message: Adding Environment Variables for Elasticsearch
diff: * 6 [Dockerfile](https://github.com/uselagoon/lagoon-images/blob/main/images/elasticsearch/6.Dockerfile) - `uselagoon/elasticsearch-6`
  * 7 [Dockerfile](https://github.com/uselagoon/lagoon-images/blob/main/images/elasticsearch/7.Dockerfile) - `uselagoon/elasticsearch-7`
  +
  +## Environment Variables
  +
  +| Environment Variable | Default | Description |
  +| :------------------- | :---------------- | :------------------------------------------------------------------------------------------------------------------------------- |
  +| `ES_JAVA_OPTS` | -Xms400m -Xmx400m | Sets the memory usage of the Elasticsearch container. Both values need be the same value or Elasticsearch will not start cleanly |
  +
  +
  ## Known issues
  On Linux-based systems, the start of the Elasticsearch container may fail due to a low `vm.max_map_count` setting.
  