oauth2_sinatra_client.rb

require "sinatra"
require "oauth2"

DB = {
  site: "http://api.local.com:3000/",
  redirect_uri: "http://oauth2client:1758/callback"
}

get "/" do
  DB[:uid] = params[:uid]
  DB[:secret] = params[:secret]

  client = OAuth2::Client.new( DB[:uid], DB[:secret], site: DB[:site])
  url = client.auth_code.authorize_url( redirect_uri: DB[:redirect_uri])

  redirect url
end

get "/callback" do
  client = OAuth2::Client.new( DB[:uid], DB[:secret], site: DB[:site])
  token = client.auth_code.get_token(params[:code], :redirect_uri => DB[:redirect_uri])

  %{
    connected:
    <br/><br/>
    #{token.to_hash}
  }
end