# ⚠️ 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](https://github.com/helm/charts#%EF%B8%8F-deprecation-and-archive-notice), and [Update](https://helm.sh/blog/charts-repo-deprecation/).

# Redis

----------------------------------------
# Deprecation Warning
*As part of the [deprecation timeline](https://github.com/helm/charts/#deprecation-timeline). We will move this to an official repository [here](https://github.com/DandyDeveloper/charts)*

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](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
$ 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](https://redis.io) highly available master/slave statefulset in a [Kubernetes](http://kubernetes.io) 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](https://hub.docker.com/_/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](https://github.com/haproxy/haproxy/tree/master/contrib/prometheus-exporter), 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

```bash
$ 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](#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:

```bash
$ 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,

```bash
$ 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,

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

> **Tip**: You can use the default [values.yaml](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](http://download.redis.io/redis-stable/redis.conf)
[Example sentinel.conf](http://download.redis.io/redis-stable/sentinel.conf)

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

```yml
    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:

```yml
    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.
