OAuth2 with rails / ruby

Doorkeeper

location: `config/initializers/doorkeeper.rb`:
```
  resource_owner_authenticator do
    current_user || begin
      session[:user_return_to] = request.fullpath
      redirect_to new_user_session_url
    end
  end
```

if you want to skip authorize:
```
  skip_authorization do
    true
  end
```

location `controllers`:
Paste this code under class
`before_action :doorkeeper_authorize!`

Check link, expected to get status code 401

Testing Client

Testing oauth2 in ruby
------------------------------------------------
$ gem install oauth2
$ irb -r oauth2

host_provider = 'http://localhost:3000'
callback = 'your callback link'
app_id = 'paste app id'
secret = 'paste secret'
client = OAuth2::Client.new(app_id, secret, site: host_provider)

#get code
client.auth_code.authorize_url(redirect_uri: callback)
#copy link and paste to browser, and then click allow/authorize

#paste code from query string
code = 'paste code from url'

access = client.auth_code.get_token(code, redirect_uri: callback)

#get access_token
access.token

#check token expired
access.expired?

#refresh token
access.refresh_token
new_access = access.refresh!
new_access.token

Testing Oauth2 client via curl

host_provider = 'http://localhost:3001'
callback = 'http://localhost:3002/auth/moka/callback'
app_id = 'df9b60aa6a4198da1bf216cbe2b5c9bb0edf0d2049e27ba970f787de33c04587'
secret = 'de113c590c9a3809b35b09665d6dd795b336a9094218561f3932e2f42194d8e6'
client = OAuth2::Client.new(app_id, secret, site: host_provider)

#get code
client.auth_code.authorize_url(redirect_uri: callback)


# GET access_token
curl -F grant_type=authorization_code \
-F client_id=df9b60aa6a4198da1bf216cbe2b5c9bb0edf0d2049e27ba970f787de33c04587 \
-F client_secret=de113c590c9a3809b35b09665d6dd795b336a9094218561f3932e2f42194d8e6 \
-F code=957caa08d20e3de0546a2620bc43b4c4e1e1df449f1af0683f86813d4ddf2836 \
-F redirect_uri=http://localhost:3002/auth/moka/callback \
-X POST http://localhost:3001/oauth/token

#refresh token
curl -F grant_type=refresh_token \
-F client_id=df9b60aa6a4198da1bf216cbe2b5c9bb0edf0d2049e27ba970f787de33c04587 \
-F client_secret=de113c590c9a3809b35b09665d6dd795b336a9094218561f3932e2f42194d8e6 \
-F refresh_token=6886d655d42c97193df2082e5f4b639e017810fd4025ddc5b5a6b6f00c05a941 \
-X POST http://localhost:3001/oauth/token

#info token
curl -H "Authorization: Bearer bba8528f068839e0417459e18d112e78a4874ee9889201b0f331f709d5f21cad" \
localhost:3001/oauth/token/info