AWS Api Gateway as a HTTP Proxy is currupting binary uploaded image files

Question

I have a ruby on rails app that takes an image file, "attaches it to a member", and uploads it to s3. When I use insomnia and POST directly to the app ... it works, however when I use the exact same endpoint behind AWS Api Gateway, the image is corrupt and not viewable.

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Here is the comparison of the requests.

• LEFT = directly posted to the rails app
• RIGHT = through api gateway

https://www.diffchecker.com/wwUmpB5W

Something I noticed, is that the paperclip gem is running different commands. It's evident that paperclip realized that the file is not an image when being passed through API gateway.

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Here are some potentially relevant screenshots

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Here is the rails code:

def create
  logger.info 'upload_attachment_api_general_v1'
  logger.info params
  logger.info request.env
  @file = current_merchant.members.find(params[:member_id]).attachments.new(file: params[:file], label: params[:label])
  if params[:file] && @file.save
    render json: @file
  else
    render json: @file.errors, status: :unprocessable_entity
  end
end

Answer 1

I figured it out. The content type is NOT an image/png ... the content type is multipart/form-data