本番環境のデータを別環境に差分コピーするRuby製ツールを作りました ref: https://qiita.com/nishio-dens/items/182d752da57e6b46c023

file0.txt

gem install gamma

file1.sql

CREATE TABLE `ar_internal_metadata` (
  `key` varchar(255) NOT NULL,
  `value` varchar(255) DEFAULT NULL,
  `created_at` datetime NOT NULL,
  `updated_at` datetime NOT NULL,
  PRIMARY KEY (`key`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE TABLE `products` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `image_path` varchar(512) DEFAULT NULL,
  `created_at` datetime DEFAULT NULL,
  `updated_at` datetime DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE TABLE `users` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `email` varchar(255) DEFAULT NULL,
  `encrypted_password` varchar(255) DEFAULT NULL,
  `created_at` datetime DEFAULT NULL,
  `updated_at` datetime DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

file10.rb

# hooks/mask_email.rb

# hooks の column 指定をすると、対象行の column名 と value がhookスクリプトに渡されます
# apply は dryrunのときには false となります

class MaskEmail
  def execute(apply, column, value)
    result = value.split("@")[0]
    result = "#{result}@example.com"

    unless apply
      puts "[DRYRUN] #{column} #{value}"
    end

    result
  end
end

file11.txt

gamma dryrun --settings settings.yml --data data.yml

file12.rb

I, [2018-03-11T18:51:35.611121 #76155]  INFO -- : [replace] Sync Start products
[DRYRUN] Copy Image: {"id"=>686, "name"=>"production_product_685", "image_path"=>"/test/image/685.png", "created_at"=>2018-03-11 06:13:27 +0900, "updated_at"=>2018-03-11 02:13:27 +0900}
I, [2018-03-11T18:51:35.726459 #76155]  INFO -- : DRYRUN: UPDATE `products` SET `id` = "686",`name` = "production_product_685",`image_path` = "/test/image/685.png",`created_at` = "2018-03-11 06:13:27",`updated_at` = "2018-03-11 02:13:27" WHERE id = 686

I, [2018-03-11T18:51:36.618468 #76155]  INFO -- : [replace] Sync Start users
[DRYRUN] email test_email_0@example.com
I, [2018-03-11T18:51:36.739384 #76155]  INFO -- : DRYRUN: UPDATE `users` SET `id` = "1",`email` = "test_email_0@example.com",`encrypted_password` = "cfcd208495d565ef66e7dff9f98764da",`created_at` = "2018-03-11 06:13:23",`updated_at` = "2018-03-11 13:13:23" WHERE id = 1

[DRYRUN] email test_email_1@example.com
I, [2018-03-11T18:51:36.739654 #76155]  INFO -- : DRYRUN: UPDATE `users` SET `id` = "2",`email` = "test_email_1@example.com",`encrypted_password` = "c4ca4238a0b923820dcc509a6f75849b",`created_at` = "2018-03-11 06:13:23",`updated_at` = "2018-03-11 13:13:23" WHERE id = 2

file13.txt

gamma apply --settings settings.yml --data data.yml

file14.txt

I, [2018-03-11T18:52:32.250442 #76616]  INFO -- : [replace] Sync Start products
Copy Image. path: /test/image/685.png
I, [2018-03-11T18:52:33.268832 #76616]  INFO -- : [replace] Sync Start users

file2.yml

# settings.yml

in_database_config:
  adapter: mysql2
  encoding: utf8
  database: gamma_production
  pool: 5
  host: localhost
  username: root
  password:
out_database_config:
  adapter: mysql2
  encoding: utf8
  database: gamma_development
  pool: 5
  host: localhost
  username: root
  password:

file3.yml

# data.yml

- data:
    table:
      - "*"
    table_without:
      - "ar_internal_metadata"
    mode: "replace"
    delta_column: "updated_at"

file4.txt

gamma dryrun --settings settings.yml --data data.yml

file5.rb

I, [2018-03-11T19:02:54.482910 #81194]  INFO -- : [replace] Sync Start products
I, [2018-03-11T19:02:54.612671 #81194]  INFO -- : DRYRUN: INSERT INTO products(`id`,`name`,`image_path`,`created_at`,`updated_at`) VALUES ("9","production_product_8","/test/image/8.png","2018-03-11 06:13:26","2018-03-11 06:13:26")

I, [2018-03-11T19:02:55.518998 #81194]  INFO -- : [replace] Sync Start users
I, [2018-03-11T19:02:55.633015 #81194]  INFO -- : DRYRUN: UPDATE `users` SET `id` = "12",`email` = "test_email_11@example.com",`encrypted_password` = "6512bd43d9caa6e02c990b0a82652dca",`created_at` = "2018-03-11 06:13:23",`updated_at` = "2018-03-11 06:13:23" WHERE id = 12

I, [2018-03-11T19:02:55.633129 #81194]  INFO -- : DRYRUN: INSERT INTO users(`id`,`email`,`encrypted_password`,`created_at`,`updated_at`) VALUES ("14","test_email_13@example.com","c51ce410c124a10e0db5e4b97fc2af39","2018-03-11 06:13:23","2018-03-11 06:13:23")

file6.txt

gamma apply --settings settings.yml --data data.yml

file7.rb

I, [2018-03-11T18:42:44.713544 #72090]  INFO -- : [replace] Sync Start products
I, [2018-03-11T18:42:45.722601 #72090]  INFO -- : [replace] Sync Start users

file8.yml

- data:
    table:
      - "products"
    mode: "replace"
    delta_column: "updated_at"
    hooks:
      - row:
          scripts:
            - "hooks/copy_image.rb"
- data:
    table:
      - "users"
    mode: "replace"
    delta_column: "updated_at"
    hooks:
      - column:
          name:
            - "email"
          scripts:
            - "hooks/mask_email.rb"

file9.rb

# hooks/copy_image.rb

# hooks の row指定をすると、特定行全てが含まれた値がhookスクリプトに渡されます
# apply は dryrunのときには false となります
# record には DBのレコードが入っています

class CopyImage
  def execute(apply, record)
    if apply
      # ここに画像コピーする処理を記載する
      puts "Copy Image. path: #{record["image_path"]}"
    else
      puts "[DRYRUN] Copy Image: #{record}"
    end

    record
  end
end