/docker-rpi-mysql

Docker MySQL image for Raspberry Pi

Primary LanguageShell

docker-rpi-mysql

Base docker image to run a MySQL database server. Based on tutum docker mysql image.

Usage

To create the image dordoka/rpi-mysql, execute the following command on the docker-rpi-mysql folder:

    docker build -t dordoka/rpi-mysql 

To run the image and bind to port 3306:

    docker run -d -p 3306:3306 dordoka/rpi-mysql

The first time that you run your container, a new user admin with all privileges will be created in MySQL with a random password. To get the password, check the logs of the container by running:

    docker logs <CONTAINER_ID>

You will see an output like the following:

    ========================================================================
    You can now connect to this MySQL Server using:

        mysql -uadmin -p47nnf4FweaKu -h<host> -P<port>

    Please remember to change the above password as soon as possible!
    MySQL user 'root' has no password but only allows local connections.
    ========================================================================

In this case, 47nnf4FweaKu is the password allocated to the admin user.

Remember that the root user has no password, but it's only accessible from within the container.

You can now test your deployment:

    mysql -uadmin -p

Done!

Setting a specific password for the admin account

If you want to use a preset password instead of a random generated one, you can set the environment variable MYSQL_PASS to your specific password when running the container:

    docker run -d -p 3306:3306 -e MYSQL_PASS="mypass" dordoka/rpi-mysql

You can now test your deployment:

    mysql -uadmin -p"mypass"

The admin username can also be set via the MYSQL_USER environment variable.

Mounting the database file volume

In order to persist the database data, you can mount a local folder from the host on the container to store the database files. To do so:

    docker run -d -v /path/in/host:/var/lib/mysql dordoka/rpi-mysql /bin/bash -c "/usr/bin/mysql_install_db"

This will mount the local folder /path/in/host inside the docker in /var/lib/mysql (where MySQL will store the database files by default). mysql_install_db creates the initial database structure.

Remember that this will mean that your host must have /path/in/host available when you run your docker image!

After this you can start your MySQL image, but this time using /path/in/host as the database folder:

    docker run -d -p 3306:3306 -v /path/in/host:/var/lib/mysql dordoka/rpi-mysql

Mounting the database file volume from other containers

Another way to persist the database data is to store database files in another container. To do so, first create a container that holds database files:

docker run -d -v /var/lib/mysql --name db_vol -p 22:22 resin/rpi-raspbian:jessie 

This will create a new ssh-enabled container and use its folder /var/lib/mysql to store MySQL database files. You can specify any name of the container by using --name option, which will be used in next step.

After this you can start your MySQL image using volumes in the container created above (put the name of container in --volumes-from)

docker run -d --volumes-from db_vol -p 3306:3306 dordoka/rpi-mysql 

Migrating an existing MySQL Server

In order to migrate your current MySQL server, perform the following commands from your current server:

To dump your databases structure:

    mysqldump -u<user> -p --opt -d -B <database name(s)> > /tmp/dbserver_schema.sql

To dump your database data:

    mysqldump -u<user> -p --quick --single-transaction -t -n -B <database name(s)> > /tmp/dbserver_data.sql

To import a SQL backup which is stored for example in the folder /tmp in the host, run the following:

    sudo docker run -d -v /tmp:/tmp dordoka/rpi-mysql /bin/bash -c "/import_sql.sh <user> <pass> /tmp/<dump.sql>"

Also, you can start the new database initializing it with the SQL file:

    sudo docker run -d -v /path/in/host:/var/lib/mysql -e STARTUP_SQL="/tmp/<dump.sql>" dordoka/rpi-mysql

Where <user> and <pass> are the database username and password set earlier and <dump.sql> is the name of the SQL file to be imported.

Replication - Master/Slave

To use MySQL replication, please set environment variable REPLICATION_MASTER/REPLICATION_SLAVE to true. Also, on master side, you may want to specify REPLICATION_USER and REPLICATION_PASS for the account to perform replication, the default value is replica:replica

Examples:

  • Master MySQL

  •   docker run -d -e REPLICATION_MASTER=true -e REPLICATION_PASS=mypass -p 3306:3306 --name mysql dordoka/rpi-mysql
    
  • Example on Slave MySQL:

  •   docker run -d -e REPLICATION_SLAVE=true -p 3307:3306 --link mysql:mysql dordoka/rpi-mysql
    

Now you can access port 3306 and 3307 for the master/slave MySQL.

Environment variables

MYSQL_USER: Set a specific username for the admin account (default 'admin').

MYSQL_PASS: Set a specific password for the admin account.

STARTUP_SQL: Defines one or more SQL scripts separated by spaces to initialize the database. Note that the scripts must be inside the container, so you may need to mount them.

Kudos

To Tutum, for the docker mysql image. To Hypriot, for the awesome raspbian based distro that includes docker.