setup.py install
-RUN ln -s /root/.snap/snap-python/snappy /usr/lib/python2.7/dist-packages/snappy
+    python3 setup.py install
+RUN ln -s /root/.snap/snap-python/snappy /usr/local/lib/python3.7/dist-packages/snappy
+
+ENTRYPOINT ["/usr/bin/python3"]