Table of Contents

• Installation
• Quick Start
• Command-line arguments
• Setting a specific password for the admin account
• Creating Database at Launch
• Persistence
• Backuping
• Checking backup
• Restore from backup
• Replication - Master/Slave
• Environment variables
• Logging
• Out of the box

Installation

• Install Docker 1.9+ or askubuntu
• Pull the latest version of the image.

docker pull romeoz/docker-mysql

Alternately you can build the image yourself.

git clone https://github.com/romeoz/docker-mysql.git
cd docker-mysql
docker build -t="$USER/mysql" .

Quick Start

Run the mysql container:

docker run --name mysql -d romeoz/docker-mysql

The simplest way to login to the mysql container is to use the docker exec command to attach a new process to the running container and connect to the MySQL Server over the unix socket.

docker exec -it mysql mysql -uroot

Command-line arguments

You can customize the launch command of mysql by specifying arguments to mysqld on the docker run command. For example, to run mysql using lower case table name, you can do:

docker run --name db -d \
  romeoz/docker-mysql \
  --lower_case_table_names=1

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 --name db -d -e 'MYSQL_PASS=mypass' romeoz/docker-mysql

You can now test your deployment:

docker exec -it db mysql -uadmin -pmypass

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

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

Creating Database at Launch

If you want a database to be created inside the container when you start it up for the first time you can set the environment variable DB_NAME to a string that names the database.

docker run --name mysql -d  -e 'DB_NAME=dbname' romeoz/docker-mysql

You may also specify a comma separated list of database names in the DB_NAME variable. The following command creates two new databases named dbname1 and dbname2 (p.s. this feature is only available in releases greater than 9.1-1).

docker run --name mysql -d \
  -e 'DB_NAME=dbname1,dbname2' \
  romeoz/docker-mysql

If this is combined with importing SQL files, those files will be imported into the created database.

Persistence

For data persistence a volume should be mounted at /var/lib/mysql.

SELinux users are also required to change the security context of the mount point so that it plays nicely with selinux.

mkdir -p /to/path/data
sudo chcon -Rt svirt_sandbox_file_t /to/path/data

The updated run command looks like this.

docker run --name mysql -d \
  -v /host/to/path/data:/var/lib/mysql \
  romeoz/docker-mysql

This will make sure that the data stored in the database is not lost when the container is stopped and started again.

Backuping

The backup all databases is made over a regular MySQL connection (used mysqldump).

Create a temporary container for backup:

docker run -it --rm \
    --net mysql_net \
    -e 'MYSQL_MODE=backup' \
    -e 'DB_REMOTE_HOST=mysql' -e 'DB_REMOTE_USER=admin' -e 'DB_REMOTE_PASS=pass' \
    -v /host/to/path/backup:/tmp/backup \
    romeoz/docker-mysql

Archive will be available in the /host/to/path/backup.

Algorithm: one backup per week (total 4), one backup per month (total 12) and the last backup. Example: backup.last.tar.bz2, backup.1.tar.bz2 and /backup.dec.tar.bz2.

To pass additional settings to mysqldump, you can use command-line arguments:

docker run -it --rm \
    --net mysql_net \
    -e 'MYSQL_MODE=backup' \    
    -e 'DB_REMOTE_HOST=mysql' -e 'DB_REMOTE_USER=admin' -e 'DB_REMOTE_PASS=pass' \
    -v /host/to/path/backup:/tmp/backup \    
    romeoz/docker-mysql \
    --master-data --single-transaction

Checking backup

Check-data is the name of database DB_NAME.

docker run -it --rm \
    -e 'MYSQL_CHECK=default' \
    -e 'DB_NAME=foo' \
    -v /host/to/path/backup:/tmp/backup \
    romeoz/docker-mysql

Default used the /tmp/backup/backup.last.bz2.

Restore from backup

docker run --name='db_restore' -d \
  -e 'MYSQL_RESTORE=default' \
  -v /host/to/path/backup:/tmp/backup \
  romeoz/docker-mysql

Also see "Replication".

Replication - Master/Slave

You may use the MYSQL_MODE variable along with REPLICATION_HOST, REPLICATION_PORT, REPLICATION_USER and REPLICATION_PASS to enable replication.

