# Redis

[Redis](http://redis.io/) 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

```bash
# Testing configuration
$ helm install stable/redis
```

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

## Introduction

This chart bootstraps a [Redis](https://github.com/bitnami/bitnami-docker-redis) deployment on a [Kubernetes](http://kubernetes.io) cluster using the [Helm](https://helm.sh) package manager.

Bitnami charts can be used with [Kubeapps](https://kubeapps.com/) 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](https://kubeprod.io/).

## Prerequisites

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

## Installing the Chart

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

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

The command deploys Redis on the Kubernetes cluster in the default configuration. The [configuration](#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:

```bash
$ helm delete my-release
```

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

## Upgrading an existing Release to a new major version

A major chart version change (like v1.2.3 -> v2.0.0) indicates that there is an
incompatible breaking change needing manual actions.

### 5.0.0

The default image in this release may be switched out for any image containing the `redis-server`
and `redis-cli` binaries. If `redis-server` is not the default image ENTRYPOINT, `master.command`
must be specified.

#### Breaking changes
- `master.args` and `slave.args` are removed. Use `master.command` or `slave.command` instead in order to override the image entrypoint, or `master.extraFlags` to pass additional flags to `redis-server`.
- `disableCommands` is now interpreted as an array of strings instead of a string of comma separated values.
- `master.persistence.path` now defaults to `/data`.

### 4.0.0

This version removes the `chart` label from the `spec.selector.matchLabels`
which is immutable since `StatefulSet apps/v1beta2`. It has been inadvertently
added, causing any subsequent upgrade to fail. See https://github.com/helm/charts/issues/7726.

It also fixes https://github.com/helm/charts/issues/7726 where a deployment `extensions/v1beta1` can not be upgraded if `spec.selector` is not explicitly set.

Finally, it fixes https://github.com/helm/charts/issues/7803 by removing mutable labels in `spec.VolumeClaimTemplate.metadata.labels` so that it is upgradable.

In order to upgrade, delete the Redis StatefulSet before upgrading:
```bash
$ kubectl delete statefulsets.apps --cascade=false my-release-redis-master
```
And edit the Redis slave (and metrics if enabled) deployment:
```bash
kubectl patch deployments my-release-redis-slave --type=json -p='[{"op": "remove", "path": "/spec/selector/matchLabels/chart"}]'
kubectl patch deployments my-release-redis-metrics --type=json -p='[{"op": "remove", "path": "/spec/selector/matchLabels/chart"}]'
```

