Active record via SSH Tunnel https://coderwall.com/p/twi-nw/using-a-database-through-an-ssh-tunnel-in-a-rails-environment

Active record via SSH Tunnel.txt

require 'net/ssh/gateway'
require 'active_record'

# there is no password here as the local user `user` has an SSH key stored on the remote server
gateway = Net::SSH::Gateway.new('domain.tld', 'user')
port = gateway.open('127.0.0.1', 3306, 3307)

ActiveRecord::Base.establish_connection(
  adapter: 'mysql2',
  host: '127.0.0.1',
  username: 'dbuser',
  password: 'dbpassword',
  database: 'dbname',
  port: port
)