r/wal-g-pg: Schedule daily backups

WAL archives are not much good without a base backup onto which they
can be applied.  Thus, we need to schedule WAL-G to create and upload a
backup periodically.

roles/wal-g-pg/tasks/main.yml

@@ -34,5 +34,40 @@
   tags:
   - selinux
 
+- name: ensure wal-g backup timer is installed
+  template:
+    src: wal-g-backup.timer.j2
+    dest: /etc/systemd/system/wal-g-backup.timer
+    owner: root
+    group: root
+    mode: u=rw,go=r
+  notify:
+  - restart wal-g backup timer
+  tags:
+  - systemd
+- name: ensure wal-g backup service is installed
+  copy:
+    src: wal-g-backup.service
+    dest: /etc/systemd/system/wal-g-backup.service
+    owner: root
+    group: root
+    mode: u=rw,go=r
+  tags:
+  - systemd
+
+- name: ensure wal-g backup timer is enabled
+  systemd:
+    name: wal-g-backup.timer
+    enabled: true
+  tags:
+  - service
+
 - name: flush handlers
   meta: flush_handlers
+
+- name: ensure wal-g backup timer is running
+  systemd:
+    name: wal-g-backup.timer
+    state: started
+  tags:
+  - service