Elasticsearch Helm Chart

This Helm chart is a lightweight way to configure and run our official Elasticsearch Docker image.

Warning When it comes to running the Elastic on Kubernetes infrastructure, we recommend Elastic Cloud on Kubernetes (ECK) as the best way to run and manage the Elastic Stack.

ECK offers many operational benefits for both our basic-tier and our enterprise-tier customers, such as spinning up cluster nodes that were lost on failed infrastructure, seamless upgrades, rolling cluster changes, and much much more.

With the release of the Elastic Stack Helm charts for Elastic version 8.5.1, we are handing over the ongoing maintenance of our Elastic Stack Helm charts to the community and contributors. This repository will finally be archived after 6 months time. Elastic Stacks deployed on Kubernetes through Helm charts will still be fully supported under EOL limitations.

Since we want to provide an even better experience for our customers by running the Elastic Stack on Kubernetes, we will continue maintaining the Helm charts applicable to ECK Custom Resources. These charts can be found in the ECK repository.

Helm charts will currently be maintained for ECK Enterprise-tier customers, however, we encourage the community to engage with the existing Helm charts for the Elastic Stack and continue supporting their ongoing maintenance.

See https://github.com/elastic/helm-charts/issues/1731 for more details.

• Requirements
• Installing
  • Install a released version using the Helm repository
  • Install a development version using the main branch
• Upgrading
• Usage notes
• Configuration
• FAQ
  • How to deploy this chart on a specific K8S distribution?
  • How to deploy dedicated nodes types?
    • Coordinating nodes
    • Clustering and Node Discovery
  • How to deploy clusters with security (authentication and TLS) enabled?
  • How to migrate from helm/charts stable chart?
  • How to install plugins?
  • How to use the keystore?
    • Basic example
    • Multiple keys
    • Custom paths and keys
  • How to enable snapshotting?
  • How to configure templates post-deployment?
• Contributing

Requirements

• Minimum cluster requirements include the following to run this chart with default settings. All of these settings are configurable.
  • Three Kubernetes nodes to respect the default "hard" affinity settings
  • 1GB of RAM for the JVM heap

See supported configurations for more details.

Installing

Install a released version using the Helm repository

• Add the Elastic Helm charts repo: helm repo add elastic https://helm.elastic.co

• Install it: helm install elasticsearch elastic/elasticsearch

Install a development version using the main branch

• Clone the git repo: git clone git@github.com:elastic/helm-charts.git

• Install it: helm install elasticsearch ./helm-charts/elasticsearch --set imageTag=8.5.1

Upgrading

Please always check CHANGELOG.md and BREAKING_CHANGES.md before upgrading to a new chart version.

Usage notes

• This repo includes several examples of configurations that can be used as a reference. They are also used in the automated testing of this chart.
• Automated testing of this chart is currently only run against GKE (Google Kubernetes Engine).
• The chart deploys a StatefulSet and by default will do an automated rolling update of your cluster. It does this by waiting for the cluster health to become green after each instance is updated. If you prefer to update manually you can set OnDelete updateStrategy.
• It is important to verify that the JVM heap size in esJavaOpts and to set the CPU/Memory resources to something suitable for your cluster.
• To simplify chart and maintenance each set of node groups is deployed as a separate Helm release. Take a look at the multi example to get an idea for how this works. Without doing this it isn't possible to resize persistent volumes in a StatefulSet. By setting it up this way it makes it possible to add more nodes with a new storage size then drain the old ones. It also solves the problem of allowing the user to determine which node groups to update first when doing upgrades or changes.
• We have designed this chart to be very un-opinionated about how to configure Elasticsearch. It exposes ways to set environment variables and mount secrets inside of the container. Doing this makes it much easier for this chart to support multiple versions with minimal changes.

