bitnami/memcached

Chart version: 5.4.5
Api version: v2
App version: 1.6.9
Chart for Memcached
application
Chart Type
Active
Status
Unknown
License
21107
Downloads
https://charts.bitnami.com/bitnami
Set me up:
helm repo add center https://repo.chartcenter.io
Install Chart:
helm install memcached center/bitnami/memcached
Versions (0)

Memcached

Memcached is an in-memory key-value store for small chunks of arbitrary data (strings, objects) from results of database calls, API calls, or page rendering.

TL;DR

$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/memcached

Introduction

This chart bootstraps a Memcached 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 Helm chart has been tested on top of Bitnami Kubernetes Production Runtime (BKPR). Deploy BKPR to get automated TLS certificates, logging and monitoring for your applications.

Prerequisites

  • Kubernetes 1.12+
  • Helm 3.1.0

Installing the Chart

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

$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/memcached

These commands deploy Memcached on the Kubernetes cluster in the default configuration. The Parameters 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.

Parameters

The following tables lists the configurable parameters of the Memcached chart and their default values.

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)
image.registry Memcached image registry docker.io
image.repository Memcached Image name bitnami/memcached
image.tag Memcached Image tag {TAG_NAME}
image.pullPolicy Memcached image pull policy IfNotPresent
image.pullSecrets Specify docker-registry secret names as an array [] (does not add image pull secrets to deployed pods)
nameOverride String to partially override common.names.fullname template with a string nil
fullnameOverride String to fully override common.names.fullname template with a string nil
clusterDomain Kubernetes cluster domain cluster.local
architecture Memcached architecture. Allowed values: standalone or high-availability standalone
replicaCount Number of containers 1
extraEnv Additional env vars to pass {}
arguments Arguments to pass ["/run.sh"]
memcachedUsername Memcached admin user nil
memcachedPassword Memcached admin password nil
service.type Kubernetes service type for Memcached ClusterIP
service.port Memcached service port 11211
service.clusterIP Specific cluster IP when service type is cluster IP. Use None for headless service nil
service.nodePort Kubernetes Service nodePort nil
service.loadBalancerIP loadBalancerIP if service type is LoadBalancer nil
service.annotations Additional annotations for Memcached service {}
resources.requests CPU/Memory resource requests {memory: "256Mi", cpu: "250m"}
resources.limits CPU/Memory resource limits {}
persistence.enabled Enable persistence using PVC (Requires architecture: “high-availability”) true
persistence.storageClass PVC Storage Class for Memcached volume nil (uses alpha storage class annotation)
persistence.accessMode PVC Access Mode for Memcached volume ReadWriteOnce
persistence.size PVC Storage Request for Memcached volume 8Gi
securityContext.enabled Enable security context true
securityContext.fsGroup Group ID for the container 1001
securityContext.runAsUser User ID for the container 1001
securityContext.readOnlyRootFilesystem Enable read-only filesystem false
podAnnotations Pod annotations {}
podAffinityPreset Pod affinity preset. Ignored if affinity is set. Allowed values: soft or hard ""
podAntiAffinityPreset Pod anti-affinity preset. Ignored if affinity is set. Allowed values: soft or hard soft
nodeAffinityPreset.type Node affinity preset type. Ignored if affinity is set. Allowed values: soft or hard ""
nodeAffinityPreset.key Node label key to match. Ignored if affinity is set. ""
nodeAffinityPreset.values Node label values to match. Ignored if affinity is set. []
affinity Affinity for pod assignment {} (evaluated as a template)
nodeSelector Node labels for pod assignment {} (evaluated as a template)
tolerations Tolerations for pod assignment [] (evaluated as a template)
priorityClassName Controller priorityClassName nil
metrics.enabled Start a side-car prometheus exporter false
metrics.image.registry Memcached exporter image registry docker.io
metrics.image.repository Memcached exporter image name bitnami/memcached-exporter
metrics.image.tag Memcached exporter image tag {TAG_NAME}
metrics.image.pullPolicy Image pull policy IfNotPresent
metrics.image.pullSecrets Specify docker-registry secret names as an array [] (does not add image pull secrets to deployed pods)
metrics.podAnnotations Additional annotations for Metrics exporter {prometheus.io/scrape: "true", prometheus.io/port: "9150"}
metrics.resources Exporter resource requests/limit {}
metrics.service.type Kubernetes service type for Prometheus metrics ClusterIP
metrics.service.port Prometheus metrics service port 9150
metrics.service.annotations Prometheus exporter svc annotations {prometheus.io/scrape: "true", prometheus.io/port: "9150"}

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

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

$ helm install my-release --set memcachedUsername=user,memcachedPassword=password bitnami/memcached

The above command sets the Memcached admin account username and password to user and password respectively.

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/memcached

Tip: You can use the default values.yaml

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.

Persistence

When using architecture: "high-availability" the Bitnami Memcached image stores the cache-state at the /cache-state path of the container if enabled.

Persistent Volume Claims are used to keep the data across deployments. This is known to work in GCE, AWS, and minikube. See the Parameters section to configure the PVC or to disable persistence.

Setting Pod’s affinity

This chart allows you to set your custom affinity using the affinity parameter. Find more information about Pod’s affinity in the kubernetes documentation.

As an alternative, you can use of the preset configurations for pod affinity, pod anti-affinity, and node affinity available at the bitnami/common chart. To do so, set the podAffinityPreset, podAntiAffinityPreset, or nodeAffinityPreset parameters.

Troubleshooting

Find more information about how to deal with common errors related to Bitnami’s Helm charts in this troubleshooting guide.

Notable changes

4.0.0

Backwards compatibility is not guaranteed unless you modify the labels used on the chart’s deployments. Use the workaround below to upgrade from versions previous to 4.0.0. The following example assumes that the release name is memcached:

$ kubectl delete deployment  memcached --cascade=false
$ helm upgrade memcached bitnami/memcached

3.0.0

This release uses the new bash based bitnami/memcached container which uses bash scripts for the start up logic of the container and is smaller in size.

Upgrading

To 5.3.0

This version introduces bitnami/common, a library chart as a dependency. More documentation about this new utility could be found here. Please, make sure that you have updated the chart dependencies before executing any upgrade.

To 5.0.0

On November 13, 2020, Helm v2 support was formally finished, this major version is the result of the required changes applied to the Helm Chart to be able to incorporate the different features added in Helm v3 and to be consistent with the Helm project itself regarding the Helm v2 EOL.

What changes were introduced in this major version?

  • Previous versions of this Helm Chart use apiVersion: v1 (installable by both Helm 2 and 3), this Helm Chart was updated to apiVersion: v2 (installable by Helm 3 only). Here you can find more information about the apiVersion field.
  • The different fields present in the Chart.yaml file has been ordered alphabetically in a homogeneous way for all the Bitnami Helm Charts

Considerations when upgrading to this version

  • If you want to upgrade to this version from a previous one installed with Helm v3, you shouldn’t face any issues
  • If you want to upgrade to this version using Helm v2, this scenario is not supported as this version doesn’t support Helm v2 anymore
  • If you installed the previous version with Helm v2 and wants to upgrade to this version with Helm v3, please refer to the official Helm documentation about migrating from Helm v2 to v3

Useful links

To 1.0.0

Backwards compatibility is not guaranteed unless you modify the labels used on the chart’s deployments. Use the workaround below to upgrade from versions previous to 1.0.0. The following example assumes that the release name is memcached:

$ kubectl patch deployment memcached --type=json -p='[{"op": "remove", "path": "/spec/selector/matchLabels/chart"}]'