Support for ElasticSearch in charts

Problem statement

Currently, it is not possible to use ElasticSearch to improve the searching capabilities of GitLab using the charts.

Gitlab::Elastic::Indexer::Error: log writing failed. failed to resolve path '/var/opt/gitlab/repo/@hashed/58/08/580811fa95269f3ecd4f22d176e079d36093573680b6ef66fa341e687a15b5da.git': No such file or di...

Solution

Recently, our ElasticSearch functionality has removed the need for shared storage, allowing us to support this with CNG.

We should add that support. We should just need to add the new indexer binary to the images.

Documentation

We should ensure the documentation for setting up ElasticSearch has been added to the documentation. Examples would be great, as it will have to be an external ES cluster.