How to import data from PostgreSQL to elastic search?

1. Export data to json : https://hashrocket.com/blog/posts/create-quick-json-data-dumps-from-postgresql
2. Import data from json file : curl -XPUT localhost:9200/_bulk --data-binary @shakespeare.json

You can use logstash for this where a sample config file to ship data from POSTGRES to elasticsearch would like below. You can follow this link for a detailed tutorial

input {
  jdbc {
  jdbc_connection_string => "jdbc:postgresql://:5432/"
  jdbc_user => "<my-username>"
  jdbc_password => "<my-password>"
  jdbc_driver_library => "///postgresql-42.1.4.jar"
  jdbc_driver_class => "org.postgresql.Driver"
  statement => "SELECT * from contact"
  }
}
output {
  elasticsearch {
  index => "contact"
  hosts => ["localhost:9200"]
  }
}