Why ngrok send me a 403 Forbidden

Question

I try to work with a webhook to get a JSON, I read that I should install ngrok because webhooks do not work locally, so I installed ngrok, and tried to follow this small tuto : https://medium.com/@derek_dyer/rails-webhooks-local-development-7b7c755d85e3

I created my routes :

get 'invoice/webhooks'
post 'invoice/webhooks' =>'invoice#webhooks'

And my controller :

def webhooks
   render json: response.body, status: 200
end

I also plugged my URL : https://ce0d99f7.ngrok.io/invoice/webhooks in my service to receive the webhook

I run ./ngrok http 3000 in my terminal and I receive a message

POST /invoice/webhooks         403 Forbidden

Is anyone knows how to fix that ?

Answer 1

If you using rails 6 and use ngrok in development you must edit the development.rb file in config/environments for add config.hosts << "a0000000.ngrok.io" where a0000000.ngrok.io is the url supplied by ngrok without https:// , if this no work so you must add skip_before_action :verify_authenticity_token in you controller.

Answer 2

@daniel0318's answer is exactly right. I just wanted to mention you can use this regular expression to allow all traffic through ngrok (add to development.rb):

# /config/environments/development.rb

config.hosts << /[a-z0-9-]+\.ngrok\.io/

Restart your server, and it will work.

One last note: if you think you already have this regex in place, please look carefully, since ngrok URL formats changed some time in the past few months, and now contain - characters. Tl;dr, config.hosts << /[a-z0-9-]+\.ngrok\.io/ works, but the old regex: config.hosts << /[a-z0-9]+\.ngrok\.io/ (same but not allowing dashes) will not work!