MySQL

MySQL is a fast, reliable, scalable, and easy to use open-source relational database system. MySQL Server is intended for mission-critical, heavy-load production systems as well as for embedding into mass-deployed software.

TL;DR;

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

Introduction

This chart bootstraps a MySQL 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 Helm chart has been tested on top of Bitnami Kubernetes Production Runtime (BKPR). Deploy BKPR to get automated TLS certificates, logging and monitoring for your applications.

Prerequisites

• Kubernetes 1.12+
• Helm 2.12+ 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 repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/mysql

These commands deploy MySQL 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 tables lists the configurable parameters of the MySQL 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	MySQL image registry	docker.io
image.repository	MySQL Image name	bitnami/mysql
image.tag	MySQL Image tag	{TAG_NAME}
image.pullPolicy	MySQL 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 mysql.fullname template with a string (will prepend the release name)	nil
fullnameOverride	String to fully override mysql.fullname template with a string	nil
clusterDomain	Kubernetes DNS Domain name to use	cluster.local
volumePermissions.enabled	Enable init container that changes volume permissions in the data directory (for cases where the default k8s runAsUser and fsUser values do not work)	false
volumePermissions.image.registry	Init container volume-permissions image registry	docker.io
volumePermissions.image.repository	Init container volume-permissions image name	bitnami/minideb
volumePermissions.image.tag	Init container volume-permissions image tag	buster
volumePermissions.image.pullPolicy	Init container volume-permissions image pull policy	Always
volumePermissions.resources	Init container resource requests/limit	nil
existingSecret	Specify the name of an existing secret for password details (root.password, db.password, replication.password will be ignored and picked up from this secret). The secret has to contain the keys mysql-root-password, mysql-replication-password and mysql-password.	nil
root.password	Password for the root user	random 10 character alphanumeric string
root.forcePassword	Force users to specify a password. That is required for 'helm upgrade' to work properly	false
root.injectSecretsAsVolume	Mount admin user password as a file instead of using an environment variable	false
db.user	Username of new user to create (should be different from replication.user)	nil
db.password	Password for the new user	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. That is required for 'helm upgrade' to work properly	false
db.injectSecretsAsVolume	Mount user password as a file instead of using an environment variable	false
replication.enabled	MySQL replication enabled	true
replication.user	MySQL replication user (should be different from db.user)	replicator
replication.password	MySQL replication user password	random 10 character alphanumeric string
replication.forcePassword	Force users to specify a password. That is required for 'helm upgrade' to work properly	false
replication.injectSecretsAsVolume	Mount user password as a file instead of using an environment variable	false
initdbScripts	Dictionary of initdb scripts	nil
initdbScriptsConfigMap	ConfigMap with the initdb scripts (Note: Overrides initdbScripts)	nil
serviceAccount.create	Specifies whether a ServiceAccount should be created	true
serviceAccount.name	If serviceAccount.create is enabled, what should the serviceAccount name be - otherwise defaults to the fullname	nil
master.config	Config file for the MySQL Master server	_default values in the values.yaml file_
master.updateStrategy.type	Master statefulset update strategy policy	RollingUpdate
master.podAnnotations	Pod annotations for master nodes	{}
master.affinity	Map of node/pod affinities for master nodes	{} (The value is evaluated as a template)
master.nodeSelector	Node labels for pod assignment on master nodes	{} (The value is evaluated as a template)
master.tolerations	Tolerations for pod assignment on master nodes	[] (The value is evaluated as a template)
master.securityContext.enabled	Enable security context for master nodes	true
master.securityContext.fsGroup	Group ID for the master nodes' containers	1001
master.securityContext.runAsUser	User ID for the master nodes' containers	1001
master.containerSecurityContext	Container security context for master nodes' containers	{}
master.resources	CPU/Memory resource requests/limits for master nodes' containers	{}
master.livenessProbe.enabled	Turn on and off liveness probe (master nodes)	true
master.livenessProbe.initialDelaySeconds	Delay before liveness probe is initiated (master nodes)	120
master.livenessProbe.periodSeconds	How often to perform the probe (master nodes)	10
master.livenessProbe.timeoutSeconds	When the probe times out (master nodes)	1
master.livenessProbe.successThreshold	Minimum consecutive successes for the probe (master nodes)	1
master.livenessProbe.failureThreshold	Minimum consecutive failures for the probe (master nodes)	3
master.readinessProbe.enabled	Turn on and off readiness probe (master nodes)	true
master.readinessProbe.initialDelaySeconds	Delay before readiness probe is initiated (master nodes)	30
master.readinessProbe.periodSeconds	How often to perform the probe (master nodes)	10
master.readinessProbe.timeoutSeconds	When the probe times out (master nodes)	1
master.readinessProbe.successThreshold	Minimum consecutive successes for the probe (master nodes)	1
master.readinessProbe.failureThreshold	Minimum consecutive failures for the probe (master nodes)	3
master.extraEnvVars	Array containing extra env vars to configure MySQL master replicas	nil
master.extraEnvVarsCM	Configmap containing extra env vars to configure MySQL master replicas	nil
master.extraEnvVarsSecret	Secret containing extra env vars to configure MySQL master replicas	nil
master.persistence.enabled	Enable persistence using a PersistentVolumeClaim (master nodes)	true
master.persistence.mountPath	Configure PersistentVolumeClaim mount path (master nodes)	/bitnami/mysql
