charts/bitnami/mariadb-galera

MariaDB Galera

MariaDB Galera is a multi-master database cluster solution for synchronous replication and high availability.

TL;DR;

$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/mariadb-galera

Introduction

This chart bootstraps a MariaDB Galera cluster on Kubernetes 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 fluentd and Prometheus on top of BKPR.

Prerequisites

• Kubernetes 1.10+
• PV provisioner support in the underlying infrastructure

Note: Please, note that mariadb-galera container runs as root by default in order to enable LDAP support for now.

Installing the Chart

Add the bitnami charts repo to Helm:

$ helm repo add bitnami https://charts.bitnami.com/bitnami

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

$ helm install my-release bitnami/mariadb-galera

The command deploys MariaDB Galera 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

For a graceful termination, set the replica count of the Pods in the mariadb-galera StatefulSet to 0:

$ kubectl scale sts my-release-mariadb-galera --replicas=0

To uninstall/delete the my-release release:

$ helm delete --purge 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 Galera chart and their default values.

Parameter	Description	Default
global.imageRegistry	Global Docker image registry	nil
global.imagePullSecrets	Global Docker registry secret names as an array	[] (does not add image pull secrets to deployed pods)
global.storageClass	Global storage class for dynamic provisioning	nil
image.registry	MariaDB Galera image registry	docker.io
image.repository	MariaDB Galera Image name	bitnami/mariadb-galera
image.tag	MariaDB Galera Image tag	{TAG_NAME}
image.pullPolicy	MariaDB Galera image pull policy	IfNotPresent
image.pullSecrets	Specify docker-registry secret names as an array	[] (does not add image pull secrets to deployed pods)
image.debug	Specify if debug logs should be enabled	false
nameOverride	String to partially override mariadb-galera.fullname template with a string (will prepend the release name)	nil
fullnameOverride	String to fully override mariadb-galera.fullname template with a string	nil
schedulerName	Name of the k8s scheduler (other than default)	nil
service.type	Kubernetes service type	ClusterIP
service.port	MariaDB service port	3306
service.clusterIP	Specific cluster IP when service type is cluster IP. Use None for headless service	nil
service.nodePort	Kubernetes Service nodePort	nil
service.loadBalancerIP	loadBalancerIP if service type is LoadBalancer	nil
service.loadBalancerSourceRanges	Address that are allowed when svc is LoadBalancer	[]
service.annotations	Additional annotations for MariaDB Galera service	{}
clusterDomain	Kubernetes DNS Domain name to use	cluster.local
serviceAccount.create	Specify whether a ServiceAccount should be created	false
serviceAccount.name	The name of the ServiceAccount to create	Generated using the mariadb-galera.fullname template
rbac.create	Specify whether RBAC resources should be created and used	false
securityContext.enabled	Enable security context	false
securityContext.fsGroup	Group ID for the container filesystem	1001
securityContext.runAsUser	User ID for the container	1001
existingSecret	Use existing secret for password details (rootUser.password, db.password, galera.mariabackup.password will be ignored and picked up from this secret)	nil
rootUser.password	Password for the root user. Ignored if existing secret is provided.	random 10 character alphanumeric string
rootUser.forcePassword	Force users to specify a password	false
db.user	Username of new user to create	nil
db.password	Password for the new user. Ignored if existing secret is provided.	random 10 character alphanumeric string if db.user is defined
db.name	Name for new database to create	my_database
db.forcePassword	Force users to specify a password	false
galera.name	Galera cluster name	galera
galera.mariabackup.user	Galera mariabackup user	mariabackup
galera.mariabackup.password	Galera mariabackup password	random 10 character alphanumeric string
galera.mariabackup.forcePassword	Force users to specify a password	false
ldap.enabled	Enable LDAP support	false
ldap.uri	LDAP URL beginning in the form ldap[s]://<hostname>:<port>	nil
ldap.base	LDAP base DN	nil
ldap.binddn	LDAP bind DN	nil
ldap.bindpw	LDAP bind password	nil
ldap.bslookup	LDAP base lookup	nil
ldap.nss_initgroups_ignoreusers	LDAP ignored users	root,nslcd
ldap.scope	LDAP search scope	nil
ldap.tls_reqcert	LDAP TLS check on server certificates	nil
mariadbConfiguration	Configuration for the MariaDB server	_default values in the values.yaml file_
