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Logstash Helm Chart

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

Warning: 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. Alpha features are not subject to the support SLA of official GA features (see supported configurations for more details).

Warning: This branch is used for development, please use 7.8.0 release for released version.

Requirements

  • Helm >=2.8.0 and <3.0.0
  • Kubernetes >=1.8

See supported configurations for more details.

Installing

Install released version using Helm repository

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

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

Install development version using master branch

  • Clone the git repo: git clone [email protected]:elastic/helm-charts.git

  • Install it: helm install --name logstash ./helm-charts/logstash --set imageTag=8.0.0-SNAPSHOT

Upgrading

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

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 logstashJavaOpts and to set the CPU/Memory resources to something suitable for your cluster.
  • We have designed this chart to be very un-opinionated about how to configure Logstash. 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.
  • logstash.yml configuration files can be set either by a ConfigMap using logstashConfig in values.yml or by environment variables using extraEnvs in values.yml , however Logstash Docker image can't mix both methods as defining settings with environment variables causes logstash.yml to be modified in place while using ConfigMap bind-mount the same file (more details in this note).
  • When overriding logstash.yml, http.host: 0.0.0.0 should always be included to make default probes work. If restricting HTTP API to 127.0.0.1 is required by using http.host: 127.0.0.1, default probes should be disabled or overrided (see values.yaml for the good syntax).

Configuration

Parameter Description Default
antiAffinityTopologyKey The anti-affinity topology key]. By default this will prevent multiple Logstash 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
envFrom Templatable string to be passed to the environment from variables which will be appended to the envFrom: definition for the container []
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 ""
extraPorts An array of extra ports to open on the pod []
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 full name of the resources. If not set the name will default to " .Release.Name - .Values.nameOverride or .Chart.Name " ""
httpPort The http port that Kubernetes will use for the healthchecks and the service 9600
imagePullPolicy The Kubernetes imagePullPolicy value IfNotPresent
imagePullSecrets Configuration for imagePullSecrets so that you can use a private registry for your image []
imageTag The Logstash Docker image tag 8.0.0-SNAPSHOT
image The Logstash Docker image docker.elastic.co/logstash/logstash
labels Configurable labels applied to all Logstash pods {}
lifecycle Allows you to add lifecycle configuration. See values.yaml for an example of the formatting {}
livenessProbe Configuration fields for the liveness probe see values.yaml
logstashConfig Allows you to add any config files in /usr/share/logstash/config/ such as logstash.yml and log4j2.properties See values.yaml for an example of the formatting {}
logstashJavaOpts Java options for Logstash. This is where you should configure the JVM heap size -Xmx1g -Xms1g
logstashPipeline Allows you to add any pipeline files in /usr/share/logstash/pipeline/ {}
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
nameOverride Overrides the chart name for resources. If not set the name will default to .Chart.Name ""
nodeAffinity Value for the node affinity settings {}
nodeSelector Configurable nodeSelector so that you can target specific nodes for your Logstash cluster {}
persistence Enables a persistent volume for Logstash data see values.yaml
podAnnotations Configurable annotations applied to all Logstash 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 ""
rbac Configuration for creating a role, role binding and service account as part of this Helm chart with create: true Also can be used to reference an external service account 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) 1
resources Allows you to set the resources for the StatefulSet 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 Configurable service to expose the Logstash service. see values.yaml
terminationGracePeriod The terminationGracePeriod in seconds used when trying to stop the pod 120
tolerations Configurable tolerations []
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 install OSS version of Logstash?

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

An example of Logstash deployment 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 logstash_version
FROM docker.elastic.co/logstash/logstash:${logstash_version}
RUN bin/logstash-plugin install logstash-output-kafka

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 Logstash 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.

Contributing

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