How do I disable X-Pack security on the elasticsearch 5.2.2 docker image?

It worked for me.

I just ran:

docker run -d -p 9200:9200 --name elasticsearch -e "http.host=0.0.0.0" -e "transport.host=127.0.0.1" -e "xpack.security.enabled=false" docker.elastic.co/elasticsearch/elasticsearch:5.2.2
curl 127.0.0.1:9200

And got:

{
  "name" : "NA9O7g6",
  "cluster_name" : "docker-cluster",
  "cluster_uuid" : "4c9iUQZSTN2XlRb_7wnY4g",
  "version" : {
    "number" : "5.2.2",
    "build_hash" : "f9d9b74",
    "build_date" : "2017-02-24T17:26:45.835Z",
    "build_snapshot" : false,
    "lucene_version" : "6.4.1"
  },
  "tagline" : "You Know, for Search"
}