Ansible Galera (Ready for OpenStack)

This module helps set up a Galera cluster.

It will add two repositories:

• MariaDB (includes MariaDB and Galera)
• Percona (includes xtrabackup)

Supported operating systems:

• CentOS 7.x
• RedHat EL 7.x
• Debian 8.x

Key features:

• Firewalld (you need the iptables and firewalld packages on the server)
• SELinux
• Pacemaker

Pacemaker support includes a tool called clustercheck and the necessary setup for xinetd.

If Pacemaker is enabled, the Galera cluster will stop, and the wsrep_cluster_address setting in the MariaDB configuration will be removed, allowing Pacemaker to manage things.

Requirements

You need at least 3 nodes and Ansible 2.0 to use this module.

Role Variables

Be cautious! If galera_reset_cluster is set to true, all databases will be erased.

CONFIG

### MARIADB
master: ctrl01
mariadb_bind_address: 0.0.0.0
mariadb_port: 3306
mariadb_max_connections: 4096
mariadb_query_cache_size: 0
mariadb_default_storage_engine: InnoDB
mariadb_maintenance_password: I3uL6AqJLHInv85x
mariadb_root_password: 3248ew7dsYUG762
mariadb_hosts_allow: 192.168.%
mariadb_datadir: /var/lib/mysql

### GALERA
galera_node_address: "{{ ansible_eth0.ipv4.address }}"
galera_pacemaker_support: false
galera_clustercheck_user: clustercheck
galera_clustercheck_password: Y3aH1l0ved2CH3CK
galera_reset_cluster: false
galera_selinux: true
galera_firewalld: true
galera_cluster_name: uoi-sql-cluster
galera_sst_method: xtrabackup-v2
galera_sst_user: sst-replication
galera_sst_password: gr34tp4ss0rd
galera_cluster_nodes:
  - ctrl01
  - ctrl02
  - ctrl03
galera_provider_options: 'pc.ignore_quorum=true; gcache.size=1G'
galera_retry_autocommit: 10
galera_slave_threads: 8

VARIABLES

Since this module supports both RedHat and Debian systems, some values need to be defined based on the OS type.

### REDHAT
# file: roles/galera/vars/RedHat.yml
galera_packages:
  - MariaDB-server
  - percona-xtrabackup
  - socat
  - MySQL-python
  - percona-toolkit
  - galera
  - policycoreutils-python
  - checkpolicy
  - xinetd
mariadb_svc_name: mariadb
mariadb_config: my.cnf.d/server.cnf
galera_provider: /usr/lib64/galera/libgalera_smm.so
percona_package: https://www.percona.com/redir/downloads/percona-release/redhat/latest/percona-release-0.1-3.noarch.rpm

### DEBIAN
# file: roles/galera/vars/Debian.yml
galera_packages:
  - mariadb-server
  - xtrabackup
  - socat
  - python-mysqldb
  - percona-toolkit
  - xinetd
mariadb_svc_name: mysql
mariadb_config: mysql/conf.d/galera.cnf
galera_provider: /usr/lib/galera/libgalera_smm.so

## MAIN
# file: roles/galera/vars/main.yml
galera_xinet_port: 9200

# FIREWALL PORTS
fw_mysql: "{{ mariadb_port }}"
fw_mysql_ist: 4568
fw_mysql_sst: 4444
fw_galera: 4567
fw_xinetd: "{{ galera_xinet_port }}"

Dependencies

None.

Example Playbook

master: node1
mariadb_bind_address: 0.0.0.0
mariadb_max_connections: 4096
mariadb_maintenance_password: I3uL6AqJLHInv85x
mariadb_root_password: 3248ew7dsYUG762
mariadb_hosts_allow: 10.0.%

galera_node_address: "{{ ansible_eth0.ipv4.address }}"
galera_pacemaker_support: false
galera_clustercheck_user: clustercheck
galera_clustercheck_password: Y3aH1l0ved2CH3CK
galera_cluster_name: uoi-sql-cluster
galera_sst_password: gr34tp4ss0rd
galera_cluster_nodes:
  - node-1
  - node-2
  - node-3
  - node-4
  - node-5

galera-status

After setting up, run the command galera-status to check the status of the Galera cluster.

# galera-status

License

Apache

Author Information

This role was created in 2016 by Gaëtan Trellu (goldyfruit).