$ go build -o elastically ./cmd
$ ./elastically -h

Usage: elastically [--url URL] [--sniff] [--loglevel LOGLEVEL] <command> [<args>]

Options:
  --url URL, -u URL
  --sniff, -s            Sniff nodes, then connect to them
  --loglevel LOGLEVEL [default: info]
  --help, -h             display this help and exit

Commands:
  index

Usage: elastically index <command> [<args>]

Options:
  --help, -h             display this help and exit

Commands:
  list
  delete

$ elastically index list   
.opensearch_dashboards_1
fluentd
logstash-2021.04.18
(...)

$ elastically index delete fluentd
fluentd delete successfully!