## Configuration

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

| Parameter                                  | Description                                                                                                    | Default                                              |
|--------------------------------------------|----------------------------------------------------------------------------------------------------------------|------------------------------------------------------|
| `global.imageRegistry`                     | Global Docker image registry                                                                                   | `nil`                                                |
| `image.registry`                           | Redis Image registry                                                                                           | `docker.io`                                          |
| `image.repository`                         | Redis Image name                                                                                               | `bitnami/redis`                                      |
| `image.tag`                                | Redis Image tag                                                                                                | `{VERSION}`                                          |
| `image.pullPolicy`                         | Image pull policy                                                                                              | `Always`                                             |
| `image.pullSecrets`                        | Specify docker-registry secret names as an array                                                               | `nil`                                                |
| `cluster.enabled`                          | Use master-slave topology                                                                                      | `true`                                               |
| `cluster.slaveCount`                       | Number of slaves                                                                                               | `1`                                                  |
| `existingSecret`                           | Name of existing secret object (for password authentication)                                                   | `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`                                | Redis configuration file to be used                                                                            | `nil`                                                |
| `networkPolicy.enabled`                    | Enable NetworkPolicy                                                                                           | `false`                                              |
| `networkPolicy.allowExternal`              | Don't require client label for connections                                                                     | `true`                                               |
| `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                                                                                                | `[]`                                                 |
| `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                                                                                      | `oliver006/redis_exporter`                           |
| `metrics.image.tag`                        | Redis exporter image tag                                                                                       | `v0.20.2`                                            |
| `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](https://github.com/oliver006/redis_exporter#flags)      | {}                                                   |
| `metrics.podLabels`                        | Additional labels for Metrics exporter pod                                                                     | {}                                                   |
| `metrics.podAnnotations`                   | Additional annotations for Metrics exporter pod                                                                | {}                                                   |
| `metrics.service.type`                     | Kubernetes Service type (redis metrics)                                                                        | `ClusterIP`                                          |
| `metrics.service.annotations`              | Annotations for the services to monitor  (redis master and redis slave service)                                | {}                                                   |
| `metrics.service.loadBalancerIP`           | loadBalancerIP if redis metrics service type is `LoadBalancer`                                                 | `nil`                                                |
| `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.serviceMonitor.selector`          | Default to kube-prometheus install (CoreOS recommended), but should be set according to Prometheus install     | `{ prometheus: kube-prometheus }`                    |
| `metrics.priorityClassName`                | Metrics exporter pod priorityClassName                                                                         | {}                                                   |
| `persistence.existingClaim`                | Provide an existing PersistentVolumeClaim                                                                      | `nil`                                                |
| `master.persistence.enabled`               | Use a PVC to persist data (master node)                                                                        | `true`                                               |
| `master.persistence.path`                  | Path to mount the volume at, to use other images                                                               | `/data`                                              |
| `master.persistence.subPath`               | Subdirectory of the volume to mount at                                                                         | `""`                                                 |
| `master.persistence.storageClass`          | Storage class of backing PVC                                                                                   | `generic`                                            |
| `master.persistence.accessModes`           | Persistent Volume Access Modes                                                                                 | `[ReadWriteOnce]`                                    |
| `master.persistence.size`                  | Size of data volume                                                                                            | `8Gi`                                                |
| `master.statefulset.updateStrategy`        | Update strategy for StatefulSet                                                                                | onDelete                                             |
| `master.statefulset.rollingUpdatePartition`| Partition update strategy                                                                                      | `nil`                                                |
| `master.podLabels`                         | Additional labels for Redis master pod                                                                         | {}                                                   |
| `master.podAnnotations`                    | Additional annotations for Redis master pod                                                                    | {}                                                   |
| `master.port`                              | Redis master port                                                                                              | `6379`                                               |
| `master.command`                           | Redis master entrypoint string. The command `redis-server` is executed if this is not provided.                  | `/run.sh`                                                   |
| `master.disableCommands`                   | Array of Redis commands to disable (master)                                                                    | `["FLUSHDB", "FLUSHALL"]`                                   |
| `master.extraFlags`                        | Redis master additional command line flags                                                                     | []                                                   |
| `master.nodeSelector`                      | Redis master Node labels for pod assignment                                                                    | {"beta.kubernetes.io/arch": "amd64"}                 |
| `master.tolerations`                       | Toleration labels for Redis master pod assignment                                                              | []                                                   |
| `master.affinity`                          | Affinity settings for Redis master pod assignment                                                              | {}                                                   |
| `master.schedulerName`                     | Name of an alternate scheduler                                                                                 | `nil`                                                |
| `master.service.type`                      | Kubernetes Service type (redis master)                                                                         | `ClusterIP`                                          |
| `master.service.port`                      | Kubernetes Service port (redis master)                                                                         | `6379`                                               |
| `master.service.nodePort`                  | Kubernetes Service nodePort (redis master)                                                                     | `nil`                                                |
| `master.service.annotations`               | annotations for redis master service                                                                           | {}                                                   |
| `master.service.loadBalancerIP`            | loadBalancerIP if redis master service type is `LoadBalancer`                                                  | `nil`                                                |
| `master.securityContext.enabled`           | Enable security context (redis master pod)                                                                     | `true`                                               |
