charts/bitnami/redis-cluster

Redis Cluster

Redis is an advanced key-value cache and store. It is often referred to as a data structure server since keys can contain strings, hashes, lists, sets, sorted sets, bitmaps and hyperloglogs.

TL;DR;

# Testing configuration
$ helm install my-release bitnami/redis-cluster

# Production configuration
$ helm install my-release bitnami/redis-cluster --values values-production.yaml

Introduction

This chart bootstraps a Redis 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.

Choose between Redis Helm Chart and Redis Cluster Helm Chart

You can choose any of the two Redis Helm charts for deploying a Redis cluster. While Redis Helm Chart will deploy a master-slave cluster using Redis Sentinel, the Redis Cluster Helm Chart will deploy a Redis Cluster with sharding. The main features of each chart are the following:

Redis	Redis Cluster
Supports multiple databases	Supports only one database. Better if you have a big dataset
Single write point (single master)	Multiple write points (multiple masters)

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 install my-release bitnami/redis-cluster

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

NOTE: if you get a timeout error waiting for the hook to complete increase the default timeout (300s) to a higher one, for example:

helm install --timeout 600s myrelease bitnami/redis-cluster

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 Redis chart and their default values.

Global parameters

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
global.redis.password	Redis password (overrides password)	nil

Common parameters

Parameter	Description	Default
image.registry	Redis Image registry	docker.io
image.repository	Redis Image name	bitnami/redis
image.tag	Redis Image tag	{TAG_NAME}
image.pullPolicy	Image pull policy	IfNotPresent
image.pullSecrets	Specify docker-registry secret names as an array	nil
nameOverride	String to partially override redis.fullname template with a string (will prepend the release name)	nil
fullnameOverride	String to fully override redis.fullname template with a string	nil
existingSecret	Name of existing secret object (for password authentication)	nil
existingSecretPasswordKey	Name of key containing password to be retrieved from the existing secret	nil
usePassword	Use password	true
usePasswordFile	Mount passwords as files instead of environment variables	false
password	Redis password (ignored if existingSecret set)	Randomly generated
configmap	Additional common Redis node configuration (this value is evaluated as a template)	See values.yaml
networkPolicy.enabled	Enable NetworkPolicy	false
networkPolicy.allowExternal	Don't require client label for connections	true
networkPolicy.ingressNSMatchLabels	Allow connections from other namespaces	{}
networkPolicy.ingressNSPodMatchLabels	For other namespaces match by pod labels and namespace labels	{}
podSecurityContext.fsGroup	Group ID for the pods.	1001
podSecurityContext.sysctls	Set namespaced sysctls for the pods.	nil
podDisruptionBudget	Configure podDisruptionBudget policy	{}
containerSecurityContext.runAsUser	User ID for the containers.	1001
containerSecurityContext.sysctls	Set namespaced sysctls for the containers.	nil
serviceAccount.create	Specifies whether a ServiceAccount should be created	false
serviceAccount.name	The name of the ServiceAccount to create	Generated using the fullname template
rbac.create	Specifies whether RBAC resources should be created	false
rbac.role.rules	Rules to create	[]
persistence.enabled	Use a PVC to persist data.	true
persistence.path	Path to mount the volume at, to use other images	/bitnami/redis/data
persistence.subPath	Subdirectory of the volume to mount at	""
persistence.storageClass	Storage class of backing PVC	generic
persistence.accessModes	Persistent Volume Access Modes	[ReadWriteOnce]
persistence.size	Size of data volume	8Gi
persistence.matchLabels	matchLabels persistent volume selector	{}
persistence.matchExpressions	matchExpressions persistent volume selector	{}
statefulset.updateStrategy	Update strategy for StatefulSet	onDelete
statefulset.rollingUpdatePartition	Partition update strategy	nil
tls.enabled	Enable TLS support for replication traffic	false
tls.authClients	Require clients to authenticate or not	true
tls.certificatesSecret	Name of the secret that contains the certificates	nil
tls.certFilename	Certificate filename	nil
tls.certKeyFilename	Certificate key filename	nil
tls.certCAFilename	CA Certificate filename	nil
tls.dhParamsFilename	DH params (in order to support DH based ciphers)	nil
podSecurityPolicy.create	Specifies whether a PodSecurityPolicy should be created	false
service.port	Kubernetes Service port.	6379
service.annotations	annotations for redis service	{}
service.labels	Additional labels for redis service	{}
service.type	Service type for default redis service	ClusterIP
service.loadBalancerIP	loadBalancerIP if service.type is LoadBalancer	nil
volumePermissions.enabled	Enable init container that changes volume permissions in the registry (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 volume-permissions CPU/Memory resource requests/limits	{}
volumePermissions.image.pullSecrets	Specify docker-registry secret names as an array	[] (does not add image pull secrets to deployed pods)
commonLabels	Labels to add to all deployed objects	nil
commonAnnotations	Annotations to add to all deployed objects	[]
extraDeploy	Array of extra objects to deploy with the release (evaluated as a template).	nil

