Use Rails to generate Golang code or manage Go app development

用 Rails 开发 Go 应用：中文文档

go-on-rails is a Rails generator aims to:

1. Help to develop and integrate some APIs written in Golang to existing Rails app for high performance
2. Use your familiar Rails tools to develop and manage a Golang app project
3. Convert a not very complicated Rails app to Golang equivalent

Here's some examples:

• A simple example(tutorial) on the basic usage of go-on-rails generator
• An advanced example shows how to integrate Go APIs in a Rails project
• Another example shows how to handle a Rails session to get a user's info in a go-on-rails generated Go API

• Rails 4.2+ (Rails 6 not supported and need your help)
• Golang 1.10.x(mainly be compatible with github.com/go-sql-driver/mysql)

Add this line to your application's Gemfile:

gem 'go-on-rails', '~> 0.4.0'

And then execute:

$ bundle

Or install it yourself as:

$ gem install go-on-rails

You must have an existing Rails app or to create a new one before you try go-on-rails to generate Golang codes.

After that you can run the command just as other Rails generators:

rails g gor [dev(elopment) | pro(duction) | test | ...] [-m model_a model_b model_c ...]

# OR (on rails version < 5.0)
rake g gor ...

here we take generating all models for the development environment for example:

rails g gor dev

Then a folder named go_app that includes Golang codes will be generated under your Rails app root path.

Install the dependent Golang packages for this Go project:

rails gor:deps

Then change to the go_app directory and run:

go run main.go

You can visit the page in http://localhost:4000 by default.

More command details about go-on-rails generator:

rails g gor --help

• Go project directory layout (all under the go_app directory, like views, controllers, public)
• A Go data struct corresponding to each activerecord model
• And each struct related CRUD functions/methods like FindModel, UpdateModel, DestroyModel etc. All these models related program files under the go_app/models directory
• And godoc files for all the functions under go_app/models/doc
• We use Gin as the default web framework, but you can change it to anyone that you favor in main.go and controllers programs

You can view the godoc page of all functions in http://localhost:7979/doc/models.html after run:

rails gor:doc

Besides, there's a sample project generated by go-on-rails, you can view its godoc at godoc.org just now to get a picture of what functions are generated.

The gem is still under development, so there're some known issues. You're welcomed to contribute. 👏

• databases specific functions between MySQL and Postgres or other databases are not covered completely
• sql.NullType not supported yet, so you'd better in the migrations set those columns "not null" with a default value that's consistent with Golang's zero value specification, such as "" default for string and text typed column, and 0 default for int, etc. And now we have an alternative approach for manipulating the database nullable fields, see the wiki Working with database nullable fields

• Associations
  • has_many
  • has_one
  • belongs_to
  • dependent
• Validations
  • length
  • presence
  • format(string only)
  • numericality(partially)
  • other validations
• Pagination(details see wiki)
• Callbacks
• Transactions

• SQLite
• MySQL
• Postgres

• Built-in Pagination
• Working with database nullable fields
• Some Make commands
• Dockerize a Go-on-Rails application

• github.com/jmoiron/sqlx: an extension on the standard database/sql database API library
• github.com/railstack/go-sqlite3: a SQLite driver(This's a forked version of mattn/go-sqlite3, and This is why we use this forked version)
• github.com/go-sql-driver/mysql: a MySQL driver
• github.com/lib/pq: a PostgreSQL driver
• github.com/asaskevich/govalidator: for the struct validation
• github.com/gin-gonic/gin: a HTTP web framework

When I had the idea to convert Rails app or build Golang app with Rails tools, I searched github and found the project: https://github.com/t-k/ar2gostruct. And from ar2gostruct I copied some codes on handling data structure conversion and models association, it made my idea come true faster than I imagined.

There're two branches at present: master and dev.

The dev branch has a whole Rails environment for development: models, seeds for testing, and under go_app directory there's a file named models_test.go used to test generated Golang codes.

• Fork the project switch to branch dev.
• Make your feature addition or bug fix.
• Add tests for it. This is important so I don't break it in a future version unintentionally.
• Commit, do not mess with Rakefile or version (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
• Send me a pull request. Bonus points for topic branches.

We create four models for testing:

• Physician
• Patient
• Appointment
• Picture

Run rails db:seed to use the data defined in db/seeds.rb. And change to go_app/models directory to run go test to test generated models-related functions. The test covers a small part of the functions currently. More will be added later on.

See the LICENSE file.