configurationConfigMap	ConfigMap with the MariaDB configuration files (Note: Overrides mariadbConfiguration). The value is evaluated as a template.	nil
initdbScripts	Dictionary of initdb scripts	nil
initdbScriptsConfigMap	ConfigMap with the initdb scripts (Note: Overrides initdbScripts)	nil
extraFlags	MariaDB additional command line flags	nil
annotations[].key	key for the the annotation list item	nil
annotations[].value	value for the the annotation list item	nil
replicaCount	Desired number of cluster nodes	3
updateStrategy	Statefulset update strategy policy	RollingUpdate
affinity	Map of node/pod affinities	{} (The value is evaluated as a template)
nodeSelector	Node labels for pod assignment (this value is evaluated as a template)	{}
tolerations	List of node taints to tolerate (this value is evaluated as a template)	[]
persistence.enabled	Enable persistence using PVC	true
persistence.existingClaim	Provide an existing PersistentVolumeClaim	nil
persistence.subPath	Subdirectory of the volume to mount	nil
persistence.mountPath	Path to mount the volume at	/bitnami/mariadb
persistence.annotations	Persistent Volume Claim annotations	{}
persistence.storageClass	Persistent Volume Storage Class	nil
persistence.accessModes	Persistent Volume Access Modes	[ReadWriteOnce]
persistence.size	Persistent Volume Size	8Gi
podLabels	Additional pod labels	{}
priorityClassName	Priority Class Name for Statefulset	``
extraInitContainers	Additional init containers (this value is evaluated as a template)	[]
extraContainers	Additional containers (this value is evaluated as a template)	[]
extraVolumes	Extra volumes	nil
extraVolumeMounts	Mount extra volume(s)	nil
resources	CPU/Memory resource requests/limits for node	{}
livenessProbe.enabled	Turn on and off liveness probe	true
livenessProbe.initialDelaySeconds	Delay before liveness probe is initiated	120
livenessProbe.periodSeconds	How often to perform the probe	10
livenessProbe.timeoutSeconds	When the probe times out	1
livenessProbe.successThreshold	Minimum consecutive successes for the probe	1
livenessProbe.failureThreshold	Minimum consecutive failures for the probe	3
readinessProbe.enabled	Turn on and off readiness probe	true
readinessProbe.initialDelaySeconds	Delay before readiness probe is initiated	30
readinessProbe.periodSeconds	How often to perform the probe	10
readinessProbe.timeoutSeconds	When the probe times out	1
readinessProbe.successThreshold	Minimum consecutive successes for the probe	1
readinessProbe.failureThreshold	Minimum consecutive failures for the probe	3
podDisruptionBudget.create	If true, create a pod disruption budget for pods.	false
podDisruptionBudget.minAvailable	Minimum number / percentage of pods that should remain scheduled	1
podDisruptionBudget.maxUnavailable	Maximum number / percentage of pods that may be made unavailable	nil
metrics.enabled	Start a side-car prometheus exporter	false
metrics.image.registry	MariaDB Prometheus exporter image registry	docker.io
metrics.image.repository	MariaDB Prometheus exporter image name	bitnami/mysqld-exporter
metrics.image.tag	MariaDB Prometheus exporter image tag	{TAG_NAME}
metrics.image.pullPolicy	MariaDB Prometheus exporter image pull policy	IfNotPresent
metrics.resources	Prometheus exporter resource requests/limits	{}
metrics.service.annotations	Prometheus exporter svc annotations	{prometheus.io/scrape: "true", prometheus.io/port: "9104"}
metrics.serviceMonitor.enabled	if true, creates a Prometheus Operator ServiceMonitor (also requires metrics.enabled to be true)	false
metrics.serviceMonitor.namespace	Optional namespace which Prometheus is running in	nil
metrics.serviceMonitor.interval	How frequently to scrape metrics (use by default, falling back to Prometheus' default)	nil
metrics.serviceMonitor.selector	Default to kube-prometheus install (CoreOS recommended), but should be set according to Prometheus install	{prometheus: "kube-prometheus"}

The above parameters map to the env variables defined in bitnami/mariadb-galera. For more information please refer to the bitnami/mariadb-galera 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,
  --set db.user=app_database \
    bitnami/mariadb-galera

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 bitnami/mariadb-galera

Tip

: You can use the default values.yaml

Passing extra command-line flags to mysqld startup

While the chart allows you to specify the server configuration using the .mariadbConfiguration chart parameter, some options for the MariaDB server can only be specified via command line flags. For such cases, the chart exposes the .extraFlags parameter.