Redis statefulset parameters

Parameter	Description	Default
redis.port	Redis port.	6379
redis.useAOFPersistence	Enables AOF persistence mode	"yes"
redis.podLabels	Additional labels for Redis pod	{}
redis.command	Redis entrypoint string. The command redis-server is executed if this is not provided.	nil
redis.args	Arguments for the provided command if needed	nil
redis.schedulerName	Name of an alternate scheduler	nil
redis.configmap	Additional Redis configuration for the nodes (this value is evaluated as a template)	nil
redis.tolerations	Toleration labels for Redis pod assignment	[]
redis.nodeSelector	Node labels for pod assignment	{"beta.kubernetes.io/arch": "amd64"}
redis.podAnnotations	Additional annotations for Redis pod	{}
redis.busPort	Port for the Redis gossip protocol	16379
redis.lifecycleHooks	LifecycleHook to set additional configuration at startup. Evaluated as a template	``
redis.livenessProbe.enabled	Turn on and off liveness probe.	true
redis.livenessProbe.initialDelaySeconds	Delay before liveness probe is initiated.	30
redis.livenessProbe.periodSeconds	How often to perform the probe.	30
redis.livenessProbe.timeoutSeconds	When the probe times out.	5
redis.livenessProbe.successThreshold	Minimum consecutive successes for the probe to be considered successful after having failed.	1
redis.livenessProbe.failureThreshold	Minimum consecutive failures for the probe to be considered failed after having succeeded.	5
redis.readinessProbe.enabled	Turn on and off readiness probe.	true
redis.readinessProbe.initialDelaySeconds	Delay before readiness probe is initiated.	5
redis.readinessProbe.periodSeconds	How often to perform the probe.	10
redis.readinessProbe.timeoutSeconds	When the probe times out.	1
redis.readinessProbe.successThreshold	Minimum consecutive successes for the probe to be considered successful after having failed.	1
redis.readinessProbe.failureThreshold	Minimum consecutive failures for the probe to be considered failed after having succeeded.	5
redis.priorityClassName	Redis Master pod priorityClassName	{}
redis.customLivenessProbe	Override default liveness probe	nil
redis.customReadinessProbe	Override default readiness probe	nil
redis.extraVolumes	Array of extra volumes to be added to all pods (evaluated as a template). Requires setting extraVolumeMounts	[]
redis.extraVolumeMounts	Array of extra volume mounts to be added to all pods (evaluated as a template). Normally used with extraVolumes	[]
redis.affinity	Affinity settings for Redis pod assignment	{}
redis.topologySpreadConstraints	Pod topology spread constraints for Redis pod	[]
redis.extraEnvVars	Array containing extra env vars to be added to all pods (evaluated as a template)	[]
redis.extraEnvVarsCM	ConfigMap containing extra env vars to be added to all pods (evaluated as a template)	nil
redis.extraEnvVarsSecret	Secret containing extra env vars to be added to all pods (evaluated as a template)	nil
redis.initContainers	Init containers to add to the cronjob container	{}
redis.sidecars	Attach additional containers to the pod (evaluated as a template)	nil
redis.resources	Redis CPU/Memory resource requests/limits	Memory: 256Mi, CPU: 100m

