Allow injection of extra arguments into /etc/elasticsearch/elasticsearch.yml

[Paul Goins]

It may be desirable to allow for injection of arbitrary arguments into /etc/elasticsearch/elasticsearch.yml.

One use case is to work around pad.lv/1864794, as we could effectively put ES 7.0 into development mode by injecting the setting "discovery.type: single-node". (Without this or without proper bootstrap configuration, ES 7.0+ does not presently work with this charm.)

[Xav Paice (xavpaice)]

Is there a use case for this beyond adding ES 7 to the charm? Ideally, this kind of config option is used to get past the temporary need for additions to the charm, in this case support for a later release of the product, but the rule of thumb would be that if we need to use the config option, we should be raising a bug against the charm for it to do the right thing already.

[Launchpad Janitor (janitor)]

[Expired for Elasticsearch Charm because there has been no activity for 60 days.]