Helm chart for deploying MariaDB Galera Cluster on Kubernetes
Switch branches/tags
Nothing to show
Clone or download
tongpu Merge pull request #1 from meabolex/master
updated init containers syntax to k8s 1.8+
Latest commit 469a5d4 Dec 21, 2017

README.md

MariaDB Galera Cluster

MariaDB is one of the most popular database servers in the world. It’s made by the original developers of MySQL and guaranteed to stay open source. Notable users include Wikipedia, Facebook and Google.

Galera Cluster is a multi-master solution for MariaDB which provides an easy-to-use, high-availability solution for MariaDB based databases.

Introduction

This chart bootstraps a MariaDB Galera Cluster deployment on a Kubernetes cluster using the Helm package manager.

Prerequisites

  • Kubernetes 1.5+ with Beta APIs enabled
  • PV provisioner support in the underlying infrastructure

Installing the Chart

To install the chart with the release name my-release:

$ helm install --name my-release incubator/mariadb-galera

The command deploys MariaDB Galera Cluster on the Kubernetes cluster in the default configuration. The configuration section lists the parameters that can be configured during installation.

Tip: List all releases using helm list

Uninstalling the Chart

To uninstall/delete the my-release deployment:

$ helm delete my-release

The command removes all the Kubernetes components associated with the chart and deletes the release.

Configuration

The following tables lists the configurable parameters of the MariaDB chart and their default values.

Parameter Description Default
image MariaDB Galera image adfinissygroup/k8s-mariadb-galera-centos:v002
imagePullPolicy Image pull policy. IfNotPresent
mysqlRootPassword Password for the root user. random 16 character alphanumeric string
mysqlUser Username of new user to create. nil
mysqlPassword Password for the new user. nil
mysqlDatabase Name for new database to create. nil
replicas Number of replicas to deploy 3
persistence.enabled Use a PVC to persist data true
persistence.storageClass Storage class of backing PVC nil (uses alpha storage class annotation)
persistence.accessMode Use volume as ReadOnly or ReadWrite ReadWriteOnce
persistence.size Size of data volume 8Gi
resources CPU/Memory resource requests/limits Memory: 256Mi, CPU: 250m
config Multi-line string for my.cnf configuration nil

The above parameters map to the env variables defined in the adfinis-sygroup/openshift-mariadb-galera.

Specify each parameter using the --set key=value[,key=value] argument to helm install. For example,

$ helm install --name my-release \
  --set mysqlRootPassword=secretpassword,mysqlUser=my-user,mysqlPassword=my-password,mysqlDatabase=my-database \
    stable/mariadb-galera

The above command sets the MariaDB root account password to secretpassword. Additionally it creates a standard database user named my-user, with the password my-password, who has access to a database named my-database.

Alternatively, a YAML file that specifies the values for the parameters can be provided while installing the chart. For example,

$ helm install --name my-release -f values.yaml stable/mariadb-galera

Tip: You can use the default values.yaml

Random MariaDB root password

If you don't configure a password for the MariaDB root user, helm will generate a random one for you. You can get the configured password from the created Kubernetes secret:

$ kubectl get secret ${release_name}-mariadb-galera  -o jsonpath='{.data.mysql-root-password}' | base64 -d

Custom my.cnf configuration

The Adfinis SyGroup MariaDB Galera Cluster image allows you to provide a custom my_extra.cnf file for configuring MariaDB. This Chart uses the config value to mount a custom my_extra.cnf using a ConfigMap. You can configure this by creating a YAML file that defines the config property as a multi-line string in the format of a my.cnf file. For example:

cat > mariadb-values.yaml <<EOF
config: |-
  [mysqld]
  max_allowed_packet = 64M
  sql_mode=STRICT_ALL_TABLES
  ft_stopword_file=/etc/mysql/stopwords.txt
  ft_min_word_len=3
  ft_boolean_syntax=' |-><()~*:""&^'
  innodb_buffer_pool_size=2G
EOF

helm install --name my-release -f mariadb-values.yaml incubator/mariadb-galera

Persistence

The MariaDB Galera Chart image stores the MariaDB data files at the /var/lib/mysql path of the container.

The chart mounts a Persistent Volume at this location in every pod of the StatefulSet. The volume is either created using dynamic volume provisioning or must be created manually.