Can't lock memory on ES cluster

Elastic Stack Elasticsearch
5

I tried that option as well. Verified that ulimit and memory_lock are set via docker inspect <container_name> and docker exec <container_name> env. Both were set as expected.

But when I verify through curl localhost:9200/_nodes?filter_path=**.mlockall. I get false for all. No errors in the log as well. Looks like the environment variable and the ulimit option is ignored.

{
  "nodes": {
    "node1": {
      "process": {
        "mlockall": false
      }
    },
    "node2": {
      "process": {
        "mlockall": false
      }
    },
    "node3": {
      "process": {
        "mlockall": false
      }
    },
    "node4": {
      "process": {
        "mlockall": false
      }
    },
    "node5": {
      "process": {
        "mlockall": false
      }
    }
  }
}