stable/redis-ha

Chart version: 4.4.6
Api version: v1
App version: 5.0.6
DEPRECATED - Highly available Kubernetes implementation of Redis
application
Chart Type
DEPRECATED
Status
Unknown
License
19467
Downloads
https://charts.helm.sh/stable
Set me up:
helm repo add center https://repo.chartcenter.io
Install Chart:
helm install redis-ha center/stable/redis-ha
Versions (0)

⚠️ Repo Archive Notice

As of Nov 13, 2020, charts in this repo will no longer be updated. For more information, see the Helm Charts Deprecation and Archive Notice, and Update.

Redis


Deprecation Warning

As part of the deprecation timeline. We will move this to an official repository here

Please make PRs / Issues here from now on

We will keep the changes in sync as best we can, but we will be notifying people to submit PRs here from now on instead. If you have any questions, feel free to get in touch with either of the maintainers.

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;

$ helm install stable/redis-ha

By default this chart install 3 pods total: * one pod containing a redis master and sentinel container (optional prometheus metrics exporter sidecar available) * two pods each containing a redis slave and sentinel containers (optional prometheus metrics exporter sidecars available)

Introduction

This chart bootstraps a Redis highly available master/slave statefulset in a Kubernetes cluster using the Helm package manager.

Prerequisites

  • Kubernetes 1.8+ with Beta APIs enabled
  • PV provisioner support in the underlying infrastructure

Upgrading the Chart

Please note that there have been a number of changes simplifying the redis management strategy (for better failover and elections) in the 3.x version of this chart. These changes allow the use of official redis images that do not require special RBAC or ServiceAccount roles. As a result when upgrading from version >=2.0.1 to >=3.0.0 of this chart, Role, RoleBinding, and ServiceAccount resources should be deleted manually.

Upgrading the chart from 3.x to 4.x

Starting from version 4.x HAProxy sidecar prometheus-exporter removed and replaced by the embedded HAProxy metrics endpoint, as a result when upgrading from version 3.x to 4.x section haproxy.exporter should be removed and the haproxy.metrics need to be configured for fit your needs.

Installing the Chart

To install the chart

$ helm install stable/redis-ha

The command deploys Redis on the Kubernetes cluster in the default configuration. By default this chart install one master pod containing redis master container and sentinel container along with 2 redis slave pods each containing their own sentinel sidecars. 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 deployment:

