added backups

defaults/main.yml

 mongodb:
   version: "4.2"
+  backup:
+    enable: true
+    keep_days: 2

tasks/backup.yml

+- name: add mongodb backup folder
+  file:
+    path: /opt/mongodbbackup/
+    state: directory
+    owner: root
+    group: root
+    mode: '750'
+
+- name: add backup cronjob for easier backup/restore
+  cron:
+    name: mongodb backup
+    job: '/usr/bin/mongodump --gzip --archive=/opt/mongodbbackup/$(date "+\%Y\%m\%d-\%H\%M.dump.gz")'
+    user: root
+    hour: "*/4"
+    minute: 45
+
+- name: add backup cleanup cronjob
+  cron:
+    name: mongodb backup cleanup
+    job: 'find /opt/mongodbbackup/* -mtime +{{ mongodb.backup.keep_days }} -type f -exec rm {} \;'
+    special_time: daily

tasks/main.yml

@@ -12,3 +12,7 @@
     name: mongod
     daemon_reload: yes
     enabled: yes
+
+- include_tasks: backup.yml
+  when:
+  - mongodb.backup.enable