MariaDB Galera cluster on OpenShift

Requirements

• OpenShift Origin 1.3 or Enterprise 3.3 OR
• Kubernetes 1.3+

General informations

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)

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

Volume mount point	Description
/var/lib/mysql	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 in OpenShift

Importing templates

Import the templates into OpenShift with the following commands:

$ oc create -f mariadb-galera-ephemeral-template.yml -n openshift
$ oc create -f mariadb-galera-persistent-template.yml -n openshift

Creating a cluster with templates

• Navigate to the OpenShift web console
• Choose your project and click add to Project
• Choose one of the two mariadb-galera templates

If choosing the persistent template, make sure that the PV's are created in the namespace of your project and match the VOLUME_PV_NAME and VOLUME_CAPACITY parameters of the template.

Manual cluster creation

• Create PV's as cluster admin:

$ oc create -f galera-pv-nfs.yml -n yourproject

• Then create the service and petset itself:

$ oc create -f galera.yml

Manual cluster cleanup

$ oc delete petset mysql
$ oc delete svc galera
$ oc delete pod mysql-0 mysql-1 mysql-2
$ oc delete pv datadir-mysql-0 datadir-mysql-1 datadir-mysql-2

Usage in Kubernetes

This image runs on kubernetes as well.

Create cluster

$ kubectl create -f galera-pv-host.yml
$ kubectl create -f galera.yml

For Kubernetes v1.5 the API endpoints have changed you need to use the definition in galera_k8s_v1.6.yml.

$ kubectl create -f galera-pv-host.yml
$ kubectl create -f galera_k8s_v1.6.yml

Cleanup cluster

$ kubectl delete petset mysql
$ kubectl delete svc galera
$ kubectl delete pod mysql-0 mysql-1 mysql-2
$ kubectl delete pv datadir-mysql-0 datadir-mysql-1 datadir-mysql-2

Building

$ git clone https://github.com/adfinis-sygroup/openshift-mariadb-galera
$ cd k8s-mariadb-galera-centos
$ make

Technical informations how the image works in detail can be found here

Contributions

Contributions are more than welcome! Please feel free to open new issues or pull requests.

License

GNU GENERAL PUBLIC LICENSE Version 3

See the LICENSE file.