$ helm delete <chart-name>

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

Configuration

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

Parameter Description Default
image Redis image redis
imagePullSecrets Reference to one or more secrets to be used when pulling redis images []
tag Redis tag 5.0.6-alpine
replicas Number of redis master/slave pods 3
serviceAccount.create Specifies whether a ServiceAccount should be created true
serviceAccount.name The name of the ServiceAccount to create Generated using the redis-ha.fullname template
rbac.create Create and use RBAC resources true
redis.port Port to access the redis service 6379
redis.masterGroupName Redis convention for naming the cluster group: must match ^[\\w-\\.]+$ and can be templated mymaster
redis.config Any valid redis config options in this section will be applied to each server (see below) see values.yaml
redis.customConfig Allows for custom redis.conf files to be applied. If this is used then redis.config is ignored
redis.resources CPU/Memory for master/slave nodes resource requests/limits {}
sentinel.port Port to access the sentinel service 26379
sentinel.quorum Minimum number of servers necessary to maintain quorum 2
sentinel.config Valid sentinel config options in this section will be applied as config options to each sentinel (see below) see values.yaml
sentinel.customConfig Allows for custom sentinel.conf files to be applied. If this is used then sentinel.config is ignored
sentinel.resources CPU/Memory for sentinel node resource requests/limits {}
init.resources CPU/Memory for init Container node resource requests/limits {}
auth Enables or disables redis AUTH (Requires redisPassword to be set) false
redisPassword A password that configures a requirepass and masterauth in the conf parameters (Requires auth: enabled)
authKey The key holding the redis password in an existing secret. auth
existingSecret An existing secret containing a key defined by authKey that configures requirepass and masterauth in the conf parameters (Requires auth: enabled, cannot be used in conjunction with .Values.redisPassword)
nodeSelector Node labels for pod assignment {}
tolerations Toleration labels for pod assignment []
hardAntiAffinity Whether the Redis server pods should be forced to run on separate nodes. true
additionalAffinities Additional affinities to add to the Redis server pods. {}
securityContext Security context to be added to the Redis server pods. {runAsUser: 1000, fsGroup: 1000, runAsNonRoot: true}
affinity Override all other affinity settings with a string. ""
persistentVolume.size Size for the volume 10Gi
persistentVolume.annotations Annotations for the volume {}
persistentVolume.reclaimPolicy Method used to reclaim an obsoleted volume. Delete or Retain ""
emptyDir Configuration of emptyDir, used only if persistentVolume is disabled and no hostPath specified {}
exporter.enabled If true, the prometheus exporter sidecar is enabled false
exporter.image Exporter image oliver006/redis_exporter
exporter.tag Exporter tag v0.31.0
exporter.port Exporter port 9121
exporter.annotations Prometheus scrape annotations {prometheus.io/path: /metrics, prometheus.io/port: "9121", prometheus.io/scrape: "true"}
exporter.extraArgs Additional args for the exporter {}
exporter.script A custom custom Lua script that will be mounted to exporter for collection of custom metrics. Creates a ConfigMap and sets env var REDIS_EXPORTER_SCRIPT.
exporter.serviceMonitor.enabled Use servicemonitor from prometheus operator false
exporter.serviceMonitor.namespace Namespace the service monitor is created in default
exporter.serviceMonitor.interval Scrape interval, If not set, the Prometheus default scrape interval is used nil
exporter.serviceMonitor.telemetryPath Path to redis-exporter telemetry-path /metrics
exporter.serviceMonitor.labels Labels for the servicemonitor passed to Prometheus Operator {}
exporter.serviceMonitor.timeout How long until a scrape request times out. If not set, the Prometheus default scape timeout is used nil
haproxy.enabled Enabled HAProxy LoadBalancing/Proxy false
haproxy.replicas Number of HAProxy instances 3
haproxy.image.repository HAProxy Image Repository haproxy
haproxy.image.tag HAProxy Image Tag 2.0.1
haproxy.image.pullPolicy HAProxy Image PullPolicy IfNotPresent
haproxy.imagePullSecrets Reference to one or more secrets to be used when pulling haproxy images []
haproxy.annotations HAProxy template annotations {}
haproxy.customConfig Allows for custom config-haproxy.cfg file to be applied. If this is used then default config will be overwriten
haproxy.extraConfig Allows to place any additional configuration section to add to the default config-haproxy.cfg
haproxy.resources HAProxy resources {}
haproxy.emptyDir Configuration of emptyDir {}
haproxy.service.type HAProxy service type “ClusterIP”, “LoadBalancer” or “NodePort” ClusterIP
haproxy.service.nodePort HAProxy service nodePort value (haproxy.service.type must be NodePort) not set
haproxy.service.annotations HAProxy service annotations {}
haproxy.stickyBalancing HAProxy sticky load balancing to Redis nodes. Helps with connections shutdown. false
haproxy.hapreadport.enable Enable a read only port for redis slaves false
haproxy.hapreadport.port Haproxy port for read only redis slaves 6380
haproxy.metrics.enabled HAProxy enable prometheus metric scraping false
haproxy.metrics.port HAProxy prometheus metrics scraping port 9101
haproxy.metrics.portName HAProxy metrics scraping port name exporter-port
haproxy.metrics.scrapePath HAProxy prometheus metrics scraping port /metrics
haproxy.metrics.serviceMonitor.enabled Use servicemonitor from prometheus operator for HAProxy metrics false
haproxy.metrics.serviceMonitor.namespace Namespace the service monitor for HAProxy metrics is created in default
haproxy.metrics.serviceMonitor.interval Scrape interval, If not set, the Prometheus default scrape interval is used nil
haproxy.metrics.serviceMonitor.telemetryPath Path to HAProxy metrics telemetry-path /metrics
haproxy.metrics.serviceMonitor.labels Labels for the HAProxy metrics servicemonitor passed to Prometheus Operator {}
haproxy.metrics.serviceMonitor.timeout How long until a scrape request times out. If not set, the Prometheus default scape timeout is used nil
haproxy.init.resources Extra init resources {}
haproxy.timeout.connect haproxy.cfg timeout connect setting 4s
haproxy.timeout.server haproxy.cfg timeout server setting 30s
haproxy.timeout.client haproxy.cfg timeout client setting 30s
haproxy.timeout.check haproxy.cfg timeout check setting 2s
haproxy.priorityClassName priorityClassName for haproxy deployment not set
haproxy.securityContext Security context to be added to the HAProxy deployment. {runAsUser: 1000, fsGroup: 1000, runAsNonRoot: true}
haproxy.hardAntiAffinity Whether the haproxy pods should be forced to run on separate nodes. true
haproxy.affinity Override all other haproxy affinity settings with a string. ""
haproxy.additionalAffinities Additional affinities to add to the haproxy server pods. {}
podDisruptionBudget Pod Disruption Budget rules {}
priorityClassName priorityClassName for redis-ha-statefulset not set
hostPath.path Use this path on the host for data storage not set
hostPath.chown Run an init-container as root to set ownership on the hostPath true
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 busybox
sysctlImage.tag sysctlImage Init container tag 1.31.1
sysctlImage.pullPolicy sysctlImage Init container pull policy Always
sysctlImage.mountHostSys Mount the host /sys folder to /host-sys false
sysctlImage.resources sysctlImage resources {}
schedulerName Alternate scheduler name nil

