The galera cnf can be the same template across...

nodes.

mariadb.yml

@@ -5,9 +5,9 @@
   roles:
       - mariadb
   vars:
-      hostname_node0: "{{ hostvars[groups['mariadb'][0]]['ansible_hostname'] }}"
-      hostname_node1: "{{ hostvars[groups['mariadb'][1]]['ansible_hostname'] }}"
-      hostname_node2: "{{ hostvars[groups['mariadb'][2]]['ansible_hostname'] }}"
-      ip_node0: "hostvars[groups['databases'][0]]['listen_ip'] | default(hostvars[groups['databases'][0]]['ansible_default_ipv4']['address'])"
-      ip_node1: "hostvars[groups['databases'][1]]['listen_ip'] | default(hostvars[groups['databases'][1]]['ansible_default_ipv4']['address'])"
-      ip_node2: "hostvars[groups['databases'][2]]['listen_ip'] | default(hostvars[groups['databases'][2]]['ansible_default_ipv4']['address'])"
+      hostname_node0: "{{ hostvars[groups['databases'][0]]['ansible_hostname'] }}"
+      hostname_node1: "{{ hostvars[groups['databases'][1]]['ansible_hostname'] }}"
+      hostname_node2: "{{ hostvars[groups['databases'][2]]['ansible_hostname'] }}"
+      ip_node0: "{{ hostvars[groups['databases'][0]]['listen_ip'] | default(hostvars[groups['databases'][0]]['ansible_default_ipv4']['address']) }}"
+      ip_node1: "{{ hostvars[groups['databases'][1]]['listen_ip'] | default(hostvars[groups['databases'][1]]['ansible_default_ipv4']['address']) }}"
+      ip_node2: "{{ hostvars[groups['databases'][2]]['listen_ip'] | default(hostvars[groups['databases'][2]]['ansible_default_ipv4']['address']) }}"

roles/mariadb/files/galera.cnf

@@ -0,0 +1,20 @@
+[mysqld]
+binlog_format=ROW
+default-storage-engine=innodb
+innodb_autoinc_lock_mode=2
+bind-address=0.0.0.0
+
+# Galera Provider Configuration
+wsrep_on=ON
+wsrep_provider=/usr/lib/galera/libgalera_smm.so
+
+# Galera Cluster Configuration
+wsrep_cluster_name="test_cluster"
+wsrep_cluster_address="gcomm://{{ ip_node0 }},{{ ip_node1 }},{{ ip_node2 }}"
+
+# Galera Synchronization Configuration
+wsrep_sst_method=rsync
+
+# Galera Node Configuration
+wsrep_node_address="{{ listen_ip | default(ansible_default_ipv4.address) }}"
+wsrep_node_name="{{ ansible_nodename }}"

roles/mariadb/tasks/main.yml

@@ -13,9 +13,6 @@
     owner: root
     group: root
 
-- name: start service at boot.
-  command: systemctl reenable mysql.service
-
 - name: make mariadb settings volume
   file:
     path: "{{ item }}"
@@ -24,30 +21,35 @@
   with_items:
       - /srv/mariadb/lib/mysql
       - /srv/mariadb/etc/mysql
+      - /srv/mariadb/etc/mysql/conf.d
 
 - name: place settings file
   copy:
     src: files/my.cnf
-    dest: /srv/mariadb/etc/mysql
+    dest: /srv/mariadb/etc/mysql/conf.d/my.cnf
     mode: 660
 
-- name: Set galara.cnf on first node if we have at least three nodes.
-  copy:
-    src: files/galera-master.cnf
+- name: Set galara.cnf on node if we have at least three nodes.
+  template:
+    src: files/galera.cnf
     dest: /srv/mariadb/etc/mysql/conf.d/galera.cnf
     mode: 660
-  when: ansible_nodename == hostname_node0 and hostvars[groups['mariadb']]|length >= 3
-
-- name: Set galara.cnf on other nodes if we have at least three nodes.
-  copy:
-    src: files/galera-slave.cnf
-    dest: /srv/mariadb/etc/mysql/conf.d/galera.cnf
-    mode: 660
-  when: ansible_nodename != hostname_node0 and hostvars[groups['mariadb']]|length >= 3
+  when: groups['databases'] | length >= 3
 
 - command: systemctl daemon-reload
 
+- name: start service at boot.
+  command: systemctl reenable mysql.service
+
+# This mimics galera_new_cluster.sh
+- name: Initialize a new cluster.
+  command: systemctl set-environment _WSREP_NEW_CLUSTER='--wsrep-new-cluster'
+  when: groups['databases'] | length >= 3 and ansible_hostname == hostname_node0
+
 - name: make sure service is started
   systemd:
     name: mysql.service
     state: started
+
+- name: Prevent cluster re-initialization
+  command: systemctl set-environment _WSREP_NEW_CLUSTER=''

