add prometheus exporter for groupfolder metrics

tasks/base.yml

@@ -115,3 +115,31 @@
     state: link
   notify:
   - restart nginx
+
+- name:
+  when: nextcloud.prometheus_exporter.enabled
+  block:
+  - name: install python and modules
+    apt:
+      pkg:
+        - python3
+        - python3-prometheus-client
+        - python3-schedule
+
+  - name: copy exporter script
+    notify: restart prometheus exporter
+    template:
+      src: nextcloud-prometheus-exporter.py.j2
+      dest: /usr/local/bin/nextcloud-prometheus-exporter.py
+      owner: root
+      group: root
+      mode: 0755
+
+  - name: copy systemd service file
+    notify: restart prometheus exporter
+    copy:
+      src: nextcloud-prometheus-exporter.service
+      dest: /etc/systemd/system
+      owner: root
+      group: root
+      mode: 0644