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

$ helm install \
  --set image=redis \
  --set tag=5.0.5-alpine \
    stable/redis-ha

The above command sets the Redis server within default namespace.

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

$ helm install -f values.yaml stable/redis-ha

Tip: You can use the default values.yaml

Custom Redis and Sentinel config options

This chart allows for most redis or sentinel config options to be passed as a key value pair through the values.yaml under redis.config and sentinel.config. See links below for all available options.

Example redis.conf Example sentinel.conf

For example repl-timeout 60 would be added to the redis.config section of the values.yaml as:

    repl-timeout: "60"

Note:

  1. Some config options should be renamed by redis version,e.g.: # In redis 5.x,see https://raw.githubusercontent.com/antirez/redis/5.0/redis.conf min-replicas-to-write: 1 min-replicas-max-lag: 5 # In redis 4.x and redis 3.x,see https://raw.githubusercontent.com/antirez/redis/4.0/redis.conf and https://raw.githubusercontent.com/antirez/redis/3.0/redis.conf min-slaves-to-write 1 min-slaves-max-lag 5

Sentinel options supported must be in the the sentinel <option> <master-group-name> <value> format. For example, sentinel down-after-milliseconds 30000 would be added to the sentinel.config section of the values.yaml as:

    down-after-milliseconds: 30000

If more control is needed from either the redis or sentinel config then an entire config can be defined under redis.customConfig or sentinel.customConfig. Please note that these values will override any configuration options under their respective section. For example, if you define sentinel.customConfig then the sentinel.config is ignored.

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
    - -xc
    - |-
      sysctl -w net.core.somaxconn=10000
      echo never > /host-sys/kernel/mm/transparent_hugepage/enabled

HAProxy startup

When HAProxy is enabled, it will attempt to connect to each announce-service of each redis replica instance in its init container before starting. It will fail if announce-service IP is not available fast enough (10 seconds max by announce-service). A such case could happen if the orchestator is pending the nomination of redis pods. Risk is limited because announce-service is using publishNotReadyAddresses: true, although, in such case, HAProxy pod will be rescheduled afterward by the orchestrator.