Using Kubernetes service discovery for ES_SEEDS

[mhmtszr]

What are you really trying to do?

Deploying highly available Temporal cluster.

Describe the bug

We are using Kubernetes for our Temporal clusters. We don't want to give only one ip for ES_SEEDS because it can be changed thus we want to give our Kubernetes service definition. But our services contain port as well. I can give empty ES_PORT but still there is ":" character between seeds and port.

We also tried to give all IPs of the cluster seperated by comma(which is we didn't want to), but in this case Temporal server got some errors from Elasticsearch, It tried to send a request like this POST 10.10.10.1,10.10.10.2,10.10.10.3/mapping.

We can make ES_PORT totally optional in both auto-setup and Temporal server. What do you think about this? Do you have any different suggestions to us?

Or we can set ES_SERVER directly that it can overwrite.