Stretch support

- Support Debian Stretch (MariaDB debian/upstream + Galera)
- Doc updated
- New travis tests (with Vagrant)
- Drop support of mysql_innodb_additional_mem_pool_size
- Xtrabackup optionnal installation + package name updatable
- Fix many issues with replication (Ansible 2.3)
- Auto-retreive master IP address on tests
- MySQL tools per OS release

tasks/replication/slave/import_data.yml

@@ -1,7 +1,6 @@
 ---
 
 # Doc: https://www.percona.com/doc/percona-xtrabackup/2.1/howtos/recipes_ibkx_gtid.html
-
 - name: WAIT_FOR | source data (prevent rsync bug) - TODO find another hack
   wait_for: host={{ mysql_slave_import_from }} port=22
 
@@ -26,14 +25,15 @@
 
 - name: SET_FACT | related to mysql datadir
   set_fact:
-    mysql_mysql_datadir: "{{ datadir.msg[0][1] }}"
-    mysql_binlog_info: "{{ datadir.msg[0][1] }}/xtrabackup_binlog_info"
+    mysql_mysql_datadir: "{{ datadir.msg }}"
+    mysql_binlog_info: "{{ datadir.msg }}/xtrabackup_binlog_info"
 
 - name: SERVICE | Stop MySQL before importing data
   service: name=mysql state=stopped
 
+# TODO: add an "ignore warning"
 - name: COMMAND | Sync backup to slave - TODO remove vagrant as static user (see why mysql_backup_user is not working)
-  shell: "sudo -E rsync --rsync-path='sudo rsync' -a -e 'ssh -o StrictHostKeyChecking=no' vagrant@{{ mysql_slave_import_from }}:{{ mysql_backup_dir }}/ {{ mysql_mysql_datadir }}/"
+  shell: "sudo -E rsync --rsync-path='sudo rsync' -a -e 'ssh -o StrictHostKeyChecking=no' {{ mysql_backup_user }}@{{ mysql_slave_import_from }}:{{ mysql_backup_dir }}/ {{ mysql_mysql_datadir }}/"
   become: no
 
 - name: FILE | Re-apply owner

tasks/replication/slave/replication.yml

@@ -20,4 +20,3 @@
 
 - name: MYSQL_REPLICATION | Start slave
   mysql_replication: mode=startslave
-

tasks/replication/slave/ssh.yml

@@ -0,0 +1,19 @@
+---
+
+- name: SHELL | Create SSH key if needed on slave
+  shell: "ssh-keygen -b 2048 -t rsa -f {{ ansible_env.HOME }}/.ssh/id_rsa -q -N ''"
+  args:
+    creates: "{{ ansible_env.HOME }}/.ssh/id_rsa"
+
+- name: COMMAND | Get pub key
+  command: cat {{ ansible_env.HOME }}/.ssh/id_rsa.pub
+  register: pub_key
+  changed_when: false
+
+- name: AUTHORIZED_KEY | Auth slave to backup host
+  authorized_key:
+    user: "{{ mysql_backup_user }}"
+    state: present
+    key: "{{ pub_key.stdout }}"
+  delegate_to: "{{ mysql_slave_import_from }}"
+  become: yes