MySQL 5.7 second instance using systemd and SELinux

sudo vim /etc/my.cnf

# =================== Second instance ====================
[mysqld@inst2]
user            = mysql
pid-file        = /var/run/mysqld/mysqld-inst2.pid
socket          = /var/lib/mysql-inst2/mysql-inst2.sock
port            = 3307
datadir         = /var/lib/mysql-inst2
log-error       = /var/log/mysqld-inst2.log

cd /var/lib/
mkdir mysql-inst2

yum install policycoreutils-python-2.2.5-20.el7.x86_64

semanage port -a -t mysqld_port_t -p tcp 3307
chown -R mysql.mysql /var/lib/mysql-inst2
restorecon -R /var/lib/mysql-inst2
chcon -Rt mysqld_db_t /var/lib/mysql-inst2/
chcon -Ru system_u /var/lib/mysql-inst2/

Credits1, Credits2

systemctl start mysqld@inst2