MySQL for OpenShift - Docker images

This repository contains Dockerfiles for MySQL images for OpenShift. Users can choose between RHEL and CentOS based images.

Versions

MySQL versions currently provided are:

mysql-5.5
mysql-5.6

RHEL versions currently supported are:

RHEL7

CentOS versions currently supported are:

CentOS7

Installation

Choose either the CentOS7 or RHEL7 based image:

RHEL7 based image

To build a RHEL7 based image, you need to run Docker build on a properly subscribed RHEL machine.

$ git clone https://github.com/openshift/mysql.git
$ cd mysql
$ make build TARGET=rhel7 VERSION=5.5

CentOS7 based image

This image is available on DockerHub. To download it run:

$ docker pull openshift/mysql-55-centos7

To build a MySQL image from scratch run:

$ git clone https://github.com/openshift/mysql.git
$ cd mysql
$ make build VERSION=5.5

For using other versions of mysql, just replace the 5.5 value by particular version in the commands above.

Notice: By omitting the VERSION parameter, the build/test action will be performed on all provided versions of MySQL, which must be specified in VERSIONS variable. This variable must be set to a list with possible versions (subdirectories).

Environment variables and volumes

The image recognizes the following environment variables that you can set during initialization by passing -e VAR=VALUE to the Docker run command.

Variable name	Description
`MYSQL_USER`	User name for MySQL account to be created
`MYSQL_PASSWORD`	Password for the user account
`MYSQL_DATABASE`	Database name
`MYSQL_ROOT_PASSWORD`	Password for the root user (optional)

The following environment variables influence the MySQL configuration file. They are all optional.

Variable name	Description	Default
`MYSQL_LOWER_CASE_TABLE_NAMES`	Sets how the table names are stored and compared	0
`MYSQL_MAX_CONNECTIONS`	The maximum permitted number of simultaneous client connections	151
`MYSQL_FT_MIN_WORD_LEN`	The minimum length of the word to be included in a FULLTEXT index	4
`MYSQL_FT_MAX_WORD_LEN`	The maximum length of the word to be included in a FULLTEXT index	20
`MYSQL_AIO`	Controls the `innodb_use_native_aio` setting value in case the native AIO is broken. See http://help.directadmin.com/item.php?id=529	1

You can also set the following mount points by passing the -v /host:/container flag to Docker.

Volume mount point	Description
`/var/lib/mysql/data`	MySQL data directory

Notice: When mouting a directory from the host into the container, ensure that the mounted directory has the appropriate permissions and that the owner and group of the directory matches the user UID or name which is running inside the container.

Usage

For this, we will assume that you are using the openshift/mysql-55-centos7 image. If you want to set only the mandatory environment variables and not store the database in a host directory, execute the following command:

$ docker run -d --name mysql_database -e MYSQL_USER=user -e MYSQL_PASSWORD=pass -e MYSQL_DATABASE=db -p 3306:3306 openshift/mysql-55-centos7

This will create a container named mysql_database running MySQL with database db and user with credentials user:pass. Port 3306 will be exposed and mapped to the host. If you want your database to be persistent across container executions, also add a -v /host/db/path:/var/lib/mysql/data argument. This will be the MySQL data directory.

If the database directory is not initialized, the entrypoint script will first run mysql_install_db and setup necessary database users and passwords. After the database is initialized, or if it was already present, mysqld is executed and will run as PID 1. You can stop the detached container by running docker stop mysql_database.

MySQL root user

The root user has no password set by default, only allowing local connections. You can set it by setting the MYSQL_ROOT_PASSWORD environment variable. This will allow you to login to the root account remotely. Local connections will still not require a password.

To disable remote root access, simply unset MYSQL_ROOT_PASSWORD and restart the container.

Changing passwords

Since passwords are part of the image configuration, the only supported method to change passwords for the database user (MYSQL_USER) and root user is by changing the environment variables MYSQL_PASSWORD and MYSQL_ROOT_PASSWORD, respectively.

Changing database passwords through SQL statements or any way other than through the environment variables aforementioned will cause a mismatch between the values stored in the variables and the actual passwords. Whenever a database container starts it will reset the passwords to the values stored in the environment variables.

Test

This repository also provides a test framework, which checks basic functionality of the MySQL image.

Users can choose between testing MySQL based on a RHEL or CentOS image.

RHEL based image

To test a RHEL7 based MySQL image, you need to run the test on a properly subscribed RHEL machine.
```
$ cd mysql
$ make test TARGET=rhel7 VERSION=5.5
```
CentOS based image
```
$ cd mysql
$ make test VERSION=5.5
```