Cluster initialization job parameters

Parameter	Description	Default
initJob.activeDeadlineSeconds	Maximum time (in seconds) to wait for the cluster initialization job to succeed	600
initJob.command	Entrypoint string.	nil
initJob.args	Arguments for the provided command if needed	nil
initJob.annotations	Job annotations	nil
initJob.podAnnotations	Job pod annotations	nil
initJob.extraEnvVars	Array containing extra env vars to be added to all pods (evaluated as a template)	[]
initJob.extraEnvVarsCM	ConfigMap containing extra env vars to be added to all pods (evaluated as a template)	nil
initJob.extraEnvVarsSecret	Secret containing extra env vars to be added to all pods (evaluated as a template)	nil
initJob.initContainers	Init containers to add to the cronjob container	{}
initJob.extraVolumes	Array of extra volumes to be added to all pods (evaluated as a template). Requires setting extraVolumeMounts	[]
initJob.extraVolumeMounts	Array of extra volume mounts to be added to all pods (evaluated as a template). Normally used with extraVolumes	[]
initJob.nodeSelector	Node labels for pod assignment	nil
initJob.podLabels	Additional labels	{}
initJob.tolerations	Toleration labels for Redis pod assignment	[]
initJob.resources	Redis CPU/Memory resource requests/limits	nil
initJob.affinity	Affinity settings for	{}

Cluster update job parameters

Parameter	Description	Default
updateJob.activeDeadlineSeconds	Maximum time (in seconds) to wait for the cluster initialization job to succeed	600
updateJob.command	Entrypoint string.	nil
updateJob.args	Arguments for the provided command if needed	nil
updateJob.annotations	Job annotations	nil
updateJob.podAnnotations	Job pod annotations	nil
updateJob.extraEnvVars	Array containing extra env vars to be added to all pods (evaluated as a template)	[]
updateJob.extraEnvVarsCM	ConfigMap containing extra env vars to be added to all pods (evaluated as a template)	nil
updateJob.extraEnvVarsSecret	Secret containing extra env vars to be added to all pods (evaluated as a template)	nil
updateJob.initContainers	Init containers to add to the cronjob container	{}
updateJob.extraVolumes	Array of extra volumes to be added to all pods (evaluated as a template). Requires setting extraVolumeMounts	[]
updateJob.extraVolumeMounts	Array of extra volume mounts to be added to all pods (evaluated as a template). Normally used with extraVolumes	[]
updateJob.nodeSelector	Node labels for pod assignment	nil
updateJob.podLabels	Additional labels	{}
updateJob.tolerations	Toleration labels for Redis pod assignment	[]
updateJob.resources	Redis CPU/Memory resource requests/limits	nil
updateJob.affinity	Affinity settings for	{}

Cluster management parameters

Parameter	Description	Default
cluster.init	Enable the creation of a job that initializes the Redis Cluster	true
cluster.nodes	Number of nodes in the Redis cluster	6
cluster.replicas	Number of replicas for every master in the cluster	1
cluster.externalAccess.enabled	Enable access to the Redis cluster from Outside the Kubernetes Cluster	false
cluster.externalAccess.service.type	Type for the services used to expose every Pod	LoadBalancer
cluster.externalAccess.service.port	Port for the services used to expose every Pod	6379
cluster.externalAccess.service.loadBalancerIP	Array of LoadBalancer IPs used to expose every Pod of the Redis cluster when cluster.externalAccess.service.type is LoadBalancer	[]
cluster.externalAccess.service.annotations	Annotations to add to the services used to expose every Pod of the Redis Cluster	{}
cluster.update.addNodes	Boolean to specify if you want to add nodes after the upgrade	false
cluster.update.currentNumberOfNodes	Number of currently deployed Redis nodes	6
cluster.update.newExternalIPs	External IPs obtained from the services for the new nodes to add to the cluster	nil

Metrics sidecar parameters

Parameter	Description	Default
metrics.enabled	Start a side-car prometheus exporter	false
metrics.image.registry	Redis exporter image registry	docker.io
metrics.image.repository	Redis exporter image name	bitnami/redis-exporter
metrics.image.tag	Redis exporter image tag	{TAG_NAME}
metrics.image.pullPolicy	Image pull policy	IfNotPresent
metrics.image.pullSecrets	Specify docker-registry secret names as an array	nil
metrics.extraArgs	Extra arguments for the binary; possible values here	{}
metrics.podLabels	Additional labels for Metrics exporter pod	{}
metrics.podAnnotations	Additional annotations for Metrics exporter pod	{}
metrics.resources	Exporter resource requests/limit	Memory: 256Mi, CPU: 100m
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.service.type	Kubernetes Service type (redis metrics)	ClusterIP
metrics.service.annotations	Annotations for the services to monitor.	{}
metrics.service.labels	Additional labels for the metrics service	{}
metrics.service.loadBalancerIP	loadBalancerIP if redis metrics service type is LoadBalancer	nil
metrics.prometheusRule.enabled	Set this to true to create prometheusRules for Prometheus operator	false
metrics.prometheusRule.additionalLabels	Additional labels that can be used so prometheusRules will be discovered by Prometheus	{}
metrics.prometheusRule.namespace	namespace where prometheusRules resource should be created	Same namespace as redis
metrics.prometheusRule.rules	rules to be created, check values for an example.	[]

