4.2. Install MariaDBΒΆ

We will use MariaDB as the main SQL database.

Run the following command to create a data container:

docker run -v /var/lib/mysql --name dbdata busybox /bin/true

The default MariaDB configuration may not be suitable for the server hardware, thus we may want to use a different configuration file. There are official templates for 5 different sizes of hardware resource: small, medium, large, huge, innodb-heavy-4G. The criteria to choose any of them are written in the comments of these template configuration files. For convenience, the relevant part in the comments are copied and pasted below:

  • small: This is for a system with little memory (<= 64M) where MariaDB is only used from time to time and it is important that the mysqld daemon does not use much resources.
  • medium: This is for a system with little memory (32M - 64M) where MariaDB plays an important part, or systems up to 128M where MariaDB is used together with other programs (such as a web server).
  • large: This is for a large system with memory = 512M where the system runs mainly MariaDB.
  • huge: This is for a large system with memory of 1G-2G where the system runs mainly MariaDB.
  • innodb-heavy-4G: This is for systems with 4GB of memory running mostly MariaDB using InnoDB only tables and performing complex queries with few connections.

Very likely small is not enough for our use case, as many of the Internet apps that we will install probably uses MariaDB as an important part. You can start with medium if you are not sure how much resource your MairaDB instance would use.

Run the following commands to download and do some preprocessing of the MariaDB configuration files, where CONF_SIZE should be replaced with one of small, medium, large, huge or innodb-heavy-4G:

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export SIZE=CONF_SIZE
sudo mkdir $DOCKER_SHARE/mariadb
sudo -E wget -O $DOCKER_SHARE/mariadb/my.cnf \
 https://github.com/MariaDB/server/raw/10.1/support-files/my-$SIZE.cnf.sh
sudo sed -ri -e 's/^(bind-address|skip-networking|socket)/#\1/' \
 -e 's/@MYSQL_TCP_PORT@/3306/' \
 -e 's/^#(innodb_buffer_pool_size|innodb_log_file_size|innodb_log_buffer_size)/\1/' \
 -e '/^\[mysqld\]/a \
user\t\t= mysql\
character-set-server = utf8 \
collation-server = utf8_general_ci' \
 -e '/^\[client\]/a \
default-character-set = utf8' $DOCKER_SHARE/mariadb/my.cnf
sudo -s <<EOF
echo >> $DOCKER_SHARE/mariadb/my.cnf
echo '!includedir /etc/mysql/conf.d/' >> $DOCKER_SHARE/mariadb/my.cnf
EOF
unset SIZE

Explanation:

  • line 5: do not set bind-address, skip-networking, or socket;
  • line 6: use 3306 as the MariaDB listening port;
  • line 7: enable some innodb relevant options;
  • line 8-13: run MariaDB as user “mysql” and use UTF-8 encoding.

Optionally we can also adjust other parameters in the config file at this point:

sudo $EDITOR $DOCKER_SHARE/mariadb/my.cnf

Start the MariaDB container using the following command, after replacing 'PASSWORD' with the MariaDB root user password that you want to use:

docker run --restart always -d --volumes-from dbdata \
 -v $DOCKER_SHARE/mariadb/my.cnf:/etc/mysql/my.cnf:ro \
 -e MYSQL_ROOT_PASSWORD='PASSWORD' --dns $HOST_ADDR \
 --name mariadb mariadb:10.1

Since our command line history has recorded the root password of MariaDB, we need to clear the relevant history entries:

history -a
sed -i '/MYSQL_ROOT_PASSWORD/d' ~/.bash_history

The commands above first write all histories in RAM to the history file, then delete all history entries which contains MYSQL_ROOT_PASSWORD.

We then need to disable remote root access of the MariaDB instance for better security. enter the MariaDB container shell:

ne mariadb

Inside the shell of the MariaDB container, run the following command to start MariaDB shell:

mysql -u root -p

Execute the following SQL statement:

rename user 'root'@'%' to 'root'@'localhost';

The SQL statement above limits root access to localhost only.

Press Ctrl-D twice to exit the MariaDB shell and the container’s shell.

Finally, add a DNS record to specify db as an alias of mariadb and restart dnsmasq:

sudo -s <<< "echo 'cname=db,mariadb' > /etc/dnsmasq.d/db"
sudo systemctl restart dnsmasq