master.persistence.annotations	Persistent Volume Claim annotations (master nodes)	{}
master.persistence.storageClass	Persistent Volume Storage Class (master nodes)	``
master.persistence.accessModes	Persistent Volume Access Modes (master nodes)	[ReadWriteOnce]
master.persistence.size	Persistent Volume Size (master nodes)	8Gi
master.persistence.existingClaim	Provide an existing PersistentVolumeClaim (master nodes)	nil
slave.replicas	Desired number of slave replicas	1
slave.updateStrategy.type	Slave statefulset update strategy policy	RollingUpdate
slave.podAnnotations	Pod annotations for slave nodes	{}
slave.affinity	Map of node/pod affinities for slave nodes	{} (The value is evaluated as a template)
slave.nodeSelector	Node labels for pod assignment on slave nodes	{} (The value is evaluated as a template)
slave.tolerations	Tolerations for pod assignment on slave nodes	[] (The value is evaluated as a template)
slave.extraEnvVars	Array containing extra env vars to configure MySQL slave replicas	nil
slave.extraEnvVarsCM	ConfigMap containing extra env vars to configure MySQL slave replicas	nil
slave.extraEnvVarsSecret	Secret containing extra env vars to configure MySQL slave replicas	nil
slave.securityContext.enabled	Enable security context for slave nodes	true
slave.securityContext.fsGroup	Group ID for the slave nodes' containers	1001
slave.securityContext.runAsUser	User ID for the slave nodes' containers	1001
slave.containerSecurityContext	Container security context for slave nodes' containers	{}
slave.resources	CPU/Memory resource requests/limits for slave nodes' containers	{}
slave.livenessProbe.enabled	Turn on and off liveness probe (slave nodes)	true
slave.livenessProbe.initialDelaySeconds	Delay before liveness probe is initiated (slave nodes)	120
slave.livenessProbe.periodSeconds	How often to perform the probe (slave nodes)	10
slave.livenessProbe.timeoutSeconds	When the probe times out (slave nodes)	1
slave.livenessProbe.successThreshold	Minimum consecutive successes for the probe (slave nodes)	1
slave.livenessProbe.failureThreshold	Minimum consecutive failures for the probe (slave nodes)	3
slave.readinessProbe.enabled	Turn on and off readiness probe (slave nodes)	true
slave.readinessProbe.initialDelaySeconds	Delay before readiness probe is initiated (slave nodes)	30
slave.readinessProbe.periodSeconds	How often to perform the probe (slave nodes)	10
slave.readinessProbe.timeoutSeconds	When the probe times out (slave nodes)	1
slave.readinessProbe.successThreshold	Minimum consecutive successes for the probe (slave nodes)	1
slave.readinessProbe.failureThreshold	Minimum consecutive failures for the probe (slave nodes)	3
slave.persistence.enabled	Enable persistence using a PersistentVolumeClaim (slave nodes)	true
slave.persistence.mountPath	Configure PersistentVolumeClaim mount path (slave nodes)	/bitnami/mysql
slave.persistence.annotations	Persistent Volume Claim annotations (slave nodes)	{}
slave.persistence.storageClass	Persistent Volume Storage Class (slave nodes)	``
slave.persistence.accessModes	Persistent Volume Access Modes (slave nodes)	[ReadWriteOnce]
slave.persistence.size	Persistent Volume Size (slave nodes)	8Gi
slave.persistence.existingClaim	Provide an existing PersistentVolumeClaim (slave nodes)	nil
service.type	Kubernetes service type	ClusterIP
service.port	MySQL service port	3306
service.nodePort.master	Port to bind to for NodePort service type (master service)	nil
service.nodePort.slave	Port to bind to for NodePort service type (slave service)	nil
service.loadBalancerIP.master	Static IP Address to use for master LoadBalancer service type	nil
service.loadBalancerIP.slave	Static IP Address to use for slaves LoadBalancer service type	nil
service.annotations	Kubernetes service annotations	{}
metrics.enabled	Start a side-car prometheus exporter	false
metrics.image	Exporter image name	bitnami/mysqld-exporter
metrics.imageTag	Exporter image tag	{TAG_NAME}
metrics.imagePullPolicy	Exporter image pull policy	IfNotPresent
metrics.resources	Exporter resource requests/limit	nil
metrics.service.type	Kubernetes service type for MySQL Prometheus Exporter	ClusterIP
metrics.service.port	MySQL Prometheus Exporter service port	9104
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	nil	The above parameters map to the env variables defined in bitnami/mysql. For more information please refer to the bitnami/mysql image documentation.

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

$ helm install my-release \
  --set root.password=secretpassword,user.database=app_database \
    bitnami/mysql

The above command sets the MySQL root account password to secretpassword. Additionally it creates a database named app_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/mysql

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:

- root.forcePassword: false
+ root.forcePassword: true

- db.forcePassword: false
+ db.forcePassword: true

- replication.forcePassword: false
+ replication.forcePassword: true

• Desired number of slave replicas:

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

• Start a side-car prometheus exporter:

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

Change MySQL version

To modify the MySQL version used in this chart you can specify a valid image tag using the image.tag parameter. For example, image.tag=X.Y.Z. This approach is also applicable to other images like exporters.

Initialize a fresh instance

The Bitnami MySQL 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.

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

Persistence

The Bitnami MySQL image stores the MySQL data and configurations at the /bitnami/mysql 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 root.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 bitnami/mysql --set root.password=[ROOT_PASSWORD]

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

To 3.0.0

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 3.0.0. The following example assumes that the release name is mysql:

$ kubectl delete statefulset mysql-master --cascade=false
$ kubectl delete statefulset mysql-slave --cascade=false