Running Percona Server in a Docker Container

Docker images of Percona Server are hosted publicly on Docker Hub at https://hub.docker.com/r/percona/percona-server/.

For more information about using Docker, see the Docker Docs.

Note

Make sure that you are using the latest version of Docker. The ones provided via apt and yum may be outdated and cause errors.

Note

By default, Docker will pull the image from Docker Hub if it is not available locally.

Using the Percona Server Images

The following procedure describes how to run and access Percona Server 5.7 using Docker.

Starting a Percona Server Instance in a Container

To start a container named ps running the latest version in the Percona Server 5.7 series, with the root password set to root:

[root@docker-host] $ docker run -d \
  --name ps \
  -e MYSQL_ROOT_PASSWORD=root \
  percona/percona-server:5.7

Note

root is not a secure password.

Accessing the Percona Server Container

To access the shell in the container:

[root@docker-host] $ docker exec -it ps /bin/bash

From the shell, you can view the error log:

[mysql@ps] $ more /var/log/mysql/error.log
2017-08-29T04:20:22.190474Z 0 [Warning] 'NO_ZERO_DATE', 'NO_ZERO_IN_DATE' and 'ERROR_FOR_DIVISION_BY_ZERO' sql modes should be used with strict mode. They will be merged with strict mode in a future release.
2017-08-29T04:20:22.190520Z 0 [Warning] 'NO_AUTO_CREATE_USER' sql mode was not set.
...

You can also run the MySQL command-line client to access the database directly:

[mysql@ps] $ mysql -uroot -proot
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.19-17 Percona Server (GPL), Release '17', Revision 'e19a6b7b73f'

Copyright (c) 2009-2017 Percona LLC and/or its affiliates
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

Accessing Percona Server from Application in Another Container

The image exposes the standard MySQL port 3306, so container linking makes Percona Server instance available from other containers. To link a container running your application (in this case, from image named app/image) with the Percona Server container, run it with the following command:

[root@docker-host] $ docker run -d \
  --name app \
  --link ps \
  app/image:latest

This application container will be able to access the Percona Server container via port 3306.

Environment Variables

When running a Docker container with Percona Server, you can adjust the configuration of the instance by passing one or more environment variables with the docker run command.

Note

These variables will not have any effect if you start the container with a data directory that already contains a database: any pre-existing database will always remain untouched on container startup.

The variables are optional, except that you must specify at least one of the following:

variable MYSQL_ALLOW_EMPTY_PASSWORD

Specifies whether to allow the container to be started with a blank password for the MySQL root user. Disabled by default. To enable, set MYSQL_ALLOW_EMPTY_PASSWORD=yes.

Note

Allowing empty root password is not recommended for production, because anyone will have full superuser access to the database.

variable MYSQL_DATABASE

Specifies the name of the database to be created when running the container. To create a user with full access to this database (GRANT ALL), set the MYSQL_USER and MYSQL_PASSWORD variables.

variable MYSQL_ONETIME_PASSWORD

Specifies whether the password for the MySQL root user should be set as expired. Disabled by default. If enabled using MYSQL_ONETIME_PASSWORD=yes, the MySQL root password must be changed before using it to log in.

variable MYSQL_PASSWORD

Specifies the password for the user with full access to the database specified by the MYSQL_DATABASE variable. Setting the MYSQL_USER variable is also required.

variable MYSQL_RANDOM_ROOT_PASSWORD

Specifies whether a random password for the MySQL root user should be generated. Disabled by default. To enable, set MYSQL_RANDOM_ROOT_PASSWORD=yes.

The password will be printed to stdout in the container, and it can be viewed using the docker logs command.

variable MYSQL_ROOT_PASSWORD

Specifies the password for the MySQL root user.

Note

Setting the MySQL root password on the command line is insecure. It is recommended to set a random password using the MYSQL_RANDOM_ROOT_PASSWORD variable.

variable MYSQL_ROOT_PASSWORD_FILE

Specifies a file that will be read for the root user account. This can be a mounted file when you run your container. This can also be used in the scope of the Docker Secrets (Swarm mode) functionality.

variable MYSQL_USER

Specifies the name for the user with full access to the database specified by the MYSQL_DATABASE variable. Setting the MYSQL_PASSWORD variable is also required.

variable INIT_TOKUDB

Specifies whether to allow the container to be started with enabled TokuDB engine. Disabled by default. To enable, set INIT_TOKUDB=yes.

variable INIT_ROCKSDB

Specifies whether to allow the container to be started with enabled RocksDB engine. Disabled by default. To enable, set INIT_ROCKSDB=yes.

Storing Data

There are two ways to store data used by applications that run in Docker containers:

  • Let Docker manage the storage of your data by writing the database files to disk on the host system using its own internal volume management.
  • Create a data directory on the host system (outside the container on high performance storage) and mount it to a directory visible from inside the container. This places the database files in a known location on the host system, and makes it easy for tools and applications on the host system to access the files. The user should make sure that the directory exists, and that permissions and other security mechanisms on the host system are set up correctly.

For example, if you create a data directory on a suitable volume on your host system named /local/datadir, you run the container with the following command:

[root@docker-host] $ docker run -d \
  --name ps \
  -e MYSQL_ROOT_PASSWORD=root \
  -v /local/datadir:/var/lib/mysql \
  percona/percona-server:5.7

The -v /local/datadir:/var/lib/mysql option mounts the /local/datadir directory on the host to /var/lib/mysql in the container, which is the default data directory used by Percona Server.

Note

If you the Percona Server container instance with a data directory that already contains data (the mysql subdirectory where all our system tables are stored), the MYSQL_ROOT_PASSWORD variable should be omitted from the docker run command.

Note

If you have SELinux enabled, assign the relevant policy type to the new data directory, so that the container will be allowed to access it:

[root@docker-host] $ chcon -Rt svirt_sandbox_file_t /local/datadir

Port Forwarding

Docker allows mapping ports on the container to ports on the host system using the -p option. If you run the container with this option, you can connect to the database by connecting your client to a port on the host machine. This can greatly simplify consolidating many instances to a single host.

To map the standard MySQL port 3306 to port 6603 on the host:

[root@docker-host] $ docker run -d \
 --name ps \
 -e MYSQL_ROOT_PASSWORD=root \
 -p 6603:3306 \
 percona/percona-server:5.7

Passing Options to Percona Server

You can pass options to Percona Server when running the container by appending them to the docker run command. For example, to start run Percona Server with UTF-8 as the default setting for character set and collation for all databases:

[root@docker-host] $ docker run -d \
 --name ps \
 -e MYSQL_ROOT_PASSWORD=root \
 percona/percona-server:5.7 \
 --character-set-server=utf8 \
 --collation-server=utf8_general_ci