部署在Heroku的Rails应用无法加载AWS S3 Bucket中的图片求助

Let's walk through this step by step—first, let's clear up your Procfile question, then dig into why those S3 images aren't loading.

First: The Procfile Isn't Your Problem #

Procfiles on Heroku are for defining how your app's processes run (like specifying a web server or worker). For Rails apps, Heroku will default to running rails server if you don't have a Procfile, as long as your app is set up correctly. So missing a Procfile isn't causing your image loading issues—we can rule that out right away.

Now: Fixing the S3 Image Loading #

Let's start with the most obvious issue in your example, then move to common configuration pitfalls:

1. Fix the Typo in Your Image URL #

Looking at your img tag:

<img class="d-block w-100" src="https://s3-ap-southeast- 1.amazonaws.com/globalenglish1/EnglishUp-113.jpg">

There's a space in the region part (ap-southeast- 1 instead of ap-southeast-1). That's guaranteed to break the URL. Remove that space first, then test accessing the URL directly in your browser—if it loads, you're halfway there.

2. Verify S3 Bucket & Object Permissions #

If the corrected URL still doesn't load, check your S3 settings:

• Public Access Settings: Go to your S3 bucket's "Permissions" tab, then "Block public access". If you're serving public images, make sure you haven't blocked all public access (you can keep "Block public access to buckets and objects granted through new access control lists" enabled, but uncheck the other boxes if needed).
• Bucket Policy: Add a policy that allows public read access to your objects (only do this if you want these images to be public):

  {
    "Version": "2012-10-17",
    "Statement": [
      {
        "Effect": "Allow",
        "Principal": "*",
        "Action": "s3:GetObject",
        "Resource": "arn:aws:s3:::globalenglish1/*"
      }
    ]
  }
  

• Object-Level Permissions: Check the individual image's permissions in S3—ensure it has "Read" access for "Everyone (public access)".

3. Configure CORS for Cross-Domain Loading #

Since your Heroku app is a different domain than S3, you need to set up CORS rules on your bucket to allow browsers to load the images:

1. Go to your bucket's "Permissions" tab > "Cross-origin resource sharing (CORS)".
2. Add this configuration (adjust the AllowedOrigin to your Heroku app's domain if you don't want to allow all origins):

   <?xml version="1.0" encoding="UTF-8"?>
   <CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
   <CORSRule>
       <AllowedOrigin>https://your-heroku-app-name.herokuapp.com</AllowedOrigin>
       <AllowedMethod>GET</AllowedMethod>
       <AllowedHeader>*</AllowedHeader>
   </CORSRule>
   </CORSConfiguration>
   

4. Validate Your Rails & Heroku Environment Setup #

If you're using Rails with AWS SDK (like aws-sdk-s3 or Active Storage):

• Ensure your config/environments/production.rb has the correct S3 config:

  # If using Active Storage
  config.active_storage.service = :amazon
  
  # If using direct AWS calls
  Aws.config.update({
    region: 'ap-southeast-1',
    credentials: Aws::Credentials.new(ENV['AWS_ACCESS_KEY_ID'], ENV['AWS_SECRET_ACCESS_KEY'])
  })
  

• Confirm your Heroku environment variables are set correctly. Run heroku config in your terminal—you should see AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and S3_BUCKET_NAME (or whatever keys you're using) with valid values.

5. Check Browser Dev Tools for Clues #

If none of the above works, open your browser's developer tools (F12), go to the Network tab, and reload the page. Look at the image request:

• A 403 Forbidden error means permission issues (go back to step 2).
• A 404 Not Found error means the image doesn't exist in the bucket (double-check the file path and name).
• A CORS-related error means your CORS config is wrong (step 3).

内容的提问来源于stack exchange，提问作者Robert