How to log user_name in Rails?

Question

I use Devise in Rails 3. I want to see name of current_user in production.log.

I would like to configure rails like this:

config.log_tags = [:user_na         


        

Answer 1

Here is the cookie decrypter I use in Rails 5.1 to tag the logs with the user_id, which is stored in the cookie. It basically lets me access the controller equivalent of session[:user_id] from a raw cookie

environments/production.rb:

config.log_tags = [
  :request_id,
  :remote_ip,
  lambda do |req|
    session_data = CookieDecrypter.new(req).session_data
    "user_id:#{session_data['user_id']}"
  end
]

app/models/cookie_decrypter.rb:

class CookieDecrypter
  attr_reader :request

  def initialize(request)
    @request = request
  end

  def session_data
    cookie = request.cookies[session_key]
    return {} unless cookie.present?
    cookie = CGI::unescape(cookie)
    key_generator = ActiveSupport::KeyGenerator.new(secret_key_base, iterations: 1000)
    secret = key_generator.generate_key(salt)[0, ActiveSupport::MessageEncryptor.key_len]
    sign_secret = key_generator.generate_key(signed_salt)
    encryptor = ActiveSupport::MessageEncryptor.new(secret, sign_secret, serializer: JSON)
    encryptor.decrypt_and_verify(cookie) || {}
  end

  private

  def session_key
    Rails.application.config.session_options[:key]
  end

  def secret_key_base
    Rails.application.secrets[:secret_key_base]
  end

  def salt
    Rails.application.config.action_dispatch.encrypted_cookie_salt
  end

  def signed_salt
    Rails.application.config.action_dispatch.encrypted_signed_cookie_salt
  end
end