Redis

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 stable/redis

# Production configuration$ helm install stable/redis --values values-production.yaml

Introduction

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

Prerequisites

• Kubernetes 1.8+
• PV provisioner support in the underlying infrastructure

Installing the Chart

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

$ helm install --name my-release stable/redis

The command deploys Redis on the Kubernetes cluster in the default configuration. 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 my-release deployment:

$ helm delete my-release

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.

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

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

$ helm install --name my-release   --set password=secretpassword     stable/redis

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 --name my-release -f values.yaml stable/redis

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.

NetworkPolicy

To enable network policy for Redis, installa 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 settingthe 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 beable to connect to Redis. This label will be displayed in the outputafter a successful install.

Persistence

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

By default, the chart mounts a Persistent Volume at this location. The volume is created using dynamic volume provisioning. If a Persistent Volume Claim already exists, specify it during installation.

By default, the chart persists both data and configuration. If you wish to persist only the data directory set persistence.path to /bitnami/redis/data and persistence.subPath to redis/data.

Existing PersistentVolumeClaim

1. Create the PersistentVolume
2. Create the PersistentVolumeClaim
3. Install the chart

$ helm install --set persistence.existingClaim=PVC_NAME stable/redis

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.