CarrierWave on Heroku with CloudFront
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Join For FreeThis post will enable you to have your Rails app accept file uploads through a gem called CarrierWave. Optionally, you can use CloudFront in order to have a CDN backbone for those files. This is currently the best method for file uploading on Heroku.
For a full-fledged working project with this on Heroku's cedar stack, check out http://github.com/dickeytk/painting-gallery
Prerequisites
- Go to S3 and get an AWS Access Key ID and an AWS Secret Access Key.
- Create a new S3 bucket in the US East Availability Zone. (Since that's the same one that your Heroku dyno is already in)
- If you want to use CloudFront, add a CloudFront distribution pointing to the S3 bucket you just created.
Instructions
Add the gems to your Gemfile:
gem 'fog' gem 'carrierwave' gem 'rmagick' # optional, for image resizing support
Add the file './config/initializers/carrierwave.rb' for your CarrierWave configuration:
# ./config/initializers/carrierwave.rb CarrierWave.configure do |config| config.fog_credentials = { :provider => "AWS", :aws_access_key_id => ENV['AWS_ACCESS_KEY_ID'], :aws_secret_access_key => ENV['AWS_SECRET_ACCESS_KEY'], } config.fog_directory = ENV['S3_BUCKET'] # use only one of the following 2 settings config.fog_host = "http://#{ENV['S3_BUCKET']}.s3.amazonaws.com" # for no cloudfront config.fog_host = ENV['S3_CDN'] # for cloudfront end
Add your environment variables:
$ heroku config:add AWS_ACCESS_KEY_ID=[your_access_key_here] $ heroku config:add AWS_SECRET_ACCESS_KEY=[your_access_key_here] $ heroku config:add S3_BUCKET=[your_s3_bucket] $ heroku config:add S3_CDN=[your_cloudfront_url] # optional for cloudfront support
That's it! Should be configured now. All you need to do is add a string column to a model for the file name, a file uploader to add files to a model, and a form to actually accept the uploads. CarrierWave's docs explain how to do that all very well.
Using your own domain
If you want to use your own domain (such as content.jeffdickey.info like I use on this site) simply add a CNAME in your dns config pointing to the S3 bucket, then change the S3_CDN environment variable to point to it.
Optional CloudFront note
Now, if you are going to use CloudFront, you should add this bit to your uploader which will append a file's hash to the end of a filename. This is so CloudFront won't cache old content.
# ./app/uploaders/image_uploader.rb # ... # Appends hash to filename to prevent CloudFront from caching old content def filename if original_filename @hash ||= Digest::MD5.hexdigest(File.dirname(current_path)) "#{file.basename.split('_').last}-#{@hash}.#{file.extension}" end end
Known issue
There is a potential issue to look out for here. Uploading files that will take >30 seconds will result in Heroku killing the request, so you need to directly upload the files. This S3 SWF upload plugin should help with that. But don't throw that on just 'because'. It's likely to just cause grief.
Summary
I hope this works out well for you! I've configured this type of setup several times now and seems to work great! I did it all from memory though, so let me know if you run into any issues.
Source: http://jeffdickey.info/using-carrierwave-on-heroku-for-image-uploading-w-cloudfront
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