EvilSeed
EvilSeed is a tool for creating partial anonymized dump of your database based on your app models.
Motivation
Using production-like data in your staging environment could be very useful, especially for debugging intricate production bugs.
The easiest way to achieve this is to use production database backups. But that's not an option for rather large applications for two reasons:
-
production dump can be extremely large, and it just can't be dumped and restored in a reasonable time
-
you should care about sensitive data (anonymization).
EvilSeed aims to solve these problems.
Installation
Add this line to your application's Gemfile:
gem 'evil-seed', require: false
And then execute:
$ bundle
Or install it yourself as:
$ gem install evil-seed
Usage
Configuration
require 'evil_seed'
EvilSeed.configure do |config|
# First, you should specify +root models+ and their +constraints+ to limit the number of dumped records:
# This is like Forum.where(featured: true).all
config.root('Forum', featured: true) do |root|
# It's possible to remove some associations from dumping with pattern of association path to exclude
#
# Association path is a dot-delimited string of association chain starting from model itself:
# example: "forum.users.questions"
root.exclude(/\btracking_pixels\b/, 'forum.popular_questions')
# It's possible to limit the number of included into dump has_many and has_one records for every association
# Note that belongs_to records for all not excluded associations are always dumped to keep referential integrity.
root.limit_associations_size(100)
# Or for certain association only
root.limit_associations_size(10, 'forum.questions')
end
# Everything you can pass to +where+ method will work as constraints:
config.root('User', 'created_at > ?', Time.current.beginning_of_day - 1.day)
# For some system-wide models you may omit constraints to dump all records
config.root("Role") do |root|
# Exclude everything
root.exclude(/.*/)
end
# Transformations allows you to change dumped data e. g. to hide sensitive information
config.customize("User") do |user_attributes|
# Reset password for all users to the same for ease of debugging on developer's machine
u["encrypted_password"] = encrypt("qwerty")
u["created_at"] =
# Please note that there you have only hash of record attributes, not the record itself!
end
# Anonymization is a handy DSL for transformations allowing you to transform model attributes in declarative fashion
# Please note that model setters will NOT be called: results of the blocks will be assigned to
config.anonymize("User")
name { Faker::Name.name }
email { Faker::Internet.email }
end
Creating dump
Just call the #dump
method and pass a path where you want your SQL dump file to appear!
require 'evil_seed'
EvilSeed.dump('path/to/new_dump.sql')
Caveats, tips, and tricks
-
Specify
root
s for dictionaries and system-wide models likeRole
at the top without constraints and with all associations excluded. -
Use
exclude
aggressively. You will be amazed, how much your app's models graph is connected. This, in conjunction with the fact that this gem traverses associations in deep-first fashion, sometimes leads to unwanted results: some records will get into dump even if you don't want them. -
Look at the resulted dump: there are some useful debug comments.
Database compatibility
This gem has been tested against:
- PostgreSQL: any version that works with ActiveRecord should work
- MySQL: any version that works with ActiveRecord should work
- SQLite: 3.7.11 or newer is required (with support for inserting multiple rows at a time)
FIXME (help wanted)
-
has_and_belongs_to_many
associations are traversed in a bit nonintuitive way for end user:Association path for
User.has_and_belongs_to_many :roles
isuser.users_roles.role
, but should beuser.roles
-
Test coverage is poor
-
Some internal refactoring is required
Standalone usage
If you want to use it as a standalone application, you can place exerything in a single file like this:
#!/usr/bin/env ruby
require 'bundler/inline'
gemfile do
source 'https://rubygems.org'
gem 'activerecord'
gem 'evil-seed'
gem 'mysql2'
end
# Describe your database layout with ActiveRecord models.
# See http://guides.rubyonrails.org/active_record_basics.html
class Category < ActiveRecord::Base
has_many :translations, class_name: "Category::Translation"
end
class Category::Translation < ActiveRecord::Base
belongs_to :category, inverse_of: :translations
end
# Configure evil-seed itself
EvilSeed.configure do |config|
config.root("Category", "id < ?", 1000)
end
# Connect to your database.
# See http://guides.rubyonrails.org/configuring.html#configuring-a-database)
ActiveRecord::Base.establish_connection(ENV.fetch("DATABASE_URL"))
# Create dump in dump.sql file in the same directory as this script
EvilSeed.dump(File.join(__dir__, "dump.sql").to_s)
And launch it like so:
DATABASE_URL=mysql2://user:pass@host/db ruby path/to/your/script.rb
Development
After checking out the repo, run bin/setup
to install dependencies. Then, run rake test
to run the tests. You can also run bin/console
for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install
. To release a new version, update the version number in version.rb
, and then run bundle exec rake release
, which will create a git tag for the version, push git commits and tags, and push the .gem
file to rubygems.org.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/palkan/evil-seed.
License
The gem is available as open source under the terms of the MIT License.