Configuration

Parameter	Description	Default
antiAffinityTopologyKey	The anti-affinity topology key. By default this will prevent multiple Elasticsearch nodes from running on the same Kubernetes node	kubernetes.io/hostname
antiAffinity	Setting this to hard enforces the anti-affinity rules. If it is set to soft it will be done "best effort". Other values will be ignored	hard
clusterHealthCheckParams	The Elasticsearch cluster health status params that will be used by readiness probe command	wait_for_status=green&timeout=1s
clusterName	This will be used as the Elasticsearch cluster.name and should be unique per cluster in the namespace	elasticsearch
createCert	This will automatically create the SSL certificates	true
enableServiceLinks	Set to false to disabling service links, which can cause slow pod startup times when there are many services in the current namespace.	true
envFrom	Templatable string to be passed to the environment from variables which will be appended to the envFrom: definition for the container	[]
esConfig	Allows you to add any config files in /usr/share/elasticsearch/config/ such as elasticsearch.yml and log4j2.properties. See values.yaml for an example of the formatting	{}
esJavaOpts	Java options for Elasticsearch. This is where you could configure the jvm heap size	""
esJvmOptions	Java options for Elasticsearch. Override the default JVM options by adding custom options files . See values.yaml for an example of the formatting	{}
esMajorVersion	Deprecated. Instead, use the version of the chart corresponding to your ES minor version. Used to set major version specific configuration. If you are using a custom image and not running the default Elasticsearch version you will need to set this to the version you are running (e.g. esMajorVersion: 6)	""
extraContainers	Templatable string of additional containers to be passed to the tpl function	""
extraEnvs	Extra environment variables which will be appended to the env: definition for the container	[]
extraInitContainers	Templatable string of additional initContainers to be passed to the tpl function	""
extraVolumeMounts	Templatable string of additional volumeMounts to be passed to the tpl function	""
extraVolumes	Templatable string of additional volumes to be passed to the tpl function	""
fullnameOverride	Overrides the clusterName and nodeGroup when used in the naming of resources. This should only be used when using a single nodeGroup, otherwise you will have name conflicts	""
healthNameOverride	Overrides test-elasticsearch-health pod name	""
hostAliases	Configurable hostAliases	[]
httpPort	The http port that Kubernetes will use for the healthchecks and the service. If you change this you will also need to set http.port in extraEnvs	9200
imagePullPolicy	The Kubernetes imagePullPolicy value	IfNotPresent
imagePullSecrets	Configuration for imagePullSecrets so that you can use a private registry for your image	[]
imageTag	The Elasticsearch Docker image tag	8.5.1
image	The Elasticsearch Docker image	docker.elastic.co/elasticsearch/elasticsearch
ingress	Configurable ingress to expose the Elasticsearch service. See values.yaml for an example	see values.yaml
initResources	Allows you to set the resources for the initContainer in the StatefulSet	{}
keystore	Allows you map Kubernetes secrets into the keystore. See the config example and how to use the keystore	[]
labels	Configurable labels applied to all Elasticsearch pods	{}
lifecycle	Allows you to add lifecycle hooks. See values.yaml for an example of the formatting	{}
masterService	The service name used to connect to the masters. You only need to set this if your master nodeGroup is set to something other than master. See Clustering and Node Discovery for more information	""
maxUnavailable	The maxUnavailable value for the pod disruption budget. By default this will prevent Kubernetes from having more than 1 unhealthy pod in the node group	1
minimumMasterNodes	The value for discovery.zen.minimum_master_nodes. Should be set to (master_eligible_nodes / 2) + 1. Ignored in Elasticsearch versions >= 7	2
nameOverride	Overrides the clusterName when used in the naming of resources	""
networkHost	Value for the network.host Elasticsearch setting	0.0.0.0
networkPolicy	The NetworkPolicy to set. See values.yaml for an example	{http.enabled: false,transport.enabled: false}
nodeAffinity	Value for the node affinity settings	{}
nodeGroup	This is the name that will be used for each group of nodes in the cluster. The name will be clusterName-nodeGroup-X , nameOverride-nodeGroup-X if a nameOverride is specified, and fullnameOverride-X if a fullnameOverride is specified	master
nodeSelector	Configurable nodeSelector so that you can target specific nodes for your Elasticsearch cluster	{}
persistence	Enables a persistent volume for Elasticsearch data. Can be disabled for nodes that only have roles which don't require persistent data	see values.yaml
podAnnotations	Configurable annotations applied to all Elasticsearch pods	{}
podManagementPolicy	By default Kubernetes deploys StatefulSets serially. This deploys them in parallel so that they can discover each other	Parallel
podSecurityContext	Allows you to set the securityContext for the pod	see values.yaml
podSecurityPolicy	Configuration for create a pod security policy with minimal permissions to run this Helm chart with create: true. Also can be used to reference an external pod security policy with name: "externalPodSecurityPolicy"	see values.yaml
priorityClassName	The name of the PriorityClass. No default is supplied as the PriorityClass must be created first	""
protocol	The protocol that will be used for the readiness probe. Change this to https if you have xpack.security.http.ssl.enabled set	http
rbac	Configuration for creating a role, role binding and ServiceAccount as part of this Helm chart with create: true. Also can be used to reference an external ServiceAccount with serviceAccountName: "externalServiceAccountName", or automount the service account token	see values.yaml
readinessProbe	Configuration fields for the readiness probe	see values.yaml
replicas	Kubernetes replica count for the StatefulSet (i.e. how many pods)	3
resources	Allows you to set the resources for the StatefulSet	see values.yaml
roles	A list with the specific roles for the nodeGroup	see values.yaml
schedulerName	Name of the alternate scheduler	""
secret.enabled	Enable Secret creation for Elasticsearch credentials	true
secret.password	Initial password for the elastic user	"" (generated randomly)
secretMounts	Allows you easily mount a secret as a file inside the StatefulSet. Useful for mounting certificates and other secrets. See values.yaml for an example	[]
securityContext	Allows you to set the securityContext for the container	see values.yaml
service.annotations	LoadBalancer annotations that Kubernetes will use for the service. This will configure load balancer if service.type is LoadBalancer	{}
service.enabled	Enable non-headless service	true
service.externalTrafficPolicy	Some cloud providers allow you to specify the LoadBalancer externalTrafficPolicy. Kubernetes will use this to preserve the client source IP. This will configure load balancer if service.type is LoadBalancer	""
service.httpPortName	The name of the http port within the service	http
service.labelsHeadless	Labels to be added to headless service	{}
service.labels	Labels to be added to non-headless service	{}
service.loadBalancerIP	Some cloud providers allow you to specify the loadBalancer IP. If the loadBalancerIP field is not specified, the IP is dynamically assigned. If you specify a loadBalancerIP but your cloud provider does not support the feature, it is ignored.	""
service.loadBalancerSourceRanges	The IP ranges that are allowed to access	[]
service.nodePort	Custom nodePort port that can be set if you are using service.type: nodePort	""
service.transportPortName	The name of the transport port within the service	transport
service.publishNotReadyAddresses	Consider that all endpoints are considered "ready" even if the Pods themselves are not	false
service.type	Elasticsearch Service Types	ClusterIP
sysctlInitContainer	Allows you to disable the sysctlInitContainer if you are setting sysctl vm.max_map_count with another method	enabled: true
sysctlVmMaxMapCount	Sets the sysctl vm.max_map_count needed for Elasticsearch	262144
terminationGracePeriod	The terminationGracePeriod in seconds used when trying to stop the pod	120
tests.enabled	Enable creating test related resources when running helm template or helm test	true
tolerations	Configurable tolerations	[]
transportPort	The transport port that Kubernetes will use for the service. If you change this you will also need to set transport port configuration in extraEnvs	9300
updateStrategy	The updateStrategy for the StatefulSet. By default Kubernetes will wait for the cluster to be green after upgrading each pod. Setting this to OnDelete will allow you to manually delete each pod during upgrades	RollingUpdate
volumeClaimTemplate	Configuration for the volumeClaimTemplate for StatefulSets. You will want to adjust the storage (default 30Gi ) and the storageClassName if you are using a different storage class	see values.yaml

