Can't get Paperclip to set my S3 URLs properly - ruby-on-rails

Question

I'm using paperclip and aws-sdk gems in a Rails 4 app.
I define the :path option in my paperclip.rb config, with no :url option:
Paperclip::Attachment.default_options[:path] = ":class/:attachment/:id_partition/:style/:filename"
It saves my uploaded images like such:
http://s3.amazonaws.com/mybucket-development/profiles/avatars/000/000/026/original/image_file_name.png?1420575189
All fine, it gets saved to S3. However it refuses to let me read the images for display, e.g. =profile.avatar.url(:medium). When I go to that URL in the browser it tells me to re-format it with the bucket name as a domain. Like:
http://mybucket-development.s3.amazonaws.com/profiles/avatars/000/000/026/original/image_file_name.png?1420575189
OK, not a problem either. I go to that URL, I can view my image. So now I need to figure out how to get Paperclip to format the URLs like this automatically. I read in the Paperclip docs that you just have to set
Paperclip::Attachment.default_options[:url] = ":s3_domain_url"
And that I also have to set the :path parameter or I will just get a Paperclip::Errors::InfiniteInterpolationError.
So I set my config file with both combined:
Paperclip::Attachment.default_options[:path] = ":class/:attachment/:id_partition/:style/:filename"
Paperclip::Attachment.default_options[:url] = ":s3_domain_url"
Not working... I try scrapping the paperclip.rb and putting it in config/environments/* But no matter what I do, it still saves the URLs without the domain with the bucket name in the path.
So two questions:
1) How can I get Paperclip to automatically format the saved URLs in domain style?
2) Or even better, how can I get S3 to accept the non-domain style URLs, the one that Paperclip is currently generating?
EDIT
So, if I add in the s3_host_name option then it saves the URLs domain style. So I have to have all 3 of:
Paperclip::Attachment.default_options[:url] = ':s3_domain_url'
Paperclip::Attachment.default_options[:path] = ":class/:attachment/:id_partition/:style/:filename"
Paperclip::Attachment.default_options[:s3_host_name] = 's3-us-west-2.amazonaws.com'
And it will save my URLs on the model like so:
http://mybucket-development.s3-us-west-2.amazonaws.com/profiles/avatars/000/000/026/original/image_file_name.png%3F1420580224
But now I see that I have a %3F encoding ("?") in the URL which messes it up.

Answer 1

Alright, so as mentioned in the above update, to get the domain-style URLs to be saved by Paperclip I have to include all 3 of the following in my paperclip.rb:
Paperclip::Attachment.default_options[:url] = ':s3_domain_url'
Paperclip::Attachment.default_options[:path] = ":class/:attachment/:id_partition/:style/:filename"
Paperclip::Attachment.default_options[:s3_host_name] = 's3-us-west-2.amazonaws.com'
I believe there is a related issue from recent gem upgrades, this produces URLs with encodings that won't work on their own.
So in my views I have had to add URI.unescape, such as
=image_tag URI.unescape(profile.avatar.url(:medium))
I could also set a callback on the model to replace the %3F with the "?" before save.
Strange issue with Paperclip... not sure what was going on. First app I've worked on where I encountered that issue.

Answer 2

In paperclip.rb
Paperclip::Attachment.default_options[:s3_host_name] = 's3-ap-south-1.amazonaws.com'
In production.rb
config.paperclip_defaults = {
storage: :s3,
s3_protocol: :https,
s3_credentials: {
bucket: ENV.fetch('S3_BUCKET_NAME'),
access_key_id: ENV.fetch('AWS_ACCESS_KEY_ID'),
secret_access_key: ENV.fetch('AWS_SECRET_ACCESS_KEY'),
s3_region: ENV.fetch('AWS_REGION')
}
This pretty much worked well for me with image_tag. It should work for you too.