I am configuring an ES cluster in a Kubernetes cluster, so I am using docker image for ES 5.2.0 from dockerhub. I am passing configuration values via environment variables (using values I have seen in serveral samples I found), however when an instance of ES comes online it looks to be in a default configuration.
I can log into the container and confirm that env variables are set, however looks they are not picked up.
For example I set CLUSTER_NAME to "TEST", and can confirm that container gets the value
/usr/share/elasticsearch# echo $CLUSTER_NAME
When I navigate to ES I see that "cluster_name" : "elasticsearch"
I have tried lowercase name for env variables, with same results.
What is the proper way to pass params to docker image, and make sure that ES instance picks them up?