FAQ

How to deploy this chart on a specific K8S distribution?

This chart is designed to run on production scale Kubernetes clusters with multiple nodes, lots of memory and persistent storage. For that reason it can be a bit tricky to run them against local Kubernetes environments such as Minikube.

This chart is highly tested with GKE, but some K8S distribution also requires specific configurations.

We provide examples of configuration for the following K8S providers:

• Docker for Mac
• KIND
• Minikube
• MicroK8S
• OpenShift

How to deploy dedicated nodes types?

All the Elasticsearch pods deployed share the same configuration. If you need to deploy dedicated nodes types (for example dedicated master and data nodes), you can deploy multiple releases of this chart with different configurations while they share the same clusterName value.

For each Helm release, the nodes types can then be defined using roles value.

An example of Elasticsearch cluster using 2 different Helm releases for master, data and coordinating nodes can be found in examples/multi.

Coordinating nodes

Every node is implicitly a coordinating node. This means that a node that has an explicit empty list of roles will only act as a coordinating node.

When deploying coordinating-only node with Elasticsearch chart, it is required to define the empty list of roles in both roles value and node.roles settings:

roles: []

esConfig:
  elasticsearch.yml: |
    node.roles: []

More details in #1186 (comment)

Clustering and Node Discovery

This chart facilitates Elasticsearch node discovery and services by creating two Service definitions in Kubernetes, one with the name $clusterName-$nodeGroup and another named $clusterName-$nodeGroup-headless. Only Ready pods are a part of the $clusterName-$nodeGroup service, while all pods ( Ready or not) are a part of $clusterName-$nodeGroup-headless.

If your group of master nodes has the default nodeGroup: master then you can just add new groups of nodes with a different nodeGroup and they will automatically discover the correct master. If your master nodes have a different nodeGroup name then you will need to set masterService to $clusterName-$masterNodeGroup.

