Running Percona Server for MySQL in a Docker Container¶
Docker images of Percona Server for MySQL 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may be outdated and cause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.
By default, Docker will pull the image from Docker Hub if it is not available locally.
Using the Percona Server for MySQL Images¶
The following procedure describes how to run and access Percona Server 8.0 using Docker.
Starting an Instance of Percona Server for MySQL in a Container¶
To start a container named ps
running the latest version of
Percona Server for MySQL 8.0, with the root password set to root
:
[root@docker-host] $ docker run -d \
--name ps \
-e MYSQL_ROOT_PASSWORD=root \
percona/percona-server:8.0
Important
root
is not a secure password.
Note
The docker stop command sends a TERM signal. Docker waits 10 seconds and sends a KILL signal. Very large instances cannot dump the data from memory to disk in 10 seconds. If you plan to run a very large instance, add the following option to the docker run command.
–stop-timeout 600
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: 8.0.13-3 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 for MySQL 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:
MYSQL_ALLOW_EMPTY_PASSWORD
: least secure, use only for testing.MYSQL_ROOT_PASSWORD
: more secure, but setting the password on the command line is not recommended for sensitive production setups.MYSQL_RANDOM_ROOT_PASSWORD
: most secure, recommended for production.Note
To further secure your instance, use the
MYSQL_ONETIME_PASSWORD
variable if you are running version 5.6 or later.
-
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 theMYSQL_USER
andMYSQL_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 theMYSQL_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 thedocker 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 theMYSQL_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:8.0
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 for MySQL.
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:8.0
Passing Options to Percona Server for MySQL¶
You can pass options to Percona Server for MySQL when running the container
by appending them to the docker run
command.
For example, to start run Percona Server for MySQL 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:8.0 \
--character-set-server=utf8 \
--collation-server=utf8_general_ci
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