I haven't yet managed to get Spark, Scala, and Jupyter to co-operate. Does anyone have a simple recipe? Which version of each component did you use?
Apache Toree is compatible with DataProc's 1.0 image, which currently includes Spark 1.6.1. I had unsuccessfully tried to use it with the preview image, which includes Spark 2.0 preview. To install Toree on the DataProc master you can run
sudo apt install python3-pip
pip3 install --user jupyter
export SPARK_HOME=/usr/lib/spark
pip3 install --pre --user toree
export PATH=$HOME/.local/bin:$PATH
jupyter toree install --user --spark_home=$SPARK_HOME