MariaDB

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.

MariaDB is developed as open source software and as a relational database it provides an SQL interface for accessing data. The latest versions of MariaDB also include GIS and JSON features.

This Helm chart is deprecated

Given the stable deprecation timeline, the Bitnami maintained MariaDB Helm chart is now located at bitnami/charts.

The Bitnami repository is already included in the Hubs and we will continue providing the same cadence of updates, support, etc that we've been keeping here these years. Installation instructions are very similar, just adding the bitnami repo and using it during the installation (bitnami/<chart> instead of stable/<chart>)

$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/<chart>           # Helm 3
$ helm install --name my-release bitnami/<chart>    # Helm 2

To update an exisiting stable deployment with a chart hosted in the bitnami repository you can execute

$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm upgrade my-release bitnami/<chart>

Issues and PRs related to the chart itself will be redirected to bitnami/charts GitHub repository. In the same way, we'll be happy to answer questions related to this migration process in this issue created as a common place for discussion.

TL;DR;

$ helm install my-release stable/mariadb

Introduction

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

Bitnami charts can be used with Kubeapps for deployment and management of Helm Charts in clusters. This chart has been tested to work with NGINX Ingress, cert-manager, fluentd and Prometheus on top of the BKPR.

Prerequisites

• Kubernetes 1.12+
• Helm 2.11+ or Helm 3.0-beta3+
• PV provisioner support in the underlying infrastructure

Installing the Chart

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

$ helm install my-release stable/mariadb

The command deploys MariaDB on the Kubernetes cluster in the default configuration. The Parameters 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.

Parameters

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

The above parameters map to the env variables defined in bitnami/mariadb. For more information please refer to the bitnami/mariadb image documentation.

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

$ helm install my-release \
  --set rootUser.password=secretpassword,db.user=app_database \
    stable/mariadb

The above command sets the MariaDB root account password to secretpassword. Additionally it creates 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 my-release -f values.yaml stable/mariadb

Tip: You can use the default values.yaml

Configuration and installation details

Rolling VS Immutable tags

It is strongly recommended to use immutable tags in a production environment. This ensures your deployment does not change automatically if the same tag is updated with a different image.

Bitnami will release a new chart updating its containers if a new version of the main container, significant changes, or critical vulnerabilities exist.

Production configuration

This chart includes a values-production.yaml file where you can find some parameters oriented to production configuration in comparison to the regular values.yaml. You can use this file instead of the default one.

• Force users to specify a password and mount secrets as volumes instead of using environment variables:

- rootUser.forcePassword: false
- rootUser.injectSecretsAsVolume: false
+ rootUser.forcePassword: true
+ rootUser.injectSecretsAsVolume: true
- db.forcePassword: false
- db.injectSecretsAsVolume: false
+ db.forcePassword: true
+ db.injectSecretsAsVolume: true
- replication.forcePassword: false
- replication.injectSecretsAsVolume: false
+ replication.forcePassword: true
+ replication.injectSecretsAsVolume: true

• Desired number of slave replicas:

- slave.replicas: 1
+ slave.replicas: 2

• Start a side-car prometheus exporter:

- metrics.enabled: false
+ metrics.enabled: true

Initialize a fresh instance

The Bitnami MariaDB image allows you to use your custom scripts to initialize a fresh instance. In order to execute the scripts, they must be located inside the chart folder files/docker-entrypoint-initdb.d so they can be consumed as a ConfigMap.

Alternatively, you can specify custom scripts using the initdbScripts parameter as dict.

In addition to these options, you can also set an external ConfigMap with all the initialization scripts. This is done by setting the initdbScriptsConfigMap parameter. Note that this will override the two previous options.

The allowed extensions are .sh, .sql and .sql.gz.

Extra Init Containers

The feature allows for specifying a template string for a initContainer in the master/slave pod. Usecases include situations when you need some pre-run setup. For example, in IKS (IBM Cloud Kubernetes Service), non-root users do not have write permission on the volume mount path for NFS-powered file storage. So, you could use a initcontainer to chown the mount. See a example below, where we add an initContainer on the master pod that reports to an external resource that the db is going to starting. values.yaml

master:
  extraInitContainers: |
    - name: initcontainer
      image: bitnami/minideb:buster
      command: ["/bin/sh", "-c"]
      args:
        - install_packages curl && curl http://api-service.local/db/starting;

Persistence

The Bitnami MariaDB image stores the MariaDB data and configurations at the /bitnami/mariadb path of the container.

The chart mounts a Persistent Volume volume at this location. The volume is created using dynamic volume provisioning, by default. An existing PersistentVolumeClaim can be defined.

Adjust permissions of persistent volume mountpoint

As the image run as non-root by default, it is necessary to adjust the ownership of the persistent volume so that the container can write data into it.

By default, the chart is configured to use Kubernetes Security Context to automatically change the ownership of the volume. However, this feature does not work in all Kubernetes distributions. As an alternative, this chart supports using an initContainer to change the ownership of the volume before mounting it in the final destination.

You can enable this initContainer by setting volumePermissions.enabled to true.

Upgrading

It's necessary to set the rootUser.password parameter when upgrading for readiness/liveness probes to work properly. When you install this chart for the first time, some notes will be displayed providing the credentials you must use under the 'Administrator credentials' section. Please note down the password and run the command below to upgrade your chart:

$ helm upgrade my-release stable/mariadb --set rootUser.password=[ROOT_PASSWORD]

| Note: you need to substitute the placeholder [ROOT_PASSWORD] with the value obtained in the installation notes.

To 7.0.0

Helm performs a lookup for the object based on its group (apps), version (v1), and kind (Deployment). Also known as its GroupVersionKind, or GVK. Changing the GVK is considered a compatibility breaker from Kubernetes' point of view, so you cannot "upgrade" those objects to the new GVK in-place. Earlier versions of Helm 3 did not perform the lookup correctly which has since been fixed to match the spec.

In https://github.com/helm/charts/pull/17308 the apiVersion of the statefulset resources was updated to apps/v1 in tune with the api's deprecated, resulting in compatibility breakage.

This major version bump signifies this change.

To 6.0.0

MariaDB version was updated from 10.1 to 10.3, there are no changes in the chart itself. According to the official documentation, upgrading from 10.1 should be painless. However, there are some things that have changed which could affect an upgrade:

• Incompatible changes upgrading from MariaDB 10.1 to MariaDB 10.2
• Incompatible changes upgrading from MariaDB 10.2 to MariaDB 10.3

To 5.0.0

Backwards compatibility is not guaranteed unless you modify the labels used on the chart's deployments. Use the workaround below to upgrade from versions previous to 5.0.0. The following example assumes that the release name is mariadb:

$ kubectl delete statefulset opencart-mariadb --cascade=false