Create a MariaDB service on CentOS with Docker

Learning Docker for a long time, this is my first time to create a service with it. In Docker’s concept, each service should have a container, and your application may comes with many containers.

This time, I am gonna create a MariaDB service.

First of all, let’s create a file named Dockerfile. Dockerfile is used to build an image:
```
 FROM centos:latest
 MAINTAINER David Xie "david.scriptfan@gmail.com"

 EXPOSE 3306
```

With this file, we can get a clean CentOS image, but we don’t have MariaDB installed. MariaDB in CentOS’s repo is not the latest, we can install it from MariaDB’s official repo. This is easy, just create a repo file and put it /etc/yum.repos.d/. Our Dockerfile will look like this:

 FROM centos:latest
 MAINTAINER David Xie "david.scriptfan@gmail.com"

 ADD mariadb.repo /etc/yum.repos.d/mariadb.repo

 RUN yum install -y hostname MariaDB-server
 RUN yum clean all

 EXPOSE 3306

And mariadb.repo:

 [mariadb]
 name = MariaDB
 baseurl = http://yum.mariadb.org/10.0/centos6-amd64
 gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB
 gpgcheck=1

Now we have MariaDB installed, but how can I connect to it, and how to set password for root? Let’s add more files for it.

server.cnf is used to make sure we are not blocked by MariaDB:

 [mysqld]
 bind-address=0.0.0.0
 console=1
 general_log=1
 general_log_file=/dev/stdout
 log_error=/dev/stderr
 collation-server=utf8_unicode_ci
 character-set-server=utf8

mariadb.sql is used to update password for root to root and grant all privilliges to all IPs.

 USE mysql;
 GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' WITH GRANT OPTION;
 FLUSH PRIVILEGES;
 UPDATE user SET password=PASSWORD("root") WHERE user='root';
 FLUSH PRIVILEGES;

mariadb.sh is used to apply all updates and start MariaDB service for us:

 #!/bin/sh
 chown -R mysql:mysql /var/lib/mysql
 mysql_install_db --user mysql > /dev/null

 mysqld_safe --user mysql &

 sleep 5s

 mysql -v < /root/mariadb.sql

 sleep 5s

 ps -wef | grep mysql | grep -v grep | awk '{print $2}' | xargs kill -9

 mysqld_safe --user mysql

Final thing, we need to update our Dockerfile:

 # application container for MySQL
 # VERSION 2014-07-14

 FROM centos:latest
 MAINTAINER David Xie "david.scriptfan@gmail.com"

 ADD mariadb.repo /etc/yum.repos.d/mariadb.repo
 ADD mariadb.sql /root/mariadb.sql
 ADD server.cnf /etc/my.cnf.d/server.cnf
 ADD mariadb.sh /root/mariadb.sh

 RUN yum install -y hostname MariaDB-server
 RUN yum clean all
 RUN chmod +x /root/mariadb.sh

 EXPOSE 3306

 CMD ["/root/mariadb.sh"]

We already have everything we need, we can create our container now.
```
 docker build --rm=true --no-cache=true -t mariadb .
 docker run -d -p 3306:3306 mariadb
```
After 10s, our container is ready to use. If you are using Docker on boot2docker, use boot2docker ip to get correct IP for it. Then you can connect your mariadb with IP:3306.

This project is on github, please visit: mariadb. If anything is wrong here, please let me know.