Backup etcd data before restarting etcd

etcd is crucial part of kubernetes cluster. Ansible restarts etcd on
reconfiguration. Backup helps operator to restore cluster manually in
case of any issues.

Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

roles/etcd/handlers/backup.yml

@@ -0,0 +1,45 @@
+---
+- name: Backup etcd data
+  command: /bin/true
+  notify:
+    - Refresh Time Fact
+    - Set etcd Backup Directory Prefix
+    - Set Backup Directory
+    - Create Backup Directory
+    - Backup etcd v2 data
+    - Backup etcd v3 data
+  when: etcd_cluster_is_healthy.rc == 0
+
+- name: Refresh Time Fact
+  setup: filter=ansible_date_time
+
+- name: Set etcd Backup Directory Prefix
+  set_fact:
+    etcd_backup_prefix: '/var/backups'
+
+- name: Set Backup Directory
+  set_fact:
+    etcd_backup_directory: "{{ etcd_backup_prefix }}/etcd-{{ ansible_date_time.date }}_{{ ansible_date_time.time }}"
+
+- name: Create Backup Directory
+  file:
+    path: "{{ etcd_backup_directory }}"
+    state: directory
+    owner: root
+    group: root
+    mode: 0600
+
+- name: Backup etcd v2 data
+  command: "{{ bin_dir }}/etcdctl backup --data-dir {{ etcd_data_dir }} --backup-dir {{ etcd_backup_directory }}"
+  environment:
+    ETCDCTL_API: 2
+  retries: 3
+  delay: "{{ retry_stagger | random + 3 }}"
+
+- name: Backup etcd v3 data
+  command: "{{ bin_dir }}/etcdctl --endpoints={{ etcd_access_addresses }} snapshot save {{ etcd_backup_directory }}/snapshot.db"
+  environment:
+    ETCDCTL_API: 3
+  retries: 3
+  delay: "{{ retry_stagger | random + 3 }}"
+

roles/etcd/handlers/main.yml

@@ -2,10 +2,13 @@
 - name: restart etcd
   command: /bin/true
   notify:
+    - Backup etcd data
     - etcd | reload systemd
     - reload etcd
     - wait for etcd up
 
+- include: backup.yml
+
 - name: etcd | reload systemd
   command: systemctl daemon-reload