| `master.securityContext.fsGroup`           | Group ID for the container (redis master pod)                                                                  | `1001`                                               |
| `master.securityContext.runAsUser`         | User ID for the container (redis master pod)                                                                   | `1001`                                               |
| `master.resources`                         | Redis master CPU/Memory resource requests/limits                                                               | Memory: `256Mi`, CPU: `100m`                         |
| `master.livenessProbe.enabled`             | Turn on and off liveness probe (redis master pod)                                                              | `true`                                               |
| `master.livenessProbe.initialDelaySeconds` | Delay before liveness probe is initiated (redis master pod)                                                    | `30`                                                 |
| `master.livenessProbe.periodSeconds`       | How often to perform the probe (redis master pod)                                                              | `30`                                                 |
| `master.livenessProbe.timeoutSeconds`      | When the probe times out (redis master pod)                                                                    | `5`                                                  |
| `master.livenessProbe.successThreshold`    | Minimum consecutive successes for the probe to be considered successful after having failed (redis master pod) | `1`                                                  |
| `master.livenessProbe.failureThreshold`    | Minimum consecutive failures for the probe to be considered failed after having succeeded.                     | `5`                                                  |
| `master.readinessProbe.enabled`            | Turn on and off readiness probe (redis master pod)                                                             | `true`                                               |
| `master.readinessProbe.initialDelaySeconds`| Delay before readiness probe is initiated (redis master pod)                                                   | `5`                                                  |
| `master.readinessProbe.periodSeconds`      | How often to perform the probe (redis master pod)                                                              | `10`                                                 |
| `master.readinessProbe.timeoutSeconds`     | When the probe times out (redis master pod)                                                                    | `1`                                                  |
| `master.readinessProbe.successThreshold`   | Minimum consecutive successes for the probe to be considered successful after having failed (redis master pod) | `1`                                                  |
| `master.readinessProbe.failureThreshold`   | Minimum consecutive failures for the probe to be considered failed after having succeeded.                     | `5`                                                  |
| `master.priorityClassName`                 | Redis Master pod priorityClassName                                                                             | {}                                                   |
| `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                                                                    | `latest`                                             |
| `volumePermissions.image.pullPolicy`       | Init container volume-permissions image pull policy                                                            | `IfNotPresent`                                       |
| `slave.service.type`                       | Kubernetes Service type (redis slave)                                                                          | `ClusterIP`                                          |
| `slave.service.nodePort`                   | Kubernetes Service nodePort (redis slave)                                                                      | `nil`                                                |
| `slave.service.annotations`                | annotations for redis slave service                                                                            | {}                                                   |
| `slave.service.loadBalancerIP`             | LoadBalancerIP if Redis slave service type is `LoadBalancer`                                                   | `nil`                                                |
| `slave.port`                               | Redis slave port                                                                                               | `master.port`                                        |
| `slave.command`                            | Redis slave entrypoint array. The docker image's ENTRYPOINT is used if this is not provided.                   | `master.command`                                     |
| `slave.disableCommands`                    | Array of Redis commands to disable (slave)                                                                     | `master.disableCommands`                             |
| `slave.extraFlags`                         | Redis slave additional command line flags                                                                      | `master.extraFlags`                                  |
| `slave.livenessProbe.enabled`              | Turn on and off liveness probe (redis slave pod)                                                               | `master.livenessProbe.enabled`                       |
| `slave.livenessProbe.initialDelaySeconds`  | Delay before liveness probe is initiated (redis slave pod)                                                     | `master.livenessProbe.initialDelaySeconds`           |
| `slave.livenessProbe.periodSeconds`        | How often to perform the probe (redis slave pod)                                                               | `master.livenessProbe.periodSeconds`                 |
| `slave.livenessProbe.timeoutSeconds`       | When the probe times out (redis slave pod)                                                                     | `master.livenessProbe.timeoutSeconds`                |
| `slave.livenessProbe.successThreshold`     | Minimum consecutive successes for the probe to be considered successful after having failed (redis slave pod)  | `master.livenessProbe.successThreshold`              |
| `slave.livenessProbe.failureThreshold`     | Minimum consecutive failures for the probe to be considered failed after having succeeded.                     | `master.livenessProbe.failureThreshold`              |
| `slave.readinessProbe.enabled`             | Turn on and off slave.readiness probe (redis slave pod)                                                        | `master.readinessProbe.enabled`                      |
| `slave.readinessProbe.initialDelaySeconds` | Delay before slave.readiness probe is initiated (redis slave pod)                                              | `master.readinessProbe.initialDelaySeconds`          |
| `slave.readinessProbe.periodSeconds`       | How often to perform the probe (redis slave pod)                                                               | `master.readinessProbe.periodSeconds`                |
| `slave.readinessProbe.timeoutSeconds`      | When the probe times out (redis slave pod)                                                                     | `master.readinessProbe.timeoutSeconds`               |
| `slave.readinessProbe.successThreshold`    | Minimum consecutive successes for the probe to be considered successful after having failed (redis slave pod)  | `master.readinessProbe.successThreshold`             |
| `slave.readinessProbe.failureThreshold`    | Minimum consecutive failures for the probe to be considered failed after having succeeded. (redis slave pod)   | `master.readinessProbe.failureThreshold`             |
| `slave.podLabels`                          | Additional labels for Redis slave pod                                                                          | `master.podLabels`                                   |
| `slave.podAnnotations`                     | Additional annotations for Redis slave pod                                                                     | `master.podAnnotations`                              |
| `slave.schedulerName`                      | Name of an alternate scheduler                                                                                 | `nil`                                                |
| `slave.securityContext.enabled`            | Enable security context (redis slave pod)                                                                      | `master.securityContext.enabled`                     |
| `slave.securityContext.fsGroup`            | Group ID for the container (redis slave pod)                                                                   | `master.securityContext.fsGroup`                     |
| `slave.securityContext.runAsUser`          | User ID for the container (redis slave pod)                                                                    | `master.securityContext.runAsUser`                   |
| `slave.resources`                          | Redis slave CPU/Memory resource requests/limits                                                                | `master.resources`                                   |
| `slave.affinity`                           | Enable node/pod affinity for slaves                                                                            | {}                                                   |
| `slave.priorityClassName`                  | Redis Slave pod priorityClassName                                                                              | {}                                                   |
| `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                                                                                 | `latest`                                             |
| `sysctlImage.pullPolicy`                   | sysctlImage Init container pull policy                                                                         | `Always`                                             |
| `sysctlImage.mountHostSys`                 | Mount the host `/sys` folder to `/host-sys`                                                                    | `false`                                              |

