Elasticsearch Version 5.1.2 Fails to Start because of the xpack.ml.enabled setting

[bowlesns]

Elasticsearch version
5.1.2

Role version
Master

JVM version
1.8.0_151

OS version
Darwin Kernel Version 15.6.0

Description of the problem including expected versus actual behavior
When attempting to start Elasticsearch from the Ansible playbook, startup fails because of the below error. It appears the elasticsearch.yml.j2 tries to set xpack.ml.enabled to false, but because the machine learning plugin wasn't present in earlier versions, the startup fails because of the unknown setting. Removing the following entry from /templates/elasticsearch.yml.j2 allows for successful startup.

{% if not "ml" in es_xpack_features %}
xpack.ml.enabled: false
{% endif %}

I'm guessing there needs to be a way for that setting to be set conditionally upon if the es_version is 5.4 or greater and that would allow the playbook to successfully execute and start Elasticsearch with xpack on earlier versions.

Playbook (removed IP addresses)

• hosts: es-master
  user: ubuntu
  become: true
  roles:
  • role: elastic.elasticsearch
    es_instance_name: "{{inventory_hostname}}"
    es_heap_size: "25g"
    es_version: 5.1.2
    es_enable_xpack: true
    es_xpack_license: "{{ lookup('file', 'files/' + 'esXpackLicense.json') }}"
    es_api_basic_auth_username: es_admin
    es_api_basic_auth_password: password123
    es_api_host: xx.x.x.xxx
    es_api_port: 9200
    es_config:
    cluster.name: "elasticsearch"
    discovery.zen.ping.unicast.hosts:
    - xx.x.x.xxx:9300
    http.port: 9200
    transport.tcp.port: 9300
    node.data: false
    node.master: true
    bootstrap.memory_lock: false
    network.host: 0.0.0.0
    es_xpack_features:
    • security
    • alerting
      es_message_auth_file: system_key
      es_users:
      file:
      es_admin:
      password: password123
      roles:
      - admin
      es_roles:
      file:
      admin:
      cluster:
      - all
      indices:
      - names: '*'
      privileges:
      - all

Provide logs from Ansible:
Playbook times out on the
TASK [elastic.elasticsearch : Wait for elasticsearch to startup] step.

ES Log
[2017-12-19T00:25:00,138][ERROR][o.e.b.Bootstrap ] Exception
java.lang.IllegalArgumentException: unknown setting [xpack.ml.enabled] did you mean [xpack.graph.enabled]?
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:278) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:246) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.common.settings.SettingsModule.(SettingsModule.java:138) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.node.Node.(Node.java:325) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.node.Node.(Node.java:229) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Bootstrap$6.(Bootstrap.java:214) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:214) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:306) [elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:121) [elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:112) [elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.cli.SettingCommand.execute(SettingCommand.java:54) [elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:122) [elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.cli.Command.main(Command.java:88) [elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:89) [elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:82) [elasticsearch-5.1.2.jar:5.1.2]

[2017-12-19T00:25:00,142][WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler] [x.x.x.xxxx-Node-x.x.x.xxxx] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.IllegalArgumentException: unknown setting [xpack.ml.enabled] did you mean [xpack.graph.enabled]?
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:125) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:112) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.cli.SettingCommand.execute(SettingCommand.java:54) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:122) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.cli.Command.main(Command.java:88) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:89) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:82) ~[elasticsearch-5.1.2.jar:5.1.2]
Caused by: java.lang.IllegalArgumentException: unknown setting [xpack.ml.enabled] did you mean [xpack.graph.enabled]?
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:278) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:246) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.common.settings.SettingsModule.(SettingsModule.java:138) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.node.Node.(Node.java:325) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.node.Node.(Node.java:229) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Bootstrap$6.(Bootstrap.java:214) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:214) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:306) ~[elasticsearch-5.1.2.jar:5.1.2]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:121) ~[elasticsearch-5.1.2.jar:5.1.2]

[pemontto]

You'll want to use version_compare, something like es_version | version_compare('5.4', '>')

[jmlrt]

I think this should be fixed by #560

[jmlrt]

I'm closing the issue, don't hesitate to reopen it if you have any question.