added backup support

tasks/backup.yml

@@ -0,0 +1,21 @@
+- name: add postgresql backup folder
+  file:
+    path: /opt/postgresbackup/
+    state: directory
+    owner: postgres
+    group: postgres
+    mode: '750'
+
+- name: add backup cronjob for easier backup/restore
+  cron:
+    name: db backup
+    job: '/usr/bin/pg_dumpall | gzip > /opt/postgresbackup/$(date "+\%Y\%m\%d-\%H\%M.sql.gz")'
+    user: postgres
+    hour: "*/4"
+    minute: 45
+
+- name: add backup cleanup cronjob
+  cron:
+    name: db backup cleanup
+    job: 'find /opt/postgresbackup/* -mtime +{{ postgresql.backup.keep_days }} -type f -exec rm {} \;'
+    special_time: daily