Sysctl Image parameters

Parameter	Description	Default
sysctlImage.enabled	Enable an init container to modify Kernel settings	false
sysctlImage.command	sysctlImage command to execute	[]
sysctlImage.registry	sysctlImage Init container registry	docker.io
sysctlImage.repository	sysctlImage Init container name	bitnami/minideb
sysctlImage.tag	sysctlImage Init container tag	buster
sysctlImage.pullPolicy	sysctlImage Init container pull policy	Always
sysctlImage.mountHostSys	Mount the host /sys folder to /host-sys	false
sysctlImage.resources	sysctlImage Init container CPU/Memory resource requests/limits	{}
sysctlImage.pullSecrets	Specify docker-registry secret names as an array	nil

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

$ helm install my-release \
  --set password=secretpassword \
    bitnami/redis-cluster

The above command sets the Redis server password to secretpassword.

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/redis-cluster

Tip

: You can use the default values.yaml

Note for minikube users: Current versions of minikube (v0.24.1 at the time of writing) provision hostPath persistent volumes that are only writable by root. Using chart defaults cause pod failure for the Redis pod as it attempts to write to the /bitnami directory. Consider installing Redis with --set persistence.enabled=false. See minikube issue 1990 for more information.

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.

• Enable NetworkPolicy:

- networkPolicy.enabled: false
+ networkPolicy.enabled: true

• Start a side-car prometheus exporter:

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

Change Redis version

To modify the Redis 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.

Cluster topology

The Helm Chart will deploy by default 3 redis masters and 3 replicas. By default the Redis Cluster is not accessible from outside the Kubernetes cluster, to access the Redis Cluster from outside you have to set cluster.externalAccess.enabled=true at deployment time. It will create in the first installation only 6 LoadBalancer services, one for each Redis node, once you have the external IPs of each service you will need to perform an upgrade passing those IPs to the cluster.externalAccess.service.loadbalancerIP array.

The replicas will be read-only replicas of the masters. By default only one service is exposed (when not using the external access mode). You will connect your client to the exposed service, regardless you need to read or write. When a write operation arrives to a replica it will redirect the client to the proper master node. For example, using redis-cli you will need to provide the -c flag for redis-cli to follow the redirection automatically.

Using the external access mode, you can connect to any of the pods and the slaves will redirect the client in the same way as explained before, but the all the IPs will be public.

In case the master crashes, one of his slaves will be promoted to master. The slots stored by the crashed master will be unavailable until the slave finish the promotion. If a master and all his slaves crash, the cluster will be down until one of them is up again. To avoid downtime, it is possible to configure the number of Redis nodes with cluster.nodes and the number of replicas that will be assigned to each master with cluster.replicas. For example:

• cluster.nodes=9 ( 3 master plus 2 replicas for each master)
• cluster.replicas=2

Providing the values above, the cluster will have 3 masters and, each master, will have 2 replicas.

NOTE: By default cluster.init will be set to true in order to initialize the Redis Cluster in the first installation. If for testing purposes you only want to deploy or upgrade the nodes but avoiding the creation of the cluster you can set cluster.init to false.

Adding a new node to the cluster

There is a job that will be executed using a post-upgrade hook that will allow you to add a new node. To use it, you should provide some parameters to the upgrade:

• Pass as password the password used in the installation time. If you did not provide a password follow the intructions from the NOTES.txt to get the generated password.
• Set the desired number of nodes at cluster.nodes.
• Set the number of current nodes at cluster.update.currentNumberOfNodes.
• Set to true cluster.update.addNodes.

The following will be an example to add one more node:

helm upgrade --timeout 600s <release> --set "password=${REDIS_PASSWORD},cluster.nodes=7,cluster.update.addNodes=true,cluster.update.currentNumberOfNodes=6" bitnami/redis-cluster

Where REDIS_PASSWORD is the password obtained with the command that appears after the first installation of the Helm Chart. The cluster will continue up while restarting pods one by one as the quorum is not lost.

