Introduction

  • mariadb/mysql spits on port 3306
  • based on upstream image tagged latest
  • re-run without troubles (just keep the volume)
  • shared accross different applications

Fetch / Update the official image

Fetch or update the MariaDB image and check,

docker pull mariadb:latest
docker images

Launch the container

Make sure the data folder doesn't exist yet otherwise the init part that follows doesn't make sense,

app=mariadbprod
sudo ls -alhF /data/$app/
#sudo rm -rf /data/$app/

Generate a strong password that you would copy/paste to replace PASSWORD_HERE and USERPASS_HERE,

#sudo apt install pwgen (Ubuntu)
sudo yum install pwgen (CentOS/RHEL EPEL needed)
pwgen

and write it someplace so you don't loose it.

Launch a MariaDB container mapping volume /data/mariadbprod/ to /var/lib/mysql/ and check.

app=mariadbprod
docker ps -a | grep $app
docker run -d --name $app -h $app \
    -p 3306:3306 \
    -v /data/$app:/var/lib/mysql \
    -e MYSQL_ROOT_PASSWORD=PASSWORD_HERE \
    mariadb
docker ps -a | grep $app
docker logs $app
  • Note. this is for the first run. For subsequents runs, remove -e MYSQL_ROOT_PASSWORD=PASSWORD_HERE.
  • Note. -p 3306:3306 to allow access from the docker host or the network. Otherwise the db will only be used by other containers tru run --link which is good but prevents troubleshooting from the docker host or network. Also note that it depends on the MariaDB setup itself if you want to listen on the network (defaults to localhost only), so it's almost safe to map that port to the docker host. I would recomend it.

  • Note. no need to tweak the my.cnf to allow remote connections unless you want to access the db from the docker host or from the network. Basically we are using localhost's binding which is enabled by default. However, if you need to, here's how to tweak it if needed,

    app=mariadbprod docker exec -ti $app bash apt -y update apt -y install vim export TERM=xterm cp -pi /etc/mysql/my.cnf /etc/mysql/my.cnf.dist vi /etc/mysql/my.cnf

Setup some database

Setup the database e.g 'somedb',

app=mariadbprod
docker exec -ti $app mysql -uroot -pPASSWORD_HERE

create database somedb;
grant all privileges on somdb.* to somedbuser identified by 'USERPASS_HERE';
flush privileges;

eventually inject some shit into it,

app=mariadbprod
docker exec -ti $app mysql -usomedbuser -pUSERPASS_HERE somedb < ~/schema.sql

and check,

app=mariadbprod
docker exec -ti $app mysql -usomedbuser -pUSERPASS_HERE somedb
show databases;
use somedb;
show tables;
^D

Network Access

Check that you can access that DB from another container. Note. connecting to host defined by the --link :alias (here mariadb).

app=tmpcheckmaria
docker run -ti --name $app -h $app --link mariadbprod:mariadb custom/ubuntu bash
cat /etc/hosts
ping -c1 mariadb
nc -z -v mariadb 3306
apt -y update && apt -y install mariadb-client
mysql -uroot -pPASSWORD_HERE -h mariadb
show databases;
use somedb;
show tables;
^D
  • Note. custom/ubuntu already contains the ping & netcat packages
  • Note. if you cannot reach the mariadb database, try with --protocol=TCP.

Maintenance / Operations

Operating Docker Containers

References

Alt References about SQlite & enhancements