gem "alterity"

Alterity.configure do |config|

  # You can fully customize the command that's will be executed, for example:
  config.command = -> (altered_table, alter_argument) {
    <<~SHELL.squish
    pt-online-schema-change
      -h #{config.host}
      -P #{config.port}
      -u #{config.username}
      --password=#{config.password}
      --alter-foreign-keys-method=auto
      --nocheck-replication-filters
      --critical-load Threads_running=1000
      --max-load Threads_running=200
      --set-vars lock_wait_timeout=1
      --recursion-method 'dsn=D=#{config.replicas_dsns_database},t=#{config.replicas_dsns_table}'
      --execute
      --no-check-alter
      D=#{config.database},t=#{altered_table}
      --alter #{alter_argument}
    SHELL
  }
  # Check out lib/alterity/default_configuration.rb to see the default command used.

  # This option, deactivated by default, will set up a database & table
  # and fill them with the listed DSNs before running migrations.
  # This is useful for PT-OSC (parameter `--recursion-method`) to monitor
  # the replica lag while copying rows.
  # This table will be truncated and re-filled every time you run migrations.
  # See the method `prepare_replicas_dsns_table` in lib/alterity/alterity.rb for details.
  config.replicas(
    database: "percona",
    table: "replicas_dsns",
    dsns: [
      "h=#{ENV["DB_REPLICA1_HOST"]}",
      "h=#{ENV["DB_REPLICA2_HOST"]}",
    ]
  )

  # You can set callbacks that run before, during and after a PT-OSC run.
  # Useful if you need to have details of the migration logged somewhere specific.
  # Examples:
  config.before_command = ->(command) { Slack.send_message("#migrations", "Will execute: #{command}") }
  config.on_command_output = ->(line) { Slack.send_message("#migrations", line) }
  config.after_command = ->(exit_status) { Slack.send_message("#migrations", "Command exited with status: #{exit_status}") }
end

Alterity.disable do
  add_column :users, :full_name, :string
end