# Neo4j

[Neo4j](https://neo4j.com/) 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;

```bash
$ helm install stable/neo4j
```

## Introduction

This chart bootstraps a [Neo4j](https://github.com/neo4j/docker-neo4j)
deployment on a [Kubernetes](http://kubernetes.io) cluster using the
[Helm](https://helm.sh) package manager.

## 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.

## Installing the Chart

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

```bash
$ helm install --name neo4j-helm 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](#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:

```bash
$ 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`                                          |
| `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 the APOC library                                     | `{}`                                            |
| `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.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 pod. Example use case is a script that installs the APOC library                                  | `{}`                                            |
| `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](https://github.com/neo4j/docker-neo4j).

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

```bash
$ helm install --name neo4j-helm --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,

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

> **Tip**: You can use the default [values.yaml](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.