roles/mariadb/templates/mysql.service

@@ -9,10 +9,12 @@ Restart=always
 ExecStartPre=-/usr/bin/docker kill %n || /bin/true
 ExecStartPre=-/usr/bin/docker rm %n
 ExecStartPre=/usr/bin/docker pull mariadb:10.2
-ExecStart=/usr/bin/docker run  -p 3306:3306 --name %n \
+ExecStart=/usr/bin/docker run --name %n \
+ -p 3306:3306 -p 4567:4567 -p 4568:4568 -p 4444:4444 \
  -v /srv/mariadb/lib/mysql:/var/lib/mysql \
- -v /srv/mariadb/etc/mysql:/etc/mysql \
- -e MYSQL_ROOT_PASSWORD={{ secrets['MYSQL_ROOT_PASSWORD'] }} mariadb:10.2
+ -v /srv/mariadb/etc/mysql/conf.d:/etc/mysql/conf.d \
+ -e MYSQL_ROOT_PASSWORD={{ secrets['MYSQL_ROOT_PASSWORD'] }} mariadb:10.2 \
+ ${MYSQLD_OPTS} ${_WSREP_NEW_CLUSTER} ${_WSREP_START_POSITION}
 
 [Install]
 WantedBy=multi-user.target

secrets.yml

@@ -1,30 +1,30 @@
 $ANSIBLE_VAULT;1.1;AES256
-62633134346438356462333363626164393762356139653666323461333037393536373631653565
-6631306631333538353534663738313062636232633339610a303161323131373739393735666463
-65353135626430353737373239623361306137326334333761626235353463393465383830666666
-6138616530346563310a306263316331346263356139383435316239346230313266636363313564
-36633130393062373936363765636361343939313639326237633337353665666338633338343837
-34613534333063303537323738396436333964613362636664366264313334663365336132623464
-64656131373261376466356638636338643135393139386534626132323262393064626666323462
-64323664373262356632393465653932303939313338656665336639613966626234636666373163
-35633231666338643863623737396435626364333365656536613130666435323837323136663339
-61363936336434656530313538643463663737613831646265313731363734356635356438353062
-34323063346265393737343834343065616139656234666230323131366138396265393737666236
-39353766643239323339623534393962666432656331323462656439306365613539366230643133
-36316138303361313134336431343137343433383430616137376563383233303432383664333930
-61613531313638303531643232343066376565663032326533313461363839383664366338356439
-37363233666663653736376538386536653262653633323065363830623032363063393635653762
-32636365656362323362303962306538336234626533323830656230386432666461343063663832
-62373133343933353563653762333836333862376232353339313662363865616439623635393839
-37346433346264633036343761613230396434366132653261643137386466326235613030306235
-34333065623232303939623233373762393939653639333734336336303762326662386530356563
-65303165623564303635356337353662363433626466653939323438633938386166386262623435
-64376431396631623034386434393431616631363663393835343035313639663538643565616330
-65353365303131326335646164333231306564383936396139643935646331393235326666336230
-38326165663865343966356335326438303133663239656235313935626332323332376665343132
-62336139643262333938303537313533623535333736643163373137343035393034613939663061
-36323063643734343865333138356434643266663436653435353132386330636238343637653434
-65616361333263336332643262623034343439383737366663373166643433653466313237613930
-32373162646461323266353662326134343839613264313339306430366165633838663831666565
-65333337623962313561306333616232393334353934316565666331336561633934623339353138
-62656339386530333036383831613762353234643461656436623033613930353531
+35643437313834633532373265366630663035336231306639623561613765386332663334343237
+3339363162303463353437326331656532336138373066620a623137643762383532376361353364
+37646236386466353636396535376463333133323664316634663466663164303063383830653039
+3535666361303562630a316137376531636537383138663662373865383431343035646539356137
+38323866643831353537366630363333663865383261633938346664633362343661343839383766
+66363733356333303334323136376136353738376362376231353338343763663131363731343639
+61383138626235633663666430383964616239363035663663646133636434363032626633663865
+30663732646630393163653461626435333463396463333236313930346461626364626166386365
+66323736316230376165666366363136666533376335316132343361393532616536383965363339
+30376362356665633630393561653532613139366236663961643864383738353430666562623730
+34663166393665653265663836623731386235633062306562373935633737363639383336303539
+37663763623664623038316438356138363134646230643261646262353163333430616462393866
+31666233636233356464633436626637313633623736343264613037353432386131393964386663
+36353236613662633764366437306461316138366461653731373436613039346663663536653362
+38656636303935626563303732666261373665303035333661643865393166653330646336393961
+31646539396131626464313733383638656438613530663166393035343630353764313232323432
+34386334666231323261343765623636313032373835396332623037613866613636393038653266
+36336531356534633933383432646663663364376130386239613836336263623161326563346661
+33636232313866613662353661373533383138393434396338343934326333326238336638396462
+65376133343038313437343934373265333632663133653133656130636533663237623839623634
+35363764363763363465363437623964363362616261663166633066373033633864336532633031
+32323733616562663031303230383561373637326436336462363461313532623262653866323862
+34643631333533626537373538353564306261313035303530666462326534633638363932363037
+65336230373034643966656561303164373463353638316632613431643535303930373334383134
+38323731363535313065326330653666323934636466386238616664316635303333653631396639
+39303737613361653862343964303231393164346134633366633262326230643137303331373231
+31323832363937663935333737613133323265323863623933633962633230386339636432643937
+66653763376663666637353738646565343835333937343765356539383734316231623466343634
+30663135663938393561333133663737653635393432333534306466366332333338