For example, if you want to enable the PAM cleartext plugin, specify the command line parameter while deploying the chart like so:

$ helm install my-release \
  --set extraFlags="--pam-use-cleartext-plugin=ON" \
  bitnami/mariadb-galera

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:

- rootUser.forcePassword: false
+ rootUser.forcePassword: true
- db.forcePassword: false
+ db.forcePassword: true
- galera.mariabackup.forcePassword: false
+ galera.mariabackup..forcePassword: true

• Start a side-car prometheus exporter:

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

LDAP

LDAP support can be enabled in the chart by specifying the ldap. parameters while creating a release. The following parameters should be configured to properly enable the LDAP support in the chart.

• ldap.enabled: Enable LDAP support. Defaults to false.
• ldap.uri: LDAP URL beginning in the form ldap[s]://<hostname>:<port>. No defaults.
• ldap.base: LDAP base DN. No defaults.
• ldap.binddn: LDAP bind DN. No defaults.
• ldap.bindpw: LDAP bind password. No defaults.
• ldap.bslookup: LDAP base lookup. No defaults.
• ldap.nss_initgroups_ignoreusers: LDAP ignored users. root,nslcd.
• ldap.scope: LDAP search scope. No defaults.
• ldap.tls_reqcert: LDAP TLS check on server certificates. No defaults.

For example:

ldap.enabled="true"
ldap.uri="ldap://my_ldap_server"
ldap.base="dc=example,dc=org"
ldap.binddn="cn=admin,dc=example,dc=org"
ldap.bindpw="admin"
ldap.bslookup="ou=group-ok,dc=example,dc=org"
ldap.nss_initgroups_ignoreusers="root,nslcd"
ldap.scope="sub"
ldap.tls_reqcert="demand"

Next, login to the MariaDB server using the mysql client and add the PAM authenticated LDAP users.

For example,

CREATE USER 'bitnami'@'localhost' IDENTIFIED VIA pam USING 'mariadb';

With the above example, when the bitnami user attempts to login to the MariaDB server, he/she will be authenticated against the LDAP server.

Initialize a fresh instance

The Bitnami MariaDB Galera 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 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 pod that reports to an external resource that the db is going to starting. values.yaml

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

Extra Containers

The feature allows for specifying additional containers in the pod. Usecases include situations when you need to run some sidecar containers. For example, you can observe if mysql in pod is running and report to some service discovery software like eureka. Example: values.yaml

extraContainers:
- name: '{{ .Chart.Name }}-eureka-sidecar'
  image: 'image:tag'
  env:
  - name: SERVICE_NAME
    value: '{{ template "mariadb-galera.fullname" . }}'
  - name: EUREKA_APP_NAME
    value: '{{ template "mariadb-galera.name" . }}'
  - name: MARIADB_USER
    value: '{{ .Values.db.user }}'
  - name: MARIADB_PASSWORD
    valueFrom:
      secretKeyRef:
        name: '{{ template "mariadb-galera.fullname" . }}'
        key: mariadb-password
  resources:
    limits:
      cpu: 100m
      memory: 20Mi
    requests:
      cpu: 50m
      memory: 10Mi

Persistence

The Bitnami MariaDB Galera 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.

Upgrading

It's necessary to specify the existing passwords while performing a upgrade to ensure the secrets are not updated with invalid randomly generated passwords. Remember to specify the existing values of the rootUser.password, db.password and galera.mariabackup.password parameters when upgrading the chart:

$ helm upgrade my-release bitnami/mariadb-galera \
    --set rootUser.password=[ROOT_PASSWORD] \
    --set db.password=[MARIADB_PASSWORD] \
    --set galera.mariabackup.password=[GALERA_MARIABACKUP_PASSWORD]

| Note: you need to substitute the placeholders [ROOT_PASSWORD], [MARIADB_PASSWORD] and [MARIABACKUP_PASSWORD] with the values obtained from instructions in the installation notes.