Different S3 buckets for staging app vs. production app

Question

I have a Rails app that uses Amazon S3 to store Paperclip attachments. My database.yml file specifies different S3 buckets for development, test, and production.

I have two apps on Heroku - a production app and a 'staging app' for testing code on the platform pre-launch.

The current system has an important flaw - it uses the same S3 bucket for staging and production. How can I set up my system so it uses different buckets depending essentially on whether I write git push production master or git push staging master?

Answer 1

Heroku permits you to configure anything you like via persistent environment variables that every dyno/process in an application gets started with. Environment variables are not shared between staging and production versions of the same application. Take advantage of this.

has_attached_file :photo, 
  :styles => ...,
  :path => ...,
  :storage => :s3,
  :bucket => ENV['S3_BUCKET'], # <--- over here
  :s3_credentials => {
    :access_key_id => ENV['S3_KEY'],
    :secret_access_key => ENV['S3_SECRET']
  }

Then:

# Configure the "staging" instance
$ heroku config:add \
    RACK_ENV=production \
    S3_KEY=my-staging-key \
    S3_SECRET=my-staging-secret \
    S3_BUCKET=my-staging-bucket \
    --app my-staging-app-name

# Configure the "production" instance
$ heroku config:add \
    RACK_ENV=production \
    S3_KEY=my-production-key \
    S3_SECRET=my-production-secret \
    S3_BUCKET=my-production-bucket \
    --app my-production-app-name

Note that each instance of your application has a RACK_ENV=production. Don't use Rails environments for differentiating between instances of your application. Rather, your application should expect that environment variables be used to configure instance-specific aspects.

Answer 2

Set config:add RACK_ENV=staging on your staging box, and then in your code you can specify the bucket depending on the environment. Eg:

if Rails.env.production?
    has_attached_file :photo, 
    :styles => ...,
    :path => ...,
    :storage => :s3,
    :bucket => 'your_prod_bucket',
    :s3_credentials => {
      :access_key_id => ENV['S3_KEY'],
      :secret_access_key => ENV['S3_SECRET']
    }
  else
    has_attached_file :photo, 
    :styles => ...,
    :path => ...,
    :storage => :s3,
    :bucket => 'your_staging_bucket',
    :s3_credentials => {
      :access_key_id => ENV['S3_KEY'],
      :secret_access_key => ENV['S3_SECRET']
    }

  end

This heroku post also seem to suggest that you can achieve this simply by using different s3 credentials for staging and production. I'm guessing you'd have to do some configuration on amazon's side as well. Anyways, take a look to see if it helps. http://devcenter.heroku.com/articles/config-vars