#!/bin/bash
# forksand-mariadb-setup
#
# Script template for setting up MySQL compatible MariaDB Cluster
# on four nodes: sql1 sql2 sql3 sql4
#
# https://mariadb.com/kb/en/library/getting-started-with-mariadb-galera-cluster/
# 
# Get repo mirror:
# https://downloads.mariadb.org/mariadb/repositories

exit 0

# As root
apt-get install software-properties-common dirmngr
apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 0xF1656F24C74CD1D8
add-apt-repository 'deb [arch=amd64] http://sfo1.mirrors.digitalocean.com/mariadb/repo/10.3/debian stretch main'
apt-get update
apt-get install mariadb-server
apt-get clean

# Set config like here:
# https://mariadb.org/installing-mariadb-galera-cluster-on-debian-ubuntu/
# /etc/mysql/my.cnf
# =================================================
[galera]
# Mandatory settings
wsrep_on=ON
wsrep_provider=/usr/lib/galera/libgalera_smm.so
wsrep_cluster_address="gcomm://10.42.1.171,10.42.1.172,10.42.1.173,10.42.1.174"
wsrep_cluster_name="XXX"
binlog_format=row
default_storage_engine=InnoDB
innodb_autoinc_lock_mode=2
wsrep_sst_method=rsync
query_cache_size=0
query_cache_type=0
#
# Allow server to accept connections on all interfaces.
#
bind-address=10.42.1.174
#
# Optional setting
#wsrep_slave_threads=1
#innodb_flush_log_at_trx_commit=0

# =================================================

service mysql stop
# on just sql1:
galera_new_cluster

# See if the cluster node comes up:
mysql -p -u root -e 'SELECT VARIABLE_VALUE as "cluster size" FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME="wsrep_cluster_size"'

# Start another node, sql2:
service mysql start

# See if it came up:
mysql -p -u root -e 'SELECT VARIABLE_VALUE as "cluster size" FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME="wsrep_cluster_size"'

# Then do sql3 sql4
service mysql start

# See if it came up:
mysql -p -u root -e 'SELECT VARIABLE_VALUE as "cluster size" FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME="wsrep_cluster_size"'

###############################################
# run this to lock down:
mysql_secure_installation


###########################################
# If all cluster nodes get shutdown at the same time, the cluster needs to be boot strapped again.
# On just one node, the most advanced, if known (e.g. sql1):
galera_new_cluster

# On other nodes sql2 sql3 sql4
service mysql start

# Maybe need on most advanced node:
# sed -i -e 's/safe_to_bootstrap: 0/safe_to_bootstrap: 1/g' /var/lib/mysql/grastate.dat