Skip to content
This repository has been archived by the owner on May 28, 2024. It is now read-only.

Latest commit

 

History

History
475 lines (382 loc) · 42 KB

README.md

File metadata and controls

475 lines (382 loc) · 42 KB
Raw

Elasticsearch Helm Chart

This functionality is in beta and is subject to change. The design and code is less mature than official GA features and is being provided as-is with no warranties. Beta features are not subject to the support SLA of official GA features.

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

Requirements

  • Helm >=2.8.0 and <3.0.0 (see parent README for more details)
  • Kubernetes >=1.8
  • 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

Installing

Using Helm repository

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

  • Install it: helm install --name elasticsearch elastic/elasticsearch

Using master branch

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

  • Install it: helm install --name elasticsearch ./helm-charts/elasticsearch

Upgrading

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

Compatibility

This chart is tested with the latest supported versions. The currently tested versions are:

6.x 7.x
6.8.8 7.6.2

Examples of installing older major versions can be found in the examples directory.

While only the latest releases are tested, it is possible to easily install old or new releases by overriding the imageTag. To install version 7.6.2 of Elasticsearch it would look like this:

helm install --name elasticsearch elastic/elasticsearch --set imageTag=7.6.2

Usage notes

  • This repo includes a number of examples configurations which 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
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 should configure the jvm heap size -Xmx1g -Xms1g
esMajorVersion 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 ""
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 7.6.2
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 ""
masterTerminationFix A workaround needed for Elasticsearch < 7.2 to prevent master status being lost during restarts #63 false
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
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" 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 hash map with the specific roles for the nodeGroup see values.yaml
schedulerName Name of the alternate scheduler ""
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.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.type Elasticsearch Service Types ClusterIP
sidecarResources Allows you to set the resources for the sidecar containers in the StatefulSet {}
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
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

Deprecated

Parameter Description Default
fsGroup The Group ID (GID) for securityContext so that the Elasticsearch user can read from the persistent volume ""

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:

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 and data nodes can be found in examples/multi.

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 use existing Kubernetes secrets to setup credentials or certificates for examples. These secrets should be created outside of this chart and accessed using environment variables and volumes.

An example of Elasticsearch cluster using security 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 OSS version of Elasticsearch

Deploying OSS version of Elasticsearch can be done by setting image value to Elasticsearch OSS Docker image

An example of Elasticsearch cluster using OSS version can be found in examples/oss.

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 a tool like curator. In the future there are plans to have Elasticsearch manage automated snapshots with Snapshot Lifecycle Management.

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.