Fix the installation of the scala plugin. It must be global.

tasks/main.yml

@@ -5,13 +5,16 @@
     user: name={{ jupyter_hub_user }} home={{ jupyter_hub_user_home }} createhome=no shell=/usr/sbin/nologin system=yes
 
   - name: Create the jupyterhub home, if it does not exist
-    file: dest={{ jupyter_hub_user_home }} owner={{ jupyter_hub_user }} group={{ jupyter_hub_user }} state=directory recurse=yes
+    file: dest={{ jupyter_hub_user_home }} owner={{ jupyter_hub_user }} group={{ jupyter_hub_user }} state=directory recurse=yes mode='0750'
+
+  - name: Create the jupyterhub base directory
+    file: dest={{ jupyter_hub_base_dir }} owner=root group=root state=directory recurse=yes mode='0755'
 
   - name: Create a configuration directory for jupyter hub
-    file: dest={{ jupyter_hub_conf_dir }} state=directory owner=root group={{ jupyter_hub_user }} mode=0750
+    file: dest={{ jupyter_hub_conf_dir }} state=directory owner=root group={{ jupyter_hub_user }} mode='0750'
 
   - name: Create a data directory for jupyter hub
-    file: dest={{ jupyter_hub_data_dir }} state=directory owner={{ jupyter_hub_user }} group={{ jupyter_hub_user }} mode=0750
+    file: dest={{ jupyter_hub_data_dir }} state=directory owner={{ jupyter_hub_user }} group={{ jupyter_hub_user }} mode='0755'
 
   - name: Create a log directory for jupyter hub
     file: dest={{ jupyter_hub_logdir }} state=directory owner={{ jupyter_hub_user }} group={{ jupyter_hub_user }} mode=0750
@@ -51,7 +54,7 @@
 - name: Jupyterhub and SPARK
   block:
     - name: Ensure that the spark configuration directory exists
-      file: dest=/usr/share/jupyter/kernels/pyspark2 state=directory
+      file: dest=/usr/share/jupyter/kernels/pyspark2 state=directory recurse=yes mode='0755'
 
     - name: Install the spark configuration
       copy: src=spark-kernel.json dest=/usr/share/jupyter/kernels/pyspark2/kernel.json
@@ -65,14 +68,20 @@
     - name: Download the coursier executable
       get_url: url=https://git.io/coursier-cli-linux dest=/usr/local/bin/coursier owner=root group=root mode='0555'
 
+    - name: Create the coursier cache directory
+      file: dest={{ jupyter_hub_coursier_cache_dir }} owner=root group=root state=directory recurse=yes mode='0755'
+
     - name: Check if the scala support for jupyter is already installed
-      stat: path="/root/.local/share/jupyter/kernels/scala"
+      stat: path="/usr/local/share/jupyter/kernels/scala/launcher.jar"
       register: jupyter_scala
 
     - name: Integrate Spark and Scala
-      command: /usr/local/bin/coursier launch --fork almond:0.5.0 --scala {{ jupyter_spark_scala_version }} -- --install
+      command: /usr/local/bin/coursier launch --cache {{ jupyter_hub_coursier_cache_dir }} --fork almond:0.5.0 --scala {{ jupyter_spark_scala_version }} -- --install --global --force
       when: not jupyter_scala.stat.exists
 
+    - name: Fix the scala launcher permissions
+      file: dest="/usr/local/share/jupyter/kernels/scala/launcher.jar" mode='0644'
+
   when:
     - jupyter_is_hadoop_node
   tags: [ 'jupyter', 'jupyter_hub', 'spark' ]

vars/main.yml

@@ -14,6 +14,7 @@ jupyter_hub_conf: '{{ jupyter_hub_conf_dir }}/jupyterhub_config.py'
 jupyter_hub_venv_dir: '/opt/{{ jupyter_hub_venv }}'
 jupyter_hub_logdir: /var/log/jupyter
 jupyter_hub_user: jhub
+jupyter_hub_coursier_cache_dir: '{{ jupyter_hub_base_dir }}/cs_cache'
 
 py3_env_install: True
 # Always install everything