Rack middleware that explicitely acquires a Sequel database connection for entire request. It's reasonable if you want a Rails-like behaviour where database connection is released by the ActiveRecord::ConnectionAdapters::ConnectionManagement middleware at the end of request.

But please use it with warning that using Rack::WithSequel you'll get every request locking one connection from the pool even if database is not used during this request (for example, Rails acquires a connection only when it's needed).

Add this line to your application's Gemfile:

gem 'rack-with_sequel'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rack-with_sequel

use Rack::WithSequel

By default it will wrap every request in Sequel::Model.db.synchronize do ... end.

Suppose we have a PostgreSQL connection somewhere:

DB = Sequel.connect("postgres://postgres:postgres@localhost:5432/test")

Then we can pass it to the middleware as an option:

use Rack::WithSequel, db: DB

So DB will be used instead of Sequel::Model.db.

Minimal example:

require 'sinatra'
require 'rack/with_sequel'

db = Sequel.connect("postgresql://postgres:postgres@localhost:5432/test")

use Rack::WithSequel, db: db

get '/' do
  puts db[:test].all.inspect
end

Sometimes it's reasonable to handle connection errors. In this case it's recommended to define a custom middleware:

require 'rack/with_sequel'

class CustomWithSequel < Rack::WithSequel
  ERRORS = [Sequel::DatabaseConnectionError, Sequel::PoolTimeout]

  def call(env)
    super
  rescue *ERRORS
    [503, {}, ["database connection error"]]
  end
end

# ...

use CustomWithSequel

1. Fork it ( https://github.com/marshall-lee/rack-with_sequel/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