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

```bash
$ 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,

```bash
$ helm install --name my-release -f values.yaml stable/redis
```

> **Tip**: You can use the default [values.yaml](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](https://github.com/kubernetes/minikube/issues/1990) for more information.

## NetworkPolicy

To enable network policy for Redis, install
[a networking plugin that implements the Kubernetes NetworkPolicy spec](https://kubernetes.io/docs/tasks/administer-cluster/declare-network-policy#before-you-begin),
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.

## Persistence

By default, the chart mounts a [Persistent Volume](http://kubernetes.io/docs/user-guide/persistent-volumes/) at the `/data` path. The volume is created using dynamic volume provisioning. If a Persistent Volume Claim already exists, specify it during installation.

### Existing PersistentVolumeClaim

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

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

## Metrics

The chart optionally can start a metrics exporter for [prometheus](https://prometheus.io). 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](https://github.com/prometheus/prometheus/blob/master/documentation/examples/prometheus-kubernetes.yml). 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 systemd
      sysctl -w net.core.somaxconn=10000
      echo never > /host-sys/kernel/mm/transparent_hugepage/enabled
```

## Upgrade

## To 6.0.0

Previous versions of the chart were using an init-container to change the permissions of the volumes. This was done in case the `securityContext` directive in the template was not enough for that (for example, with cephFS). In this new version of the chart, this container is disabled by default (which should not affect most of the deployments). If your installation still requires that init container, execute `helm upgrade` with the `--set volumePermissions.enabled=true`.