External Access

If you are using external access, to add a new node you will need to perform two upgrades. First upgrade the release to add a new Redis node and to get a LoadBalancerIP service. For example:

helm upgrade <release> --set "password=${REDIS_PASSWORD},cluster.externalAccess.enabled=true,cluster.externalAccess.service.type=LoadBalancer,cluster.externalAccess.service.loadBalancerIP[0]=<loadBalancerip-0>,cluster.externalAccess.service.loadBalancerIP[1]=<loadbalanacerip-1>,cluster.externalAccess.service.loadBalancerIP[2]=<loadbalancerip-2>,cluster.externalAccess.service.loadBalancerIP[3]=<loadbalancerip-3>,cluster.externalAccess.service.loadBalancerIP[4]=<loadbalancerip-4>,cluster.externalAccess.service.loadBalancerIP[5]=<loadbalancerip-5>,cluster.externalAccess.service.loadBalancerIP[6]=,cluster.nodes=7,cluster.init=false bitnami/redis-cluster

Important here to provide the loadBalancerIP parameters for the new nodes empty to not get an index error.

As we want to add a new node, we are setting cluster.nodes=7 and we leave empty the LoadBalancerIP for the new node, so the cluster will provide the correct one. REDIS_PASSWORD is the password obtained with the command that appears after the first installation of the Helm Chart. At this point, you will have a new Redis Pod that will remain in crashLoopBackOff state until we provide the LoadBalancerIP for the new service. Now, wait until the cluster provides the new LoadBalancerIP for the new service and perform the second upgrade:

helm upgrade <release> --set "password=${REDIS_PASSWORD},cluster.externalAccess.enabled=true,cluster.externalAccess.service.type=LoadBalancer,cluster.externalAccess.service.loadBalancerIP[0]=<loadbalancerip-0>,cluster.externalAccess.service.loadBalancerIP[1]=<loadbalancerip-1>,cluster.externalAccess.service.loadBalancerIP[2]=<loadbalancerip-2>,cluster.externalAccess.service.loadBalancerIP[3]=<loadbalancerip-3>,cluster.externalAccess.service.loadBalancerIP[4]=<loadbalancerip-4>,cluster.externalAccess.service.loadBalancerIP[5]=<loadbalancerip-5>,cluster.externalAccess.service.loadBalancerIP[6]=<loadbalancerip-6>,cluster.nodes=7,cluster.init=false,cluster.update.addNodes=true,cluster.update.newExternalIPs[0]=<load-balancerip-6>" bitnami/redis-cluster

Note we are providing the new IPs at cluster.update.newExternalIPs, the flag cluster.update.addNodes=true to enable the creation of the Job that adds a new node and now we are setting the LoadBalancerIP of the new service instead of leave it empty.

NOTE: To avoid the creation of the Job that initializes the Redis Cluster again, you will need to provide cluster.init=false.

Scale down the cluster

To scale down the redis cluster just perform a normal upgrade setting the cluster.nodes value to the desired number of nodes. It should not be less than 6. Also it is needed to provide the password using the password. For example, having more than 6 nodes, to scale down the cluster to 6 nodes:

helm upgrade --timeout 600s <release> --set "password=${REDIS_PASSWORD},cluster.nodes=6" .

The cluster will continue working during the update as long as the quorum is not lost.

NOTE: To avoid the creation of the Job that initializes the Redis Cluster again, you will need to provide cluster.init=false.

Using password file

To use a password file for Redis you need to create a secret containing the password.

Note

: It is important that the file with the password must be called redis-password

And then deploy the Helm Chart using the secret name as parameter:

usePassword=true
usePasswordFile=true
existingSecret=redis-password-secret
metrics.enabled=true

Securing traffic using TLS

TLS support can be enabled in the chart by specifying the tls. parameters while creating a release. The following parameters should be configured to properly enable the TLS support in the cluster:

• tls.enabled: Enable TLS support. Defaults to false
• tls.certificatesSecret: Name of the secret that contains the certificates. No defaults.
• tls.certFilename: Certificate filename. No defaults.
• tls.certKeyFilename: Certificate key filename. No defaults.
• tls.certCAFilename: CA Certificate filename. No defaults.

