```ruby
class Item < ApplicationRecord
  belongs_to :user
  belongs_to :section
  has_attached_file :image,
    storage: :s3,
    s3_credentials: {access_key_id: ENV["AWS_KEY"], secret_access_key: ENV["AWS_SECRET"]},
    bucket: "neverevernude"

  validates :user_id, :section_id, presence: true
  validates_attachment_presence :image
  validates_attachment_content_type :image, :content_type => /\Aimage\/.*\Z/
end
```

Add sizes to image model
user
```ruby
class Item < ApplicationRecord
  belongs_to :user
  belongs_to :section
  has_attached_file :image,
    :styles => {
      :thumb => "100x100#",
      :small  => "150x150>",
      :medium => "200x200" },
    storage: :s3,
    s3_credentials: {access_key_id: ENV["AWS_KEY"], secret_access_key: ENV["AWS_SECRET"]},
    bucket: "neverevernude"

  validates :user_id, :section_id, presence: true
  validates_attachment_presence :image
  validates_attachment_content_type :image, :content_type => /\Aimage\/.*\Z/
end
```
assistant