The chart value for masterService is used to populate discovery.zen.ping.unicast.hosts , which Elasticsearch nodes will use to contact master nodes and form a cluster. Therefore, to add a group of nodes to an existing cluster, setting masterService to the desired Service name of the related cluster is sufficient.

How to deploy clusters with security (authentication and TLS) enabled?

This Helm chart can generate a [Kubernetes Secret][] or use an existing one to setup Elastic credentials.

This Helm chart can use existing [Kubernetes Secret][] to setup Elastic certificates for example. These secrets should be created outside of this chart and accessed using environment variables and volumes.

This chart is setting TLS and creating a certificate by default, but you can also provide your own certs as a K8S secret. An example of configuration for providing existing certificates can be found in examples/security.

How to migrate from helm/charts stable chart?

If you currently have a cluster deployed with the helm/charts stable chart you can follow the migration guide.

How to install plugins?

The recommended way to install plugins into our Docker images is to create a custom Docker image.

The Dockerfile would look something like:

ARG elasticsearch_version
FROM docker.elastic.co/elasticsearch/elasticsearch:${elasticsearch_version}

RUN bin/elasticsearch-plugin install --batch repository-gcs

And then updating the image in values to point to your custom image.

There are a couple reasons we recommend this.

1. Tying the availability of Elasticsearch to the download service to install plugins is not a great idea or something that we recommend. Especially in Kubernetes where it is normal and expected for a container to be moved to another host at random times.
2. Mutating the state of a running Docker image (by installing plugins) goes against best practices of containers and immutable infrastructure.

How to use the keystore?

Basic example

Create the secret, the key name needs to be the keystore key path. In this example we will create a secret from a file and from a literal string.

kubectl create secret generic encryption-key --from-file=xpack.watcher.encryption_key=./watcher_encryption_key
kubectl create secret generic slack-hook --from-literal=xpack.notification.slack.account.monitoring.secure_url='https://hooks.slack.com/services/asdasdasd/asdasdas/asdasd'

To add these secrets to the keystore:

keystore:
  - secretName: encryption-key
  - secretName: slack-hook

Multiple keys

All keys in the secret will be added to the keystore. To create the previous example in one secret you could also do:

kubectl create secret generic keystore-secrets --from-file=xpack.watcher.encryption_key=./watcher_encryption_key --from-literal=xpack.notification.slack.account.monitoring.secure_url='https://hooks.slack.com/services/asdasdasd/asdasdas/asdasd'

keystore:
  - secretName: keystore-secrets

Custom paths and keys

If you are using these secrets for other applications (besides the Elasticsearch keystore) then it is also possible to specify the keystore path and which keys you want to add. Everything specified under each keystore item will be passed through to the volumeMounts section for mounting the secret. In this example we will only add the slack_hook key from a secret that also has other keys. Our secret looks like this:

kubectl create secret generic slack-secrets --from-literal=slack_channel='#general' --from-literal=slack_hook='https://hooks.slack.com/services/asdasdasd/asdasdas/asdasd'

We only want to add the slack_hook key to the keystore at path xpack.notification.slack.account.monitoring.secure_url:

keystore:
  - secretName: slack-secrets
    items:
    - key: slack_hook
      path: xpack.notification.slack.account.monitoring.secure_url

You can also take a look at the config example which is used as part of the automated testing pipeline.

How to enable snapshotting?

1. Install your snapshot plugin into a custom Docker image following the how to install plugins guide.
2. Add any required secrets or credentials into an Elasticsearch keystore following the how to use the keystore guide.
3. Configure the snapshot repository as you normally would.
4. To automate snapshots you can use Snapshot Lifecycle Management or a tool like curator.

How to configure templates post-deployment?

You can use postStart lifecycle hooks to run code triggered after a container is created.

Here is an example of postStart hook to configure templates:

lifecycle:
  postStart:
    exec:
      command:
        - bash
        - -c
        - |
          #!/bin/bash
          # Add a template to adjust number of shards/replicas
          TEMPLATE_NAME=my_template
          INDEX_PATTERN="logstash-*"
          SHARD_COUNT=8
          REPLICA_COUNT=1
          ES_URL=http://localhost:9200
          while [[ "$(curl -s -o /dev/null -w '%{http_code}\n' $ES_URL)" != "200" ]]; do sleep 1; done
          curl -XPUT "$ES_URL/_template/$TEMPLATE_NAME" -H 'Content-Type: application/json' -d'{"index_patterns":['\""$INDEX_PATTERN"\"'],"settings":{"number_of_shards":'$SHARD_COUNT',"number_of_replicas":'$REPLICA_COUNT'}}'

Contributing

Please check CONTRIBUTING.md before any contribution or for any questions about our development and testing process.