### Background Our elasticsearch configuration is currently managed by a set of custom scripts [in the runbooks repo](https://gitlab.com/gitlab-com/runbooks/-/tree/master/elastic). ### Problem This configuration is messy and error-prone: - Requires coordinating changes across different files, sometimes different languages (as some of the config is in jsonnet). - This makes it difficult to introduce new indices. - There is no drift detection. ### Proposal Migrate from custom scripts to terraform. There is a newly released [official terraform provider for elastic](https://registry.terraform.io/providers/elastic/elasticstack/latest/docs). This would allow us to specify: - cluster configuration - index templates - ILM policies - users In a way that is is more accessible and ensures we detect config drift. ### Previous discussions - https://gitlab.com/groups/gitlab-com/gl-infra/-/epics/333 - https://gitlab.com/gitlab-com/gl-infra/infrastructure/-/issues/10488