ferry

What is Ferry?

Ferry is a command-line tool rubygem designed for Rails data migrations and manipulation, primarily maintained as an open-source project by the students of Carnegie Mellon’s Information Systems department since August 2014. The inspiration for ferry was brought from collective internship experiences and from the growing prevalence of big data migration and manipulation challenges that companies, corporations, universities, and organizations face in today’s information age. A large thanks in part to CustomInk’s Technology Team and their blog articles for advice and guidance during the first semester (Fall 2014) of development.

What can I use Ferry for?

See the ferry_demo app or our GitHub pages site for further documentation on using Ferry!

Rails Migration and Manipulation use cases

• Exporting and Importing data to various file formats (.csv, .yml, .json, .sql)
• Migrating data to third party services (Amazon S3, Oracle) and different databases and manipulating data via a Custom Built DSL (see coming soon)

Coming soon …

• Configurable Migration Scripting
  • The idea behind this feature is for developers to provide options for arguments in an executable script that contains the configuration and necessary tasks/ actions for the operations of whatever data migration or manipulation they are seeking to carry out.
  • Similar to how capistrano configures deploy.rb.
  • To do this we will be investigating custom DSL’s and building our own in order to provide a quick and easy solution that will allow developers to carry out complex migration and manipulation strategies in just an afternoon!
• Data Visualization
  • With inspiration from d3, we are hoping to create functionality that allows developers to deploy informative and visually appealing graphs and documents that can be shared over an internal network to be broadcasted to servers for display either on internal office displays or to URL’s … all from executing a simple command-line statement.
  • We will be making use of d3 for visualizations and are looking for current solutions to this business need and if there are any successful or not-so-successful solutions out there to compete with.
  • After some consideration, this will either be built into our DSL or pulled out into a separate gem that does data proessing and visualization all on its own.

Installation

Add this line to your Rails application’s Gemfile:

gem 'ferry'

And then execute:

$ bundle

Or install it yourself as:

$ gem install ferry

To view what Ferry can do for you just run:

$ ferry --help

Exporting

Ferry can export data from a database connected to a Rails app into a CSV or YAML file.
We currently only support exporting of SQLite3, MySQL2, and PostgreSQL databases.

Run ferry --to_csv [environment] [table] in your Rails directory to export to csv:

$ ferry --to_csv production users

Running the above command will export the “users” table from the database connected to the “production” environment.
A csv file populated with the “users” table data will be created at /db/csv/test/users.csv (the path will be created and if there is a users.csv it will be overwritten).

Run ferry --to_yaml [environment] [table] in your Rails directory to export to yaml:

$ ferry --to_yaml development users

Similarly, running the above command in the Rails directory will export the “users” table from the database connected to the “development” environment.
A yaml file populated with the “users” table data will be created at /db/yaml/test/users.yaml (the path will be created and if there is a users.yaml it will be overwritten).

Run ferry --to_json [environment] [table] in your Rails directory to export to json:

$ ferry --to_json development users

Similarly, running the above command in the Rails directory will export the “users” table from the database connected to the “development” environment.
A json file populated with the “users” table data will be created at /db/yaml/test/users.json (the path will be created and if there is a users.json it will be overwritten).

Importing

Ferry can import a csv or json file of validated records into a table of a Rails-connected database.
The csv and json files must:

• Have headers (or keys) that match field names of the table
• Have values that meet the table’s constraints (i.e. required fields, correct data types, unique PKs, etc.)

Run ferry --import_csv [environment] [table] [file path] in your Rails directory to import a csv to a database table:

$ ferry --import_csv development users db/csv/import_data.csv

Running the above command will import the import_data.csv to the “users” table in the “development” environment, and the same goes for ferry --import_json

Dumping and Filling .sql

Ferry can either dump or fill your current database to a .sql file or with reference to a .sql file you would like to import respectively with just these simple commands.

$ ferry --dump [environment]
$ ferry --fill [environment] [path/to/file.sql]

Where [environment] is just the development, production, test, etc database environment you are developing with.

Contributing

1. Fork it ( https://github.com/[my-github-username]/ferry/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

If you wish to open a pull request or issue for anything at all please feel free to do so!

A large driving factor in the development of Ferry is contributing something meaningful to the open-source community and the developer community at large. Being college students who have access to such an unbelievable amount of developement resources for creating cool projects, we felt a need to give back - we wanted to start a project that would face unique challenges such that others who face similar challenges could turn to us for help and guidance. We hope that Ferry continues to be a project that both provides benefit to businesses and developers along with giving back to the open-source and greater developer community.