[elasticsearch] Cannot run a single node cluster

Chart version:

7.4.0

Kubernetes version:

1.14.0

Kubernetes provider:

on-premise

Helm Version:

2.X

Describe the bug:

As a developper, I want to run a simple elasticsearch cluster, with a single node.

Steps to reproduce:

As indicated here https://www.elastic.co/guide/en/elasticsearch/reference/current/bootstrap-checks.html, values.yml:

esConfig:
  elasticsearch.yml: |
    discovery:
      type: single-node
      seed_hosts: ""

Expected behavior:

A single pod should run.

Provide logs and/or server output (if relevant):

This chart is hardcoding the setting cluster.initial_master_nodes which throw the exception

stacktrace": ["org.elasticsearch.bootstrap.StartupException: java.lang.IllegalArgumentException: setting [cluster.initial_master_nodes] is not allowed when [discovery.type] is set to [single-node]"

[Crazybus]

Another thing worth checking. Can you show the output of kubectl get pv. If you previously had a 3 node cluster and didn’t delete the volumes after them being used the one node cluster will start up expecting to find 2 more nodes.

[evtimmy]

@gilperme @DaimyGovaert for me, setting the value to null did the trick:

  extraEnvs:
  - name: discovery.type
    value: single-node
  - name: cluster.initial_master_nodes
    value: null