For example:

First, create the secret with the cetificates files:

kubectl create secret generic certificates-tls-secret --from-file=./cert.pem --from-file=./cert.key --from-file=./ca.pem

Then, use the following parameters:

tls.enabled="true"
tls.certificatesSecret="certificates-tls-secret"
tls.certFilename="cert.pem"
tls.certKeyFilename="cert.key"
tls.certCAFilename="ca.pem"

Note TLS and Prometheus Metrics: Current version of Redis Metrics Exporter (v1.6.1 at the time of writing) does not fully support the use of TLS. By enabling both features, the metric reporting pod may not work as expected. See Redis Metrics Exporter issue 387 for more information.

Sidecars and Init Containers

If you have a need for additional containers to run within the same pod as Redis (e.g. an additional metrics or logging exporter), you can do so via the sidecars config parameter. Simply define your container according to the Kubernetes container spec.

sidecars:
  - name: your-image-name
    image: your-image
    imagePullPolicy: Always
    ports:
      - name: portname
       containerPort: 1234

Similarly, you can add extra init containers using the initContainers parameter.

initContainers:
  - name: your-image-name
    image: your-image
    imagePullPolicy: Always
    ports:
      - name: portname
        containerPort: 1234

Adding extra environment variables

In case you want to add extra environment variables (useful for advanced operations like custom init scripts), you can use the extraEnvVars property.

extraEnvVars:
  - name: REDIS_WHATEVER
    value: value

Alternatively, you can use a ConfigMap or a Secret with the environment variables. To do so, use the extraEnvVarsCM or the extraEnvVarsSecret values.

Metrics

The chart optionally can start a metrics exporter for prometheus. The metrics endpoint (port 9121) is exposed in the service. Metrics can be scraped from within the cluster using something similar as the described in the example Prometheus scrape configuration. If metrics are to be scraped from outside the cluster, the Kubernetes API proxy can be utilized to access the endpoint.

Host Kernel Settings

Redis may require some changes in the kernel of the host machine to work as expected, in particular increasing the somaxconn value and disabling transparent huge pages. To do so, you can set up a privileged initContainer with the sysctlImage config values, for example:

sysctlImage:
  enabled: true
  mountHostSys: true
  command:
    - /bin/sh
    - -c
    - |-
      install_packages procps
      sysctl -w net.core.somaxconn=10000
      echo never > /host-sys/kernel/mm/transparent_hugepage/enabled

Alternatively, for Kubernetes 1.12+ you can set podSecurityContext.sysctls which will configure sysctls for master and slave pods. Example:

podSecurityContext:
  sysctls:
  - name: net.core.somaxconn
    value: "10000"

Note that this will not disable transparent huge tables.

Helm Upgrade

By default cluster.init will be set to true in order to initialize the Redis Cluster in the first installation. If for testing purposes you only want to deploy or upgrade the nodes but avoiding the creation of the cluster you can set cluster.init to false.

Persistence

By default, the chart mounts a Persistent Volume at the /bitnami path. The volume is created using dynamic volume provisioning.

NetworkPolicy

To enable network policy for Redis, install a networking plugin that implements the Kubernetes NetworkPolicy spec, and set networkPolicy.enabled to true.

For Kubernetes v1.5 & v1.6, you must also turn on NetworkPolicy by setting the DefaultDeny namespace annotation. Note: this will enforce policy for all pods in the namespace:

kubectl annotate namespace default "net.beta.kubernetes.io/network-policy={\"ingress\":{\"isolation\":\"DefaultDeny\"}}"

With NetworkPolicy enabled, only pods with the generated client label will be able to connect to Redis. This label will be displayed in the output after a successful install.

With networkPolicy.ingressNSMatchLabels pods from other namespaces can connect to redis. Set networkPolicy.ingressNSPodMatchLabels to match pod labels in matched namespace. For example, for a namespace labeled redis=external and pods in that namespace labeled redis-client=true the fields should be set:

networkPolicy:
  enabled: true
  ingressNSMatchLabels:
    redis: external
  ingressNSPodMatchLabels:
    redis-client: true

Notable changes

3.0.0

This version of the chart adapts the chart to the most recent Bitnami best practices and standards. Most of the Redis parameters were moved to the redis values section (such as extraEnvVars, sidecars, and so on). No major issues are expected during the upgrade.

2.0.0

The version 1.0.0 was using a label in the Statefulset's volumeClaimTemplate that didn't allow to upgrade the chart. The version 2.0.0 fixed that issue. Also it adds more docs in the README.md.