Add HAProxy check user to prevent `max_connect_error` exceptions

playbooks/roles/haproxy/defaults/main.yml

@@ -63,7 +63,7 @@ haproxy_applications:
     balance roundrobin
     option  tcplog
     option  tcpka
-    option mysql-check
+    option mysql-check user haproxy
     server  galera1 192.168.33.100:3306 check weight 1
     server  galera2 192.168.33.110:3306 check weight 1
     server  galera3 192.168.33.120:3306 check weight 1

playbooks/roles/mariadb/defaults/main.yml

@@ -19,6 +19,13 @@ MARIADB_CLUSTERED: no
 MARIADB_CLUSTER_USER_ADMIN: "mariadb_clu_root"
 MARIADB_CLUSTER_PASSWORD_ADMIN: "password"
 MARIADB_HOST_PRIV: '%'
+
+MARIADB_HAPROXY_USER: 'haproxy'
+MARIADB_HAPROXY_HOSTS: 
+  - '192.168.33.100'
+  - '192.168.33.110'
+  - '192.168.33.120'
+
 MARIADB_LISTEN_ALL: false
 
 MARIADB_DATABASES:

playbooks/roles/mariadb/tasks/cluster.yml

@@ -48,4 +48,11 @@
   when: not mariadb_bootstrap.stat.exists
 
 - name: touch bootstrap file to confirm we are fully up
-  file: path="/etc/mysql/ansible_cluster_started" state=touch
\ No newline at end of file
+  file: path="/etc/mysql/ansible_cluster_started" state=touch
+
+# This is needed for mysql-check in haproxy or other mysql monitor
+# scripts to prevent haproxy checks exceeding `max_connect_errors`.
+- name: create haproxy monitor user
+  command: >
+    mysql -e "INSERT INTO mysql.user (Host,User) values ('{{ item }}','{{ MARIADB_HAPROXY_USER }}'); FLUSH PRIVILEGES;"
+  with_items: MARIADB_HAPROXY_HOSTS