Install
https://www.elastic.co/guide/en/elasticsearch/client/curator/5.x/apt-repository.html

wget -qO - https://packages.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -
echo "deb [arch=amd64] https://packages.elastic.co/curator/5/debian stable main" > /etc/apt/sources.list.d/curator.list
sudo apt-get update && sudo apt-get install elasticsearch-curator

# sudo apt install -y elasticsearch-curator
# pip install elasticsearch-curator

Show usage

curl elasticsearch.example.com:9200/_cat/indices

curator.yml

---
client:
  hosts:
    - elasticsearch.example.com
  port: 9200
  url_prefix:
  use_ssl: False
  certificate:
  client_cert:
  client_key:
  ssl_no_validate: False
  http_auth:
  timeout: 30
  master_only: False

logging:
  loglevel: INFO
  logfile:
  logformat: default
  blacklist: ['elasticsearch', 'urllib3']

delete_indices.yml

---
actions:
  1:
    action: delete_indices
    description: >-
      Delete indices older than 14 days
    options:
      ignore_empty_list: True
      timeout_override:
      continue_if_exception: False
      disable_action: False
    filters:
#    - filtertype: pattern
#      kind: prefix
#      value: logstash-
#      #value: flog-
#      exclude:
#    - filtertype: pattern
#      kind: prefix
#      value: flog-
#      exclude:
    - filtertype: age
      source: name
      direction: older
      timestring: '%Y.%m.%d'
      unit: days
      unit_count: 7
      exclude:

Delete old data

curator --config ./curator.yml ./delete_indices.yml #--dry-run

Links
http://www.madhur.co.in/blog/2017/04/09/usingcuratordeleteelasticindex.html
https://cezarypiatek.github.io/post/scheduled-elasticsearch-cleanup/