Is the RINGPOP_SEEDS environment variable still used?

I am referring to the section called Quickstart for production in the docker-compose readme.

The docker run example is as follows :

docker run -e CASSANDRA_SEEDS=10.x.x.x                  -- csv of Cassandra server ipaddrs
    -e KEYSPACE=<keyspace>                              -- Cassandra keyspace
    -e VISIBILITY_KEYSPACE=<visibility_keyspace>        -- Cassandra visibility keyspace
    -e SKIP_SCHEMA_SETUP=true                           -- do not setup Cassandra schema during startup
    -e RINGPOP_SEEDS=10.x.x.x,10.x.x.x  \               -- csv of ipaddrs for gossip bootstrap
    -e NUM_HISTORY_SHARDS=1024  \                       -- Number of history shards
    -e SERVICES=history,matching \                      -- Spin-up only the provided services
    -e LOG_LEVEL=debug,info \                           -- Logging level
    -e DYNAMIC_CONFIG_FILE_PATH=config/foo.yaml         -- Dynamic config file to be watched

Is RINGPOP_SEEDS needed, or does the discovery happen via the database as mentioned in What is the equivalent of cadence:bootstrapHosts in temporal - #3 by shawn

If RINGPOP_SEEDS is still needed in a deployment for discovery, is it possible to get some guidance on the best practices. Is it expected that at-least one or more servers be maintained on a certain static IP. Or any ideas on how to manage passing on some seed IP’s if all the cluster members can fail and restart with some different IPs?

No, this env is not needed, we just forget to remove it from files. Every node automatically register itself in database and new nodes get seed IPs from there. You don’t need to setup anything there.