Rails中无法接收SendGrid Webhook响应的问题求助

Hey there! As someone who's wrestled with SendGrid webhooks in Rails before, let's walk through the most likely issues and fixes for your problem:

1. Your Local Endpoint Isn't Accessible to SendGrid #

First off—http://localhost:8090 is only reachable on your own machine. SendGrid's servers can't send requests to your local development environment directly. That's probably why the SendGrid test tool isn't hitting your controller at all.

Fix this with a tunneling tool:

• Use something like ngrok to expose your local server to the public internet. Run this command in your terminal (make sure your Rails server is running on port 8090 first):

  ngrok http 8090
  

• Ngrok will give you a public URL (like https://xyz789.ngrok.io). Update your SendGrid Webhook settings to use this URL plus your endpoint path: https://xyz789.ngrok.io/apis/email_events

2. Validate Request Parsing & CSRF Settings #

You've added protect_from_forgery with: :null_session, but there might still be issues with how Rails parses SendGrid's JSON payload:

• SendGrid sends webhook data with Content-Type: application/json, so ensure your controller is handling raw JSON correctly. Add a before_action to parse the payload:

  class ApisController < ApplicationController
    protect_from_forgery with: :null_session
    before_action :parse_sendgrid_payload
  
    def email_events
      # Use @payload to access the parsed event data
      @payload.each do |event|
        email = event["email"]
        event_type = event["event"]
        Rails.logger.info "Received #{event_type} event for #{email}"
      end
      head :ok # Critical: SendGrid needs a 200 OK response
    end
  
    private
  
    def parse_sendgrid_payload
      request.body.rewind
      @payload = JSON.parse(request.body.read) if request.content_type == "application/json"
    end
  end
  

• For API-only controllers, consider inheriting from ActionController::API instead of ApplicationController—it skips unnecessary middleware that can interfere with webhook requests.

3. Check Your Rails Logs Again (Carefully!) #

If you don't see any incoming request in your log/development.log when triggering the SendGrid test, that confirms the issue is reachability (point 1). If you do see the request, look for:

• Any parsing errors when accessing params["_json"]
• Whether your controller is sending a 200 response (SendGrid will retry if it gets anything else)

4. Double-Check SendGrid's Webhook Configuration #

• Make sure you've selected the events you want to track (e.g., delivered, opened, bounced) in SendGrid's settings—if no events are selected, SendGrid won't send any payloads.
• Confirm the HTTP method is set to POST (it's the default, but it never hurts to check).
• Use SendGrid's "Test Your Integration" button after updating to the ngrok URL—this will send a test payload to your endpoint.

5. Ensure You're Sending a Proper Response #

SendGrid expects a 200 OK response within 30 seconds. If your controller action doesn't explicitly send a response (like head :ok), Rails might send a default response that SendGrid doesn't recognize, leading to retries or failed deliveries.

内容的提问来源于stack exchange，提问作者john