/neo4j-helm

Helm Charts for running Neo4j on Kubernetes

Primary LanguageSmarty

Neo4j

Neo4j is a highly scalable native graph database that leverages data relationships as first-class entities, helping enterprises build intelligent applications to meet today’s evolving data challenges.

TL;DR;

$ helm install stable/neo4j

Introduction

This chart bootstraps a Neo4j deployment on a Kubernetes cluster using the Helm package manager.

This package is fairly similar to the Neo4j-maintained GKE Marketplace entry, which is also built on helm. This package tries to avoid Kubernetes distribution-specific features to be general, while the other is tailored specifically to GKE.

Prerequisites

  • Kubernetes 1.6+ with Beta APIs enabled
  • PV provisioner support in the underlying infrastructure
  • Requires the following variables You must add acceptLicenseAgreement in the values.yaml file and set it to yes or include --set acceptLicenseAgreement=yes in the command line of helm install to accept the license.
  • This chart requires that you have a license for Neo4j Enterprise Edition. Trial licenses can be obtained here

Installing the Chart

To install the chart with the release name neo4j-helm:

$ helm install --name my-neo4j stable/neo4j --set acceptLicenseAgreement=yes --set neo4jPassword=mySecretPassword

You must explicitly accept the neo4j license agreement for the installation to be successful.

The command deploys Neo4j on the Kubernetes cluster in the default configuration but with the password set to mySecretPassword. The 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 neo4j-helm deployment:

$ helm delete neo4j-helm --purge

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 Neo4j chart and their default values.

Parameter Description Default
image Neo4j image neo4j
imageTag Neo4j version {VERSION}
imagePullPolicy Image pull policy IfNotPresent
podDisruptionBudget Pod disruption budget {}
authEnabled Is login/password required? true
useAPOC Should the APOC plugins be automatically installed in the database? true
defaultDatabase The name of the default database to configure in Neo4j (dbms.default_database) neo4j
neo4jPassword Password to log in the Neo4J database if password is required (random string of 10 characters)
core.configMap Configmap providing configuration for core cluster members. If not specified, defaults that come with the chart will be used. $NAME-neo4j-core-config
core.numberOfServers Number of machines in CORE mode 3
core.sideCarContainers Sidecar containers to add to the core pod. Example use case is a sidecar which identifies and labels the leader when using the http API {}
core.initContainers Init containers to add to the core pod. Example use case is a script that installs custom plugins/extensions {}
core.persistentVolume.enabled Whether or not persistence is enabled true
core.persistentVolume.storageClass Storage class of backing PVC standard (uses beta storage class annotation)
core.persistentVolume.size Size of data volume 10Gi
core.persistentVolume.mountPath Persistent Volume mount root path /data
core.persistentVolume.subPath Subdirectory of the volume to mount nil
core.persistentVolume.annotations Persistent Volume Claim annotations {}
readReplica.configMap Configmap providing configuration for RR cluster members. If not specified, defaults that come with the chart will be used. $NAME-neo4j-replica-config
readReplica.numberOfServers Number of machines in READ_REPLICA mode 0
readReplica.autoscaling.enabled Enable horizontal pod autoscaler false
readReplica.autoscaling.targetAverageUtilization Target CPU utilization 70
readReplica.autoscaling.minReplicas Min replicas for autoscaling 1
readReplica.autoscaling.maxReplicas Max replicas for autoscaling 3
readReplica.initContainers Init containers to add to the replica pods. Example use case is a script that installs custom plugins/extensions {}
resources Resources required (e.g. CPU, memory) {}
clusterDomain Cluster domain cluster.local

The above parameters map to the env variables defined in the Neo4j docker image.

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

$ helm install my-neo4j --set core.numberOfServers=5,readReplica.numberOfServers=3 stable/neo4j

The above command creates a cluster containing 5 core servers and 3 read replicas.

Alternatively, a YAML file that specifies the values for the parameters can be provided while installing the chart. For example,

$ helm install --name neo4j-helm -f values.yaml stable/neo4j

Tip: You can use the default values.yaml

Once you have all 3 pods in running, you can run the "test.sh" script in this directory, which will verify the role attached to each pod and also test recovery of a failed/deleted pod. This script requires that the $RELEASE_NAME environment variable be set, in order to access the pods, if you have specified a custom namespace or replicas value when installing you can set those via RELEASE_NAMESPACE and CORE_REPLICAS environment variables for this script.

Using Custom Configuration

The pods in two groups (Cores and read-replicas) are configured with regular ConfigMaps, which turn into environment variables. Those environment variables configure the Neo4j pods according to Neo4j environment variable configuration.

If you want to do custom configuration, just do so like this:

--set core.configMap=myConfigMapName --set readReplica.configMap=myReplicaConfigMap

And that will be used instead. Note: configuration of some networking specific settings is still done at container start time, and this very small set of variables may still be overridden by the helm chart, in particular advertised addresses & hostnames for the containers.

Additional Documentation for Running Neo4j in Kubernetes

Upgrading

Version numbers here refer to helm chart versions, not Neo4j product versions.

To 3.0.0

Backwards compatibility is not guaranteed unless you modify the labels used on the chart's deployments. The 2.0.0 chart was based around Neo4j's 3.5.x product series. The 3.0 chart is based around Neo4j's 4.0.x product series, and there are substantial differences between these two. Careful upgrade planning is advised before attempting to upgrade an existing chart. Consult the upgrade guide and expect that additional configuration of this chart will be necessary.

To 2.0.0

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 2.0.0. The following example assumes that the release name is neo4j:

$ kubectl delete statefulset.apps neo4j-neo4j-core --cascade=false
$ kubectl delete deployments.apps neo4j-neo4j-replica --cascade=false