Your master database must support replication or super-user access for the credentials you specify. The MYSQL_MODE variable should be set to master, for replication on your master node and slave for replication or a point-in-time snapshot of a running instance.

Create a master instance with database dbname

docker network create mysql_net

docker run --name='mysql-master' -d \
  -e 'MYSQL_MODE=master' \
  -e 'DB_NAME=dbname' \
  -e 'MYSQL_USER=dbuser' -e 'MYSQL_PASS=dbpass' \
  romeoz/docker-mysql

or import backup

docker network create mysql_net

docker run --name='mysql-master' -d \
  -e 'MYSQL_MODE=master' \
  -e 'MYSQL_RESTORE=/tmp/backup/backup.last.bz2' \
  -e 'MYSQL_USER=dbuser' -e 'MYSQL_PASS=dbpass' \
  -v /host/to/path/backup:/tmp/backup \
  romeoz/docker-mysql

Create a slave instance + fast import backup from master

docker run --name='mysql-slave' -d  \
  --net mysql_net  \
  -e 'MYSQL_MODE=slave' -e 'MYSQL_PASS=pass' \
  -e 'REPLICATION_HOST=mysql-master' \
  -e 'DB_REMOTE_USER=dbuser' -e 'DB_REMOTE_PASS=dbpass' \
  romeoz/docker-mysql

Variables DB_REMOTE_USER and DB_REMOTE_PASS is master settings.

or import as backup file

docker run --name='mysql-slave' -d  \
  --net mysql_net  \
  -e 'MYSQL_MODE=slave' -e 'MYSQL_PASS=pass' \
  -e 'REPLICATION_HOST=mysql-master' \
  -e 'MYSQL_RESTORE=/tmp/backup/backup.last.bz2' \
  -v /host/to/path/backup:/tmp/backup \
  romeoz/docker-mysql

Protection against unauthorized inserting records docker exec -it mysql-slave mysql -uroot -e 'GRANT SELECT ON *.* TO "web"@"%" WITH GRANT OPTION;'

Environment variables

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

MYSQL_PASS: Set a specific password for the admin account.

MYSQL_MODE: Set a specific mode. Takes on the values master, slave or backup.

MYSQL_BACKUP_DIR: Set a specific backup directory (default '/tmp/backup').

MYSQL_BACKUP_FILENAME: Set a specific filename backup (default 'backup.last.bz2').

MYSQL_CHECK: Defines one SQL script/dump to initialize the database. Note that the dump must be inside the container, so you may need to mount them. You can specify as default that is equivalent to the /tmp/backup/backup.last.bz2

MYSQL_RESTORE: Defines one or more SQL scripts/dumps separated by spaces to initialize the database. Note that the scripts must be inside the container, so you may need to mount them. You can specify as default that is equivalent to the /tmp/backup/backup.last.bz2

MYSQL_ROTATE_BACKUP: Determines whether to use the rotation of backups (default "true").

REPLICATION_PORT: Set a specific replication port for the master instance (default '3306').

REPLICATION_USER: Set a specific replication username for the master instance (default 'replica').

REPLICATION_PASS: Set a specific replication password for the master instance (default 'replica').

Logging

All the logs are forwarded to stdout and sterr. You have use the command docker logs.

docker logs mysql

####Split the logs

You can then simply split the stdout & stderr of the container by piping the separate streams and send them to files:

docker logs mysql > stdout.log 2>stderr.log
cat stdout.log
cat stderr.log

or split stdout and error to host stdout:

docker logs mysql > -
docker logs mysql 2> -

####Rotate logs

Create the file /etc/logrotate.d/docker-containers with the following text inside:

/var/lib/docker/containers/*/*.log {
    rotate 31
    daily
    nocompress
    missingok
    notifempty
    copytruncate
}

Optionally, you can replace nocompress to compress and change the number of days.

Out of the box

• Ubuntu 14.04 or 16.04 LTS
• MySQL 5.5, 5.6 or 5.7

Environment depends on the version of MySQL.

License

MySQL docker image is open-sourced software licensed under the MIT license.