Rails + Devise_token_authのTwitter認証でOAuth::Unauthorized 403 Forbidden

Question

devise_token_authとomniauth-twitterを使って、twitterで認証しログインできるようにしたいです。
設定はこのような感じです。

# config/initializers/omniauth.rb
Rails.application.config.middleware.use OmniAuth::Builder do
  provider :twitter,        ENV['TWITTER_KEY'],   ENV['TWITTER_SECRET']
end

rails.application.routes.draw do
   mount_devise_token_auth_for 'User', at: 'auth'
end

class User < ActiveRecord::Base
    devise :database_authenticatable, :recoverable,
           :trackable, :validatable, :registerable,
           :omniauthable
    include DeviseTokenAuth::Concerns::User
end

http://lcoalhost:3000:/auth/twitter にGETすると、
OAuth::Unauthorized 403 Forbiddenというエラーが出ます。

Started GET "/auth/twitter" for 127.0.0.1 at 2018-05-25 18:44:52 +0900
Started GET "/omniauth/twitter?resource_class=User" for 127.0.0.1 at 2018-05-25 18:44:52 +0900
I, [2018-05-25T18:44:52.686590 #23277]  INFO -- omniauth: (twitter) Request phase initiated.
  
OAuth::Unauthorized (403 Forbidden):
  
oauth (0.5.4) lib/oauth/consumer.rb:236:in `token_request'
oauth (0.5.4) lib/oauth/consumer.rb:155:in `get_request_token'
omniauth-oauth (1.1.0) lib/omniauth/strategies/oauth.rb:28:in `request_phase'
omniauth-twitter (1.4.0) lib/omniauth/strategies/twitter.rb:61:in `request_phase'
omniauth (1.8.1) lib/omniauth/strategy.rb:224:in `request_call'
omniauth (1.8.1) lib/omniauth/strategy.rb:187:in `call!'
omniauth (1.8.1) lib/omniauth/strategy.rb:168:in `call'
omniauth (1.8.1) lib/omniauth/builder.rb:63:in `call'
rack (2.0.5) lib/rack/method_override.rb:22:in `call'
rack (2.0.5) lib/rack/session/abstract/id.rb:232:in `context'
rack (2.0.5) lib/rack/session/abstract/id.rb:226:in `call'
actionpack (5.1.6) lib/action_dispatch/middleware/cookies.rb:613:in `call'
warden (1.2.7) lib/warden/manager.rb:36:in `block in call'
warden (1.2.7) lib/warden/manager.rb:35:in `catch'
warden (1.2.7) lib/warden/manager.rb:35:in `call'
rack (2.0.5) lib/rack/etag.rb:25:in `call'
rack (2.0.5) lib/rack/conditional_get.rb:25:in `call'
rack (2.0.5) lib/rack/head.rb:12:in `call'
rack (2.0.5) lib/rack/session/abstract/id.rb:232:in `context'
rack (2.0.5) lib/rack/session/abstract/id.rb:226:in `call'
actionpack (5.1.6) lib/action_dispatch/middleware/cookies.rb:613:in `call'
activerecord (5.1.6) lib/active_record/migration.rb:556:in `call'
actionpack (5.1.6) lib/action_dispatch/middleware/callbacks.rb:26:in `block in call'
activesupport (5.1.6) lib/active_support/callbacks.rb:97:in `run_callbacks'
actionpack (5.1.6) lib/action_dispatch/middleware/callbacks.rb:24:in `call'
actionpack (5.1.6) lib/action_dispatch/middleware/executor.rb:12:in `call'
actionpack (5.1.6) lib/action_dispatch/middleware/debug_exceptions.rb:59:in `call'
web-console (3.6.2) lib/web_console/middleware.rb:135:in `call_app'
web-console (3.6.2) lib/web_console/middleware.rb:30:in `block in call'
web-console (3.6.2) lib/web_console/middleware.rb:20:in `catch'
web-console (3.6.2) lib/web_console/middleware.rb:20:in `call'
actionpack (5.1.6) lib/action_dispatch/middleware/show_exceptions.rb:31:in `call'
railties (5.1.6) lib/rails/rack/logger.rb:36:in `call_app'
railties (5.1.6) lib/rails/rack/logger.rb:24:in `block in call'
activesupport (5.1.6) lib/active_support/tagged_logging.rb:69:in `block in tagged'
activesupport (5.1.6) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (5.1.6) lib/active_support/tagged_logging.rb:69:in `tagged'
railties (5.1.6) lib/rails/rack/logger.rb:24:in `call'
actionpack (5.1.6) lib/action_dispatch/middleware/remote_ip.rb:79:in `call'
actionpack (5.1.6) lib/action_dispatch/middleware/request_id.rb:25:in `call'
rack (2.0.5) lib/rack/method_override.rb:22:in `call'
rack (2.0.5) lib/rack/runtime.rb:22:in `call'
activesupport (5.1.6) lib/active_support/cache/strategy/local_cache_middleware.rb:27:in `call'
actionpack (5.1.6) lib/action_dispatch/middleware/executor.rb:12:in `call'
actionpack (5.1.6) lib/action_dispatch/middleware/static.rb:125:in `call'
rack (2.0.5) lib/rack/sendfile.rb:111:in `call'
rack-cors (1.0.2) lib/rack/cors.rb:97:in `call'
webpacker (3.5.3) lib/webpacker/dev_server_proxy.rb:22:in `perform_request'
rack-proxy (0.6.4) lib/rack/proxy.rb:57:in `call'
railties (5.1.6) lib/rails/engine.rb:522:in `call'
puma (3.11.4) lib/puma/configuration.rb:225:in `call'
puma (3.11.4) lib/puma/server.rb:632:in `handle_request'
puma (3.11.4) lib/puma/server.rb:446:in `process_client'
puma (3.11.4) lib/puma/server.rb:306:in `block in run'
puma (3.11.4) lib/puma/thread_pool.rb:120:in `block in spawn_thread'

このエラーを解決したいです。

Answer 1

僕も同じところで長い間苦しみました。
以下僕の場合の解決方法です。

$ rails routes

を実行すると(僕はusersにマウントしていたので以下の通り)

user_twitter_omniauth_callback GET|POST /users/auth/twitter/callback(.:format)                                                   users/omniauth_callbacks#twitter

callbackのルーティングがあると思います。
つまり(僕の場合)localhostでのcallbackURLは

http://127.0.0.1:3000/users/auth/twitter/callback

となるのですが、Twitter側のcallbackURLが間違えていました。
Twitter側のcallbackURLを修正したところ上手くいきました。

Answer 2

http://localhost:3000 ではなく　